sda containerships procedure august 2017 final …...greater than 150 m and for other container...

ShipRight Design and Construction Structural Design Assessment Primary Structure of Container Ships August 2017

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Document History

Document Date: Notes:

May 2000 Preliminary release.

November 2001 Preliminary editorial revisions.

July 2002 Final release.

October 2002 External revisions.

May 2004 Revisions as identified in Notice – ‘Changes incorporated in May 2004 version’.

May 2006 Revisions as identified in Notice – ‘Changes incorporated in May 2006 version’.

March 2016 Revisions as identified in ‘Notice 1 – SDA Primary Structure of Container Ships, March 2016 version’.

September 2016 Consolidated version incorporating: ‘Notice 1 – SDA Primary Structure of Container Ships, March 2016 version’, IACS Unified Requirement S34 (May 2015) and Corrigenda.

August 2017 Revisions as identified in ‘Notice 1 – SDA Primary Structure of Container Ships, August 2017 version’.

© Lloyd's Register Group Limited 2017. All rights reserved. Except as permitted under current legislation no part of this work may be photocopied, stored in a retrieval system, published, performed in public, adapted, broadcast, transmitted, recorded or reproduced in any form or by any means, without the prior permission of the copyright owner. Enquiries should be addressed to Lloyd's Register Group Limited, 71 Fenchurch Street, London, EC3M 4BS.

Primary Structure of Container Ship, August 2017

1

CONTENTS

INTRODUCTIONSection 1: Application .................................................................................................................. 3

Section 2: Symbols ....................................................................................................................... 4

Section 3: Direct calculation procedures report .......................................................................... 6

PART A: Global Model of Complete Ship ................................................................................................ 8

Chapter 1: Analysis of Global Loads .................................................................................................... 8

Section 1: Application .................................................................................................................. 8

Section 2: Objectives .................................................................................................................... 8

Section 3: Structural modelling .................................................................................................... 9

Section 4: Loading conditions .................................................................................................... 13

Section 5: Boundary conditions ................................................................................................. 22

Section 6: Acceptance criteria ................................................................................................... 24

PART B: Verification of Structural Components and Details ................................................................. 28

Chapter 1: Analysis of Global Loads on Local Details........................................................................ 28

Section 1: Application ................................................................................................................ 28

Section 2: Objectives .................................................................................................................. 28

Section 3: Structural modelling .................................................................................................. 29

Section 4: Loading and boundary conditions ............................................................................. 33


PART C: Verification of Primary Structure ............................................................................................ 39

Chapter 1: Verification of Double Bottom and Transverse Strength ................................................ 39








Chapter 2: Transverse Bulkhead and Mid‐Hold Support Structures: Surge (Fore and Aft) Loading . 58




Primary Structure of Container Ship, August 2017

2




Chapter 3: Transverse Watertight Bulkhead Assessment in Damaged (Flooded Hold) Condition ... 61






Chapter 4: Transverse Bulkhead Structures: Additional Requirements for Fuel Oil Deep Tanks ...... 67








Chapter 5: Surge (Fore and Aft) Loading: Additional Requirements for Fuel Oil Deep Tanks ........... 89



Section 3: Loading condition ...................................................................................................... 89

Appendix A: Procedure to Apply Transverse Asymmetric Loads to a Half‐Breadth Model……………….91

Appendix B: Combined Stresses Analysis in Oblique Sea Based on Equivalent Design Waves………….93

Appendix C: Rule Equivalent Design Wave Hydrodynamic Torque, Vertical and Horizontal Bending

Moment Distributions...............................................................................………….....…...……………………97

Appendix D: Combined Direct Stresses in Oblique Sea (Alternative Method)…………………………………103

Introduction Primary Structure of Container Ship, August 2017

3

INTRODUCTION

Section 1: Application

Section 2: Symbols

Section 3: Direct calculation procedures report


1.1. TheShipRightStructuralDesignAssessment(SDA)andConstructionMonitoring(CM)proceduresaremandatoryforcontainershipswithabeamgreaterthan32moralengthgreaterthan150m andforothercontainershipsofabnormalhullform,orofunusualstructuralconfigurationorcomplexity,seePt4,Ch8,1.3ofLloyd’sRegister’sRulesandRegulationsfortheClassificationofShips(hereinafterreferredtoastheRulesforShips).

1.2. Forcontainershipsotherthanthosedefinedin1.1,theSDAandCMproceduresmaybeappliedonavoluntarybasis.

1.3. TheSDAprocedurerequiresthefollowing:

Adetailedanalysisoftheship’sstructuralresponsetospecifiedloadscenariosusingfiniteelementanalysis.

Otherdirectcalculationsasapplicable.

1.4. ContainershipsaredefinedasshipswhicharededicatedtothecarriageofcontainerswithincellularguidesystemsinstalledintheholdsandtowhichtherequirementsofPt4,Ch8ofLloyd’sRegister’sRulesandRegulationsfortheClassificationofShips(hereinafterreferredtoastheRulesforShips)apply.Theseproceduresarenotintendedforapplicationtomultipurposeorhybridshipdesigns.

1.5. Thedirectcalculationoftheship’sstructuralresponseistobebasedonathree‐dimensional(3‐D)shellfiniteelementanalysiscarriedoutinaccordancewiththeprocedurescontainedintheseguidancenotes.

1.6. Thefullfiniteelement(FE)analysisprocedurecomprisesthreeparts:

PARTA: verificationofglobalstrengthusingamathematicalmodeloftheentirehull.

PARTB: verificationofstructuralcomponentsanddetails,usingfollow‐upfinemeshmodels.

PARTC: verificationofthestrengthoftransverse,sideanddoublebottomstructuresusingamathematicalmodelofthecargoholdsamidships.


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1.7. PARTCproceduresarerequiredtobecarriedoutforallcontainershipsforwhichtheShipRightSDAclassnotationisrequired.Ingeneral,thewholeofPARTCistobeapplied.TheexceptiontothisisPARTC,Ch4whichisonlyrequiredwhentheshipconfigurationdictates.

1.8. PARTAandPARTBprocedures,inadditiontoPARTCprocedures,arerequiredtobecarriedoutforcontainershipswhich:

DonotcomplyfullywithPt4,Ch8oftheRulesforShips,especiallywithregardtocross‐deckdimensions,hatchwaydeckandcoamingcornerradiiandthicknessofplateinsertsinway.

Haveabeamgreaterthan32moralengthgreaterthan290m.

Havewing‐wallsidestructureswithawidthbetweensideshellandlongitudinalbulkheadlessthan1.6m.

Incorporatefeatures,scantlingsorconstructionarrangementsthatareconsideredtobesignificantlydifferentfromnormaldesign.

1.9. AdetailedreportofthecalculationsistobesubmittedandmustincludetheinformationdetailedinSection3.ThereportmustshowcompliancewiththespecifiedstructuraldesigncriteriadetailedintherelevantPARTSofthisprocedure.

1.10. IfthecomputerprogramsemployedarenotrecognisedbyLloyd’sRegister,fullparticularsoftheprogramswillalsoberequiredtobesubmitted,seePt3,Ch1,3.1oftheRulesforShips.

1.11. Lloyd’sRegistermay,incertaincircumstances,requirethesubmissionofcomputerinputandoutputtofurtherverifytheadequacyofthecalculationscarriedout.

1.12. Wherealternativeproceduresareproposed,thesearetobeagreedwithLloyd’sRegisterbeforecommencement.

1.13. Containershipsofunusualformorstructuralarrangementsmayneedspecialconsideration,andadditionalcalculationstothosecontainedinthisproceduremayberequired.

1.14. ItisrecommendedthatthedesignerdiscussestheSDAanalysisrequirementswithLloyd’sRegisterearlyoninthedesigncycle.

Section 2: Symbols

2.1. Thesymbolsusedintheseguidancenotesaredefinedasfollows:

L = Rulelength,asdefinedinPt3,Ch1,6oftheRulesforShips

B = mouldedbreadth,asdefinedinPt3,Ch1,6oftheRulesforShips

D = depthofship,asdefinedinPt3,Ch1,6oftheRulesforShips


5

kL,k= highertensilesteelfactor,seePt3,Ch2,1oftheRulesforShips

SWBM= stillwaterbendingmoment

Mw(hog)= DesignhoggingverticalwavebendingmomentasdefinedinPt4,Ch8,16.6oftheRulesforShips.

Mw(sag) = DesignsaggingverticalwavebendingmomentasdefinedinPt4,Ch8,16.6oftheRulesforShips.

Qw+ = DesignpositiveverticalwaveshearforceasdefinedinPt4,Ch8,16.7oftheRulesforShips.

Qw‐ = DesignnegativeverticalwaveshearforceasdefinedinPt4,Ch8,16.7oftheRulesforShips.

MWC1,MWC2 = Ruledesignverticalwavebendingmoment,asdefinedinPt4,Ch8,15.3.1oftheRulesforShips

MHC1,MHC2 = Ruledesignhorizontalwavebendingmoment,asdefinedinPt4,Ch8,15.3.2oftheRulesforShips

MWTC1,MWTC2 = Ruledesignhydrodynamictorque,asdefinedinPt4,Ch8,15.3.3oftheRulesforShips

MSTC = Ruledesignstaticcargotorque,asdefinedinPt4,Ch8,15.3.4oftheRulesforShips

, = HoggingandsaggingverticalbendingmomentcorrectionfactorscalculatedinaccordancewithPt4,Ch8,16.6DesignverticalwavebendingmomentsoftheRulesforShips.

LPP = lengthbetweenperpendiculars

LCG = longitudinalcentreofgravity

TSC = scantlingdraught

g = accelerationduetogravity

ρ = densityofsea‐water

h = localheadforpressureevaluation

σo= specifiedminimumyieldstressofmaterial

σu = ultimatebucklingcapabilityofapanelofplating

Ω= bucklingfactorofsafety

σe= vonMisesorequivalentstress

= σ σ σ σ 3τ

σex= directstressinelementxdirection

σey= directstressinelementydirection


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σx = directstressinthegloballongitudinaldirection

σy = directstressmeasurednormaltothegloballongitudinaldirection

τ = shearstress

τexy= shearstressinelementx‐yplane

t = thicknessofplating

tc = thicknessdeductionforcorrosion.

2.2. Consistentunitsaretobeusedthroughouttheanalysis.

2.3. UnitsusedinallRuleequationsaretobeasdefinedintheRulesforShips.

Section 3: Directcalculationproceduresreport

3.1. AreportistobesubmittedtoLloyd’sRegisterfortheapprovaloftheprimarystructureoftheshipandistocontain:

listofplansused,includingdatesandversions;

detaileddescriptionofstructuralmodelling,includingallmodellingassumptions;

plotstodemonstratecorrectstructuralmodellingandassignedproperties;

detailsofmaterialpropertiesused;

detailsofdisplacementboundaryconditions;

detailsofallstillwateranddynamicloadingconditionsreviewedwithcalculatedshearforce(SF)andbendingmoment(BM)distributions;

detailsofthecalculationsforthewaterlinesusedforthedynamicloadingconditions;

detailsoftheaccelerationfactorsforeachloadingcondition;

detailsofappliedloadingsandconfirmationthatindividualandtotalappliedloadsarecorrect;

detailsofboundarysupportforcesandmoments;

plotsandresultsthatdemonstratethecorrectbehaviourofthestructuralmodelinresponsetotheappliedloads;

summariesandplotsofglobalandlocaldeflections;

summariesandsufficientplotsofvonMises,directionalandshearstressestodemonstratethatthedesigncriteriaarenotexceededinanymember;

bucklinganalysisandresults;


7

tabulatedresultsshowingcompliance,orotherwise,withthedesigncriteria;and

proposedamendmentstostructurewherenecessary,includingrevisedassessmentofstressesandbucklingproperties.

Part A, Chapter 1 Primary Structure of Container Ship, August 2017

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PART A:

Global Model of Complete Ship

Chapter 1:

Analysis of Global Loads


Section 2: Objectives

Section 3: Structural modelling

Section 4: Loading conditions

Section 5: Boundary conditions

Section 6: Acceptance criteria


1.1. FortheapplicationofPARTA,seeINTRODUCTION,1.8.


2.1. TheobjectivesofPARTAare

a) ToensurethattheglobalhullstressresponsewithparticularreferencetoitstorsionalcapabilitycomplieswithPt4,Ch8oftheRulesforShips.b) ToprovideboundaryconditionsforthefinemeshmodelsrequiredbyPARTBfortheinvestigationofthedetailedstressresponseofthefollowingimportantstructuraldetails:

Hatchcornerradiiattheconnectionofthecontainerholdareawiththeengineroomanddeckhousestructure,ifapplicable.

Hatchcornerradiiattheconnectionoftheupperdeckandhatchsidecoamingswiththetransversestructureofwatertightbulkheadsandopentransversebulkheads.

Scarphingandintegrationdetailsofthehatchsidecoamingswiththesuperstructureandengineroomconstruction

Hatchcornerarrangementsatfore‐endoftheship.

c)Toprovideboundaryconditionsforfinemeshmodelsofunusualstructuralarrangement.


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Section 3: Structuralmodelling

3.1. Thetorsionalresponseofacontainershipisgovernedbythestructuralarrangementsandloadingdistributionsoverthecompletelengthoftheship.Inparticular,thetorsionalstresslevelswithintheopenlengthofthehull(containerholdarea)aregreatlyinfluencedbythedegreeofwarpingconstraintprovidedbytheclosedengineroomanddeckhousestructure,ifapplicable,andtheclosedforwardandafterendsofthehull.

3.2. A3‐Dshellfiniteelementmodelofthecompleteshiplengthisrequired.Thismodelshouldextendoverthefullbreadthanddepthoftheshipandrepresent,withreasonableaccuracy,theactualgeometricshapeofthehull.Alleffectivelongitudinalmaterialistobeincluded.Similarly,alltransverseprimarystructures(i.e.watertightbulkheads,openbulkheads(mid‐holdsupportstructure),webframesandcross‐deckstructures)aretoberepresentedinthemodel.

3.3. TheFEmodelistoberepresentedusingaright‐handedCartesianco‐ordinatesystemwith:

Xmeasuredinthelongitudinaldirection,positiveforward;

Ymeasuredinthetransversedirection,positivetoportfromthecentreline;and

Zmeasuredintheverticaldirection,positiveupwardsfromthebaseline.

3.4. Thesizeandtypeofshellelementsselectedaretoprovideasatisfactoryrepresentationofthedeflectionsandstressdistributionswithintheship’sstructure.Ingeneral,theshellelementmeshistofollowtheprimarystiffeningarrangement.Hence,itisanticipatedthattherewillbe:

transversely,oneelementbetweenlongitudinalgirders;

longitudinally,oneelementbetweendoublebottomfloors;and

vertically,oneelementbetweenstringersordecks.

3.5. Forshipsinwhichanon‐standardspacingofprimarymembersisproposed,itmaybenecessarytorefinethismesharrangement,inordertoachievesatisfactoryelementaspectratios.

3.6. Theship’ssuperstructureordeckhouseistobeincludedinthemodel.Thisistoberepresentedusingshellelementswithamesharrangementsimilartothatusedforthehullinway,andwhichadequatelyrepresentthestructuralarrangementofthedeckhouse.However,fordeckhousetiershigherthantheseconddeckabovethelevelofthehatchcoamings,acoarsermeshidealisationmaybeused.

3.7. Theproposedscantlings,excludingOwner’sextrasandanyadditionalthicknessesfittedtocomplywiththeoptionalShipRightEnhancedScantlingsdescriptivenote,ES,aretobeincorporatedinthemodel.Allprimarystructureistoberepresentedbyplateelements.Thisincludesthedeckplating,bottomandsideshellplating,longitudinalgirders,longitudinalandtransversebulkheadplating,transversefloors,sidewebplating,stringerplates,etc.

3.8. Secondarystiffeningmembersmaybemodelledusinglineelements,groupedatplateboundaries,positionedintheplaneoftheplatinghavinganaxialproperty.Whereappropriate,asinglelineelementmayrepresentmorethanonesecondarystiffener.Thelineelementsaretohaveacross‐sectionalarearepresentingthestiffenerarea.

3.9. Faceplateandplatepanelstiffenersofprimarymembersmayberepresentedbylineelementshavinganaxialproperty.


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3.10. Figs.1.3.1to1.3.5indicateacceptablemesharrangementsforthevariousstructuralcomponentsofatypicalgirderlesscontainership.

3.11. Themodelling,loadcasesandboundaryconditionsofPARTAarebasedontheassumptionofafull‐breadthmodel.

3.12. Ifthedesignerdoesnothavesufficientresourcestoundertakeafull‐breadthFEanalysis,thenahalf‐breadthshipmodel,usingasymmetricloadingtechniques,isacceptable.


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Fig.1.3.1

3‐Dfiniteelem

entm

odelofcom

pletecontainership

Fig.1.3.2

3‐Dfiniteelem

entm

odelshow

ingtheportsideoftheship


12

Fig.1.3.3

TypicalFEmodelofatransversewebframe

Fig.1.3.4

TypicalFEmodelofanopenbulkheadframe


13

Fig.1.3.5

TypicalFEmodelofawatertightorclosedbulkheadframe

Section 4: Loadingconditions

4.1. Anumberofstandardloadcasesaretobeconsidered.ThepurposeoftheseloadcasesistoensurethatthelongitudinalstrengthofthehullstructurecomplieswiththeloadingcombinationsspecifiedinPt4,Ch8oftheRulesforShips.

4.2. WhererequiredbyPt4,Ch8,14.1.2oftheRulesforShips,non‐linearshipmotionanalysisistobeusedtocalculatethevertical,horizontalandtorsionalloadsinobliqueseaconditions.Thesevertical,horizontalandtorsionalloadsobtainedaretobeusedfortheanalysisinPARTAandPARTB.GuidancefortheapplicationofthedirectcalculatedloadsisdescribedinAppendixB.

4.3. ThesignconventionsadoptedfortheanalysisinPARTAandPARTBareshowninFig.1.4.1.Loadcasesrepresentingthefollowingloadcomponentsarerequiredtobeanalysedfortheconstructionofthecombinedloadcases:

4.3.1. Hoggingstillwaterbendingmoment Aspecialloadcaseistobepreparedwhichfulfilsthefollowingcriteria:

Shiptobeuprightatorneartothescantlingdraught.

Allbaysaretobefilledwithcontainers.

Fueloildeeptanksconstructedintransversebulkheadstructuresorfueloildeeptanksconstructedincontainercargohold,wherefitted,aretobefilled.


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Aconditionwhichresultsinthestillwaterbendingmomentdistributionappliedtothemodelbeingapproximatelythesameastheassigned,orspecified,permissiblehoggingstillwaterbendingmomentdistribution.Themaximumpermissiblestillwaterbendingmomentwithin0.4Lamidshipsistobeachieved.

IncrementalverticalforcesmaybeappliedtothesideshelloftheFEmodelforadjustingthebendingmomenttomeettherequireddistributionalongtheshiplength.Alternatively,thestressesmaybeadjustedusingthemethoddescribedin6.4.

4.3.2. Saggingstillwaterbendingmoment Aspecialloadcaseistobepreparedwhichfulfilsthefollowingcriteria:

Shiptobeuprightatlightdraughtwhichresultsinamaximumsaggingorminimumhoggingstillwaterbendingmoment.

Fueloildeeptanksconstructedintransversebulkheadstructuresorfueloildeeptanksconstructedincontainercargohold,wherefitted,aretobefilled.

Allbaysaretobefilledwithcontainers.

Aconditionwhichresultsinthestillwaterbendingmomentdistributionappliedtothemodelbeingapproximatelythesameastheassigned,orspecified,permissiblesaggingorminimumhoggingstillwaterbendingmomentdistribution.Themaximumpermissiblesaggingorminimumhoggingstillwaterbendingmomentwithin0.4Lamidshipsistobeachieved.

IncrementalverticalforcesmaybeappliedtothesideshelloftheFEmodelforadjustingthebendingmomenttomeettherequireddistributionalongtheshiplength.Alternatively,thestressesmaybeadjustedusingthemethoddescribedin6.4.

4.3.3. Headsea(Hog)Thisloadcaseisintendedtorepresentthedesignhoggingverticalbendingcondition. Thisistocomprisethefollowing:

a) Thehoggingstillwaterloadcaseasspecifiedin4.3.1.

b) Adistributionofforcesorpressureswhichinducethehoggingdesignverticalwavebendingmoment,Mw(hog)asdefinedin2.1ofINTRODUCTION,alongthemodellength.Therequiredwavebendingmomentmaybegeneratedbyuseofahoggingwavewiththefollowingcharacteristics:

awavelengthequaltoLPP;

thewavecrestamidships;

asinusoidalwaveprofile;and

aheightsufficienttoinducetherequiredhoggingdesignverticalwavebendingmoment(VWBM)amidships.

Thewaveheightrequiredtoinducetherequiredbendingmomentwillneedtobederivedbytrialanderrorusingasuitablestillwaterloadsprogram.Theshipistobebalancedonthewaveandtheresultingdraft,trimandwaveparametersaretobeusedfordeterminationoftheexternalpressuredistribution.Thewavebendingmomentachievedinthemodelusingthistechniquewillonlybecorrectatthemidshiplocation.Hence,itwillbenecessarytoadjusttheverticalbendingtomeettherequireddistributionalongtheshiplength.ThismaybeachievedbyapplyingincrementalverticalforcestothesideshelloftheFEmodel.Alternately,asindicatedin6.4,thelongitudinalstressresultsateachframelocationmaybe


15

factoredpriortocomparingwiththeacceptancecriteria.Alternativemethodsofgeneratingthewavebendingmomentdistributionwillbeconsidered.

4.3.4. Headsea(Sag)Thisloadcaseisintendedtorepresentthedesignsaggingverticalbendingcondition. Thisistocomprisethefollowing:

a) Thesagging(orminimumhogging)stillwaterloadcaseasspecifiedin4.3.2.

b) Adistributionofforcesorpressureswhichinducethesaggingdesignverticalwavebendingmoment,Mw(sag)asdefinedin2.1ofINTRODUCTION,alongthemodellength.Therequiredwavebendingmomentmaybegeneratedbyuseofasaggingwavewiththefollowingcharacteristics:

awavelengthequaltoLPP;

thewavetroughamidships;

asinusoidalwaveprofile;and

aheightsufficienttoinducetherequiredsaggingdesignverticalwavebendingmoment(VWBM)amidships.

Thewaveheightrequiredtoinducetherequiredbendingmomentwillneedtobederivedbyatrialanderrorproceduredescribedin4.3.3.

4.3.5. Headseaverticalwavebendingmoment(Mw(hog))The ship is subjected only to wave pressure loads which generate the hogging design vertical wavebendingmoment,Mw(hog) asdefined in2.1of INTRODUCTION, along themodel length.This load casemay be constructed by subtracting the stillwater load case (4.3.1) from the head sea (hog) load case(4.3.3).ThisloadcaseisusedforPARTB’sanalysisonly.

4.3.6. Headseaverticalwavebendingmoment(Mw(sag))Theshipissubjectedonlytowavepressureloadswhichgeneratethesaggingdesignverticalwavebendingmoment,Mw(sag)asdefinedin2.1ofINTRODUCTION,alongthemodellength.Thisloadcasemaybeconstructedbysubtractingthestillwaterloadcase(4.3.2)fromtheheadsea(sag)loadcase(4.3.4).ThisloadcaseisusedforPARTB’sanalysisonly.

4.3.7. Obliqueseaverticalwavebendingmoments(MVWi)TheverticalwavebendingmomentloadcasesspecifiedinAppendixCarerequired.Theshipissubjectedonly to the vertical wave bending moments which generate the required vertical wave bendingdistributions.

4.3.8. Obliqueseahydrodynamictorques(MTWi) ThehydrodynamictorqueloadcasesspecifiedinAppendixCarerequired.Theshipissubjectedtopuretorsionalmomentswhichgeneratetherequiredhydrodynamictorquedistributions.

4.3.9. Cargotorque(MSTC)TheshipissubjectedtopuretorsionalmomentswhichgeneratetheRulecargotorquedistributiongiveninPt4,Ch8,15.3.4oftheRulesforShips,orthespecifiedcargotorque,ifthisislarger.

4.3.10. Obliqueseahorizontalwavebendingmoments(MHWi)The horizontalwave bendingmoment load cases as specified in Appendix C are required. The ship issubjected to pure bending moments which generate the required horizontal bending momentdistributions.


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4.3.11. Longitudinal(surge)accelerationThefollowingInertialoadsduetolongitudinalaccelerationaretobeconsidered:

Containers:Longitudinalcomponentofcontainerloads,arisingfromtheeffectofshipmotions,actingonthetransversebulkheadsandcrossdeckstructure.SeePARTC,Ch2,fordefinitionofthisloadcomponent.

FuelOil(orotherliquids):Longitudinalcomponentoffueloil(orotherliquid)loads,arisingfromtheeffectofshipmotions,actingonthetransversebulkheads.Iftheshipcarriesfueloil(orotherliquids)indeeptanksconstructedinthetransversebulkheadstructuresordeeptankswithinthecontainercargoholdsthentheseadditionalloadcomponentsarerequiredtobeincludedintheanalysisofthesestructures.Similarly,ifanalysingthearrangementsforwardandaftoftheengineroomforashipwhichcarriesfueloil(orotherliquids)indeeptanksconstructedwithinthecontainercargoholdsimmediatelyaftorforwardoftheengineroom,thentheseadditionalloadcomponentsarerequiredtobeincludedintheanalysis.HydrostaticloadingisalsotobeincludedifthiscomponentwasomittedfromthestillwaterloadcaseofPARTA.SeePARTC,Ch5fordefinitionofthisloadcomponent.

Thislongitudinalloadisrequiredfortheassessmentofcrossdeckboxandtransversebulkheadstructures,seeTable1.6.1,andPARTB’sanalysis.

4.4. Inconstructingtheloadcasesreferredtoin4.3,theloadcomponentsgiveninTable1.4.1aretobeincluded.Alternativemethodsofachievingtheloadcasesdescribedin4.3willbeconsidered.

4.5. Forahalf‐breadthmodel,onlytheloadsapplicabletoonehalfofthemodelaretobeapplied.Theseloadsaretobederivedinthesamemannerasthatrequiredforafull‐breadthmodel.


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NOTES

1. Verticalbendingmoment–hoggingverticalbendingmomentispositiveandproducestensilestressesatthedeck.

2. Horizontalbendingmoment‐positivehorizontalbendingmomentproducestensilestressesatstarboardsideoftheship.

3. Hydrodynamicandcargotorquesaretobeappliedsothatthewarpingstressesontheportsidedeckinwayoftheengineroomareincompression,seeFig.1.4.2.

Fig.1.4.1

ThesignconventionsadoptedfortheanalysisinPARTAandPART


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InphasehydrodynamictorqueMTW1

OutofphasehydrodynamictorqueMTW6

Fig.1.4.2

Applicationofincrementaltorsionalmomentstogeneratehydrodynamictorquedistributions

NOTE:Theinphaseandoutofphasehydrodynamictorquedistributions, and ,giveninAppendixC,arethesamedistributionsas and inPt4,Ch8,15.3.3oftheRulesforShips.


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Table1.4.1 SummaryofloadcomponentsforthefullshipFEmodel

Loadcase Loadcomponent Remarks

Hoggingstillwater

See4.3.1

Saggingstillwater

See4.3.2

Headsea(Hog)

See4.3.3

Headsea(Sag)

See4.3.4

Steelweight

Asgeneratedfromthemodelledhullstructure,suitablyfactoredtoachievethespecifiedsteelweight,includingthepositionoftheLCG.Inthisrespect,itmaybeusefultodividethemodellongitudinallyintoanumberofmaterialzones,eachofwhichcanhaveaseparatefactoredvalueforthesteeldensity.

MachineryandoutfitAllmajoritemstobeappliedaspointloadsorpressureloadsattheircorrectlocations.Minororunknownitemsmaybeincludedinthesteelweight.

Containersabovedeck(onhatches)

Verticalloadstobeappliedtothehatchcoamingsofcross‐deckstructureinwayofthestackcorners.

Containersinholdsandabovedeckinopenhatch(hatchcoverless)ships

Verticalloadstobeappliedtolongitudinalstructureatthestackbase.

Buoyancyloads

Tobeappliedaspressureloads,ρgh,onwettedshellelements,wherehisthedistanceoftheelementcentroidbelowthestillwaterlineorwaveprofileasappropriate.

Additionalforcesorpressures

Asnecessarytoachievetherequiredstillwaterandwavebendingmomentdistributions.

BallastandfueloilTobeappliedaspressureloadsornodalforcesontankboundaries,basedontheactualliquidhead.Anyover‐pressurisationofthetankistobeomitted.

Headseaverticalwavebendingmoment(Mw(hog))See4.3.5

Hoggingdesignverticalwavebendingmomentdistribution,asdefinedin2.1ofINTRODUCTION.

Combinedloadcaseasfollows:Headsea(Hog)–Hoggingstillwater

Headseaverticalwavebendingmoment(Mw(sag))See4.3.6

Saggingdesignverticalwavebendingmomentdistribution,asdefinedin2.1ofINTRODUCTION.

Combinedloadcaseasfollows:Headsea(Sag)–Saggingorminimumhoggingstillwater

Obliqueseaverticalwavebendingmoment(MVWi)See4.3.7

Verticalwavebendingmoment,MVWi,asspecifiedinAppendixC

Incrementalverticalforcesaretobeappliedtothesideshell(portandstarboard)ateachframepositiontogeneratetherequiredverticalwavebendingmomentdistribution.Nootherloadcomponentsaretobeincluded.

Obliqueseahydrodynamictorque(MTWi)See4.3.8

Hydrodynamictorquedistribution,MTWi,asspecifiedinAppendixC

Incrementaltorsionalmomentsaretobeappliedalongthelengthoftheshipasforcesactingintheplaneofthesideshell.Whenintegratedalongtheshiplength,theincrementaltorsionalmomentsaretogeneratetheRulehydrodynamictorquedistribution.Nootherloadcomponentsaretobeincluded.

Cargotorque(MSTC)See4.3.9

Cargotorquedistribution,MSTC,asgiveninPt4,Ch8,15.3.4oftheRulesforShips

Incrementaltorsionalmomentsaretobeappliedalongthelengthoftheshipasforcesactingintheplaneofthesideshell.Whenintegratedalongtheshiplength,theincrementaltorsionalmomentsaretogeneratetheRulecargotorquedistribution.Nootherloadcomponentsaretobeincluded.

Obliqueseahorizontalwavebendingmoment(MHWi)See4.3.10

Horizontalwavebendingmomentdistribution,MHWi,asspecifiedinAppendixC

Incrementallongitudinalforcesaretobeappliedtothesideshellportandstarboardatthebulkheadpositionstogenerateamomentcoupleateachbulkhead.Whenintegratedalongtheshiplength,theincrementalmomentcouplesaretogeneratetheRulehorizontalwavebendingmomentdistribution.Nootherloadcomponentsaretobeincluded.


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4.6. ThefollowingloadcasesaretobecomparedwiththeassessmentcriteriaspecifiedinSection6:

Headsealoadcases(seeTable1.4.2);

Obliquesealoadcases(seeTable1.4.3).Alternatively,thestresscombinationsgiveninAppendixDmaybeusedtoobtainthemaximumandminimumlongitudinaldirectstressesifthehydrodynamicloadsspecifiedinAppendixCareapplied.However,ifnon‐linearshipmotionanalysisisusedtodeterminethehydrodynamicloads,see4.2,theloadcombinationsgiveninTable1.4.3mustbeused.

Table1.4.2 Loadcombinationsforheadseacondition

Loadcase Wavedirection WaveStillwaterloadcase

(seeNote4)

LongitudinalAcceleration,seeNote1

(Containers,seeNote2

and/orFO,seeNote3)

Stillwaterhoggingcondition

H1a HeadSea Hog 1(seeNote5)H1b(seeNote6) HeadSea Hog 1(seeNote5)

H2a HeadSea Hog ‐1(seeNote5)H2b(seeNote6) HeadSea Hog ‐1(seeNote5)

Stillwatersaggingcondition

H3a HeadSea Sag 1(seeNote5)H3b(seeNote6) HeadSea Sag 1(seeNote5)

H4a HeadSea Sag ‐1(seeNote5)H4b(seeNote6) HeadSea Sag ‐1(seeNote5)

Symbols

Stillwater(Hog) Stillwaterloadcasewithrequiredhoggingpermissiblestillwaterbendingmomentasdescribedin4.3.1.

Stillwater(Sag)Stillwaterloadcasewithrequiredsaggingorminimumhoggingpermissiblestillwaterbendingmomentasdescribedin4.3.2.

(hog) HeadSeahoggingverticalwavebendingmoment(Mw(hog))loadcaseasdescribedin4.3.5.Notethatthehoggingverticalbendingmomentistobeinaccordancewiththatspecifiedin2.1ofINTRODUCTION.

(sag) HeadSeasaggingverticalwavebendingmoment(Mw(sag))loadcaseasdescribedin4.3.6.Notethatthesaggingverticalbendingmomentistobeinaccordancewiththatspecifiedin2.1ofINTRODUCTION.

NOTES1. Longitudinalaccelerationloadcomponentisrequiredtobeappliedin theassessmentoftransversebulkheadandcrossdeck

structures,seeTable1.6.1,andtheanalysisinPARTB.2. Containers‐longitudinalcomponentofcontainerloads,arisingfromtheeffectofshipmotions,actingonthetransverse

bulkheadsandcrossdeckstructure.See4.1andPARTC,Ch2,fordefinitionofthisloadcomponent.3. FO‐longitudinalcomponentoffueloil(orotherliquid)loads,arisingfromtheeffectofshipmotions,actingonthetransverse

bulkheads.See4.1andPARTC,Ch5,fordefinitionofthisloadcomponent.4. Hoggingandsagging(orminimumhogging)stillwaterloadcasesasspecifiedin4.3.1and4.3.2aretobeconsidered.5. Inertiaforceduetolongitudinalaccelerationofcontainersand/orfueloil,see4.3.11.

1:applicationofheadseapositivepitchaccelerationcaseMC1(HS_1)‐1:applicationofheadseanegativepitchaccelerationcaseMC1(HS_2)

6. ThiscaseisonlyrequiredforPARTB’sanalysis.


21

Table1.4.3 Loadcombinationsforobliqueseacondition

Loadcase Wavedirection

LoadCombination(atstepi)

ID

Wave Static

Containerand/orFO

(seeNotes6&7)

Stillwaterloadcase(seeNote4)

(seeNote5)

Stillwaterhogging

OS1

Starboard

OS1i 1 1 1 1 Hog 1

OS2 OS2i 1 1 1 1 Hog ‐1

OS3 OS3i 1 1 1 ‐1 Hog 1

OS4 OS4i 1 1 1 ‐1 Hog ‐1

OP1

Port

OP1i 1 ‐1 ‐1 1 Hog 1

OP2 OP2i 1 ‐1 ‐1 1 Hog ‐1

OP3 OP3i 1 ‐1 ‐1 ‐1 Hog 1

OP4 OP4i 1 ‐1 ‐1 ‐1 Hog ‐1

Stillwatersagging

OS5

Starboard

OS5i 1 1 1 1 Sag 1

OS6 OS6i 1 1 1 1 Sag ‐1

OS7 OS7i 1 1 1 ‐1 Sag 1

OS8 OS8i 1 1 1 ‐1 Sag ‐1

OP5

Port

OP5i 1 ‐1 ‐1 1 Sag 1

OP6 OP6i 1 ‐1 ‐1 1 Sag ‐1

OP7 OP7i 1 ‐1 ‐1 ‐1 Sag 1

OP8 OP8i 1 ‐1 ‐1 ‐1 Sag ‐1

NOTES1. Themaximumandminimumdirect(tangential)stressesoveracompletewavecycle(i.e.forallstepsi)areobtainedas

followsforcomparisonagainsttheacceptancecriteria:σ OSna Max σ OSn σ OSnb Min σ OSn σ OPna Max σ OPn σ OPnb Min σ OPn where, 1, 2, 3, 4, 5, 6, 7and8

2. TheelementvonMisesstressistobecalculatedindividuallyateachstepusingthecorrespondingdirectandshearstressesatthesamestep.ThemaximumvonMisesstressesoveracompletewavecycle(i.e.forallstepsi)areobtainedasfollowsforcomparisonagainsttheacceptancecriteria:σ OSn Max σ OSn σ OPn Max σ OPn where, 1, 2, 3, 4, 5, 6, 7and8

3. Thebucklingfactorofsafetyistobecalculatedindividuallyateachstepusingthecorrespondingdirectandshearstressesatthesamestep.Theminimumbucklingfactorofsafetyoveracompletewavecycle(i.e.forallstepsi)aretobelessthantherequiredcriteria:λ OSn Min λ OSn λ OPn Min λ OPn where, 1, 2, 3, 4, 5, 6, 7and8

4. Hoggingandsagging(orminimumhogging)stillwaterloadcasesasspecifiedin4.3.1and4.3.2aretobeconsidered.Thestressofeachstillwaterloadcaseistobecombinedwiththestressesduetocargotorqueandwaveloads(includinglongitudinalaccelerationinertialoadwhererequired,seeNote6forassessingagainsttheacceptancecriteria).

5. Cargotorqueloadcase,see4.3.9.

6. Longitudinalaccelerationloadcomponentisrequiredtobeappliedfortheassessmentoftransversebulkheadandcrossdeckstructures,seeTable1.6.1,andPARTB’sanalysis.

7. Inertialforceduetolongitudinalaccelerationofcontainersand/orfueloil,see4.3.11. 1indicatesapplicationofobliqueseapositivepitchaccelerationcaseMC3(OS1_1) ‐1indicatesapplicationofobliqueseanegativepitchaccelerationcaseMC3(OS1_2)Forcontainers,seePARTC,Ch2,fordefinitionofthisloadcomponent.ForFO,seePARTC,Ch5,fordefinitionofthisloadcomponent.


22

Section 5: Boundaryconditions

5.1. Theloadcasesspecifiedin4.3requiredifferentboundaryconditionsasgiveninTable1.5.1.TheseboundaryconditionsareillustratedinFig.1.5.1.

5.2. TheboundaryconditionsspecifiedinTable1.5.2combinedwiththoseinTable1.5.1areappropriateforahalf‐breadthmodel

5.3. Theboundaryconditionsdescribedinthissectionarepreferred.However,alternativeequivalentboundaryconditionsmaybeused.

5.4. InTable1.5.1,‘openlength’referstothecontainerholdareaoftheshipwhichliesforwardofthe‘closed’engineroomsection.

Table1.5.1 Boundaryconditionsforafull‐breadthmodel

LoadcaseSee

Paragraph Boundaryconditions

Hoggingstillwater

Saggingstillwater

Headsea(Hog)

Headsea(Sag)

Obliqueseaverticalwavebendingmoments

4.3.14.3.2

4.3.34.3.4

4.3.7

(a)Themodelistobefreeofimposedconstraints,exceptforthosenecessarytopreventrigidbodymotion.Rigidbodymotionsmaybepreventedbytheuseoffree‐bodyconstraints(e.g.theInertiaRelieffacilityinNastranterminology).

(b)Alternatively,modelmaybeconstrainedasfollows:

AttheF.P.onthecentreline:δy=δz=0

AttheA.P.onthecentreline:δx=δy=δz=0

AtthedeckonthecentrelineattheAP:

δy=0

(c) SeeNotes1and3.

Hydrodynamictorques

Cargotorque

4.3.8

4.3.9

(a)Atabulkheadneartomid‐lengthoftheopenlength:

•verticalconstraint(δz=0)atthesideshellatmid‐depth,portandstarboard

•longitudinalconstraint(δx=0)atthekeelonthecentreline

•transverseconstraint(δy=0)atthekeelonthecentreline.

(b)Attheaftendofthekeelortransom,whereappropriate,andattheforwardendofthekeelonthecentreline:

•groundedvertical(Z)springs,seeNote2.(c) AtthedeckneartheF.P.andA.P.onthecentreline:

•groundedtransverse(Y)springs,seeNote2.(d)SeeNote1.

Horizontalwavebendingmoments

4.3.10

(a)Atabulkheadneartomid‐lengthoftheopenlength:

• verticalconstraint(δz=0)atthekeelonthecentreline

•longitudinalconstraint(δx=0)atthedeckedge,portandstarboard

• transverseconstraint(δy=0)atthedeckandkeelonthecentreline.

(b)Attheaftendofthekeelortransom,whereappropriate,andattheforwardendofthekeelonthecentreline:

• groundedvertical(Z)springs,seeNote2.

(c) SeeNote1.

NOTES1. Careistobetakentoensurethat,withinpracticablelimits,thereisnonetimbalanceofloadormomentinanyofthesix

degreesoffreedom.2. Springstiffnessistobesmall,equivalentto1kgf/m.Theresultantloadinthespringsistobecheckedtoensuretheseloads

arenotsignificant.3. CareistobetakentoensurethattheFEmodelisnotoverconstrained.


23

Table1.5.2 Additionalboundaryconditionsforahalf‐breadthmodel

LoadcaseSee

ParagraphBoundaryconditions

Stillwater

Headsea

Obliqueseaverticalwavebendingmoments

4.3.1and4.3.2

4.3.3and4.3.4

4.3.7

Centrelineplane:Symmetryconstraints,i.e.δy=θx=θz=0

Hydrodynamictorque

Cargotorque

4.3.8

4.3.9Centrelineplane:Anti‐symmetryconstraints,i.e.δx=δz =θy=0

Horizontalwavebendingmoment 4.3.10 Centrelineplane:Anti‐symmetryconstraints,i.e.δx=δz =θy=0

NOTE

TheseboundaryconditionsareadditionaltothosegiveninTable1.5.1andtakeprecedenceovertherequirementsofTable1.5.1whennecessary.


24

(1) Still water, head sea and oblique sea cases

Fig.1.5.1

BoundaryconditionsfortheglobalshipFEmodel:locationsoffreebodyconstraints

Section 6: Acceptancecriteria

6.1. InaccordancewiththeproceduressetoutinPt4,Ch8oftheRulesforShips,thelongitudinaldirectstressvaluesalongthecompleteshiplengtharenottobegreaterthanthevaluesindicatedinTable1.6.1atthefollowingpositions:

a) theinboardedgeofthestrengthdeck;

b) thepointonthebilgewherethecombinedstressisgreatest;and

c) thetopofcontinuoushatchcoaming.


25

6.2. Atthehatchsidecoamingandupperdeckintersections,stressconcentrationsarisefromtheinter‐connectionofthesuperstructure/closedengineroomsectionandthecross‐deckstrips.Theseareasaretobesubjecttothefollow‐upanalysesindicatedinPARTB.

6.3. ThestressesinthetransversebulkheadandcrossdeckstructuresarenottobegreaterthanthevaluesindicatedinTable1.6.1

6.4. ThedistributionofactualSWBM,Mw(hog)andMw(sag),obtainedoverthelengthofthemodelaretobecomparedwiththerequiredbendingmomentdistributions.ThelongitudinalstressvaluederivedfromtheFEmodelforeachlongitudinallocationistobefactoredbytheratioofthelocallyrequiredbendingmomenttothelocallyachievedmomentpriortocombiningwithstressesfromotherloadcases,forcomparisonwiththeacceptancecriteriaspecifiedinTable1.6.1.

6.5. Figuresshowingtheresultinglongitudinalstressdistributionsaretobeproduced.AnexamplestressdistributionplotisshowninFig.1.6.1.

6.6. Structuresinwayofhighstressgradientsaretobesubjecttofurtherinvestigation.

6.7. ThebucklingstrengthofthelongitudinalandtransversemembersasindicatedinTable1.6.1istobeinvestigatedusingtheproceduredescribedinShipRightADP(AdditionalDesignandConstructionProcedures)–GuidanceNotesforShipRightSDABucklingAssessment.AminimumfactorofsafetyasgiveninTable1.6.1istobeachieved.

6.8. ThebucklingcapabilityofhullstructuresistobeassessedusingaplatethicknessreducedbythestandardthicknessdeductionvaluesgiveninPARTC,Ch1,Table1.6.2.

6.9. SubjecttoLloyd’sRegister’sagreement,alternativemethodsforbucklingassessmentsmaybespeciallyconsidered.


26

Table1.6.1 Maximumpermissiblemembranestresses

Maximumpermissiblemembranestresses(N/mm2)

SeeNote1 MinimumBucklingFactorofSafety

ΩLoadcase Structuralitem Von‐MisesstressDirectstress

(SeeNote2)Shearstress

Headsea(Hog)See4.3.3Headsea(Sag)See4.3.4

LongitudinalhatchcoamingUpperdeckplating

‐ 0,745σL ‐ ‐

BottomshellTurnofbilgeInnerbottom

‐ 0,92σL ‐1,2

SeeNote5

Crossdeckbox(SeeNote3) 0,750 ‐ ‐ 1,2

Longitudinalstructuralmemberselsewhere

‐ 0,745σL ‐1,2

SeeNote5

Obliquesea

See6.4

Longitudinalhatchcoaming ‐ 0,745σL ‐ 1,2

Upperdeckplating ‐ 0,67σL ‐ 1,2

BottomshellTurnofbilgeInnerbottom

‐ 0,845σL ‐ 1,2

Crossdeckbox(SeeNote3) 0,750 ‐ ‐ 1,2

Transversebulkheadstructure(SeeNote3) 0,750 ‐ 0,350 1,2

Longitudinalstructuralmemberselsewhere(SeeNote6)

‐ 0,67σL ‐ 1,2

where

σL=235/kLN/mm2

NOTES

1. Seealso6.4.2. Themagnitudeofthedirectstressistobelessthanthepermissiblevalue.3. Fortheassessmentofcrossdeckboxandtransversebulkheadstructure,inertialloadsduetolongitudinalaccelerationare

tobeconsidered,see4.3.11.4. See4.6forloadcasesforassessment5. Thebucklingstrengthofthelongitudinalmembers,outsidetheextentcoveredorassessedbyPARTC,aretobe

investigated.6. Includingplatformsinengineroomthatareconsideredtobeeffectivelongitudinalstrengthmembers.


27

Fig.1.6.1

Longitudinaldistributionofstressinahatchsidecoam

ing(Forillustrativepurposes)

Part B, Chapter 1 Primary Structure of Container Ship, August 2017

28

PART B:

Verification of Structural Components and

Details

Chapter 1:

Analysis of Global Loads on Local Details




Section 4: Loading and boundary conditions



1.1. FortheapplicationofPARTB,seeINTRODUCTION,1.8.


2.1. TheobjectiveofPARTBistoensurethatthestructuralresponsesofthefollowingstructuraldetailsarewithinacceptablelimits:

a) Hatchcornerradiiattheconnectionofthecontainerholdareawiththeengineroomanddeckhousestructure,ifapplicable(see3.4and3.5).

b) Hatchcornerradiiattheconnectionofthelowerdecks,upperdeckandhatchsidecoamingswiththetransversestructureofthewatertightbulkheadsandopentransversebulkheads(see3.3).

c) Forcontainershipswithfueloildeeptankslocatedinboardoftheinnerskinandabovethedoublebottom:thearrangementsoftheconnectionofthecrownofthefueloildeeptankstothesidestructure(see3.7).

d) Scarphingandintegrationdetailsofthehatchsidecoamingswiththesuperstructureandengineroomconstruction(see3.4and3.5).

e) Connectionoftheforwardopenlengthwiththeforwardendoftheship(see3.6).

f) StructureinwayofhighstressgradientsorareasexceedingthestresscriteriaspecifiedinPARTA.

g) Anyotherunusualfeature.


29


3.1. Thestructuraldetailsspecifiedin2.1aretoberepresentedbyfinemeshinthePARTAglobalmodel.Alternatively,separatedetailedfinemeshmodelscoveringthestructuraldetailsaretobepreparedandloadedwithenforceddisplacementsobtainedfromthefullshipglobalanalysis.

3.2. Finemeshmodelswillberequiredfortheareasdetailedbelow.TypicalmodelsareindicatedinFigs.1.3.1and1.3.2.

3.3. Midshipcross‐deckstripandhatchcornerdetail

3.3.1. A model of the midship cross‐deck strip at approximately the position of maximum warpingdisplacement.AtypicalmodelisshowninFig.1.3.1andmodellingguidanceisgivenin3.8.

3.3.2. Ifthescantlingsand/orstructuralarrangementofthehatchcornercross‐deckstructureandthehatch coaming arrangement differ between the watertight bulkheads and the open bulkheads, thenmodelsofbothbulkheadarrangementswillberequired.Similarly,iftherearedifferentbulkheaddesignarrangements,thenamodelistobemadeofeachdesignvariant.

3.3.3. For container ships with fuel oil deep tanks arranged between the inner skin and above thedoublebottom,afinemeshmodeloftheconnectionofthecross‐deckarrangementstothesidestructurewillberequiredinwayofthehatchcoamingandupperdecklevelsandalsoatthetankcrownlevel.Thismodelisadditionaltothatdescribedin3.3.1and3.3.2.

3.4. Connectionoftheforwardopenlengthwiththeforwardendoftheengineroom

3.4.1. A model of the integration of the open length with the forward end of the engine roomencompassing the hatchway radius at upper deck level, the hatch corner radius at hatch coaming topleveland,ifapplicable,theintegrationofthehatchsidecoamingswiththesuperstructureside.AtypicalmodelisshowninFig.1.3.2andmodellingguidanceisgivenin3.8.

3.4.2. Themodeldescriptionhasbeenframedonthebasisthatthelongitudinalhatchsidecoamingsareintegratedwith the superstructure. If, however, a separate deckhouse is proposedwith discontinuoushatch side coamings, then the model should permit examination, using a suitable fine mesh, of thediscontinuitiesintroducedbysuchanarrangement.

3.5. Connectionoftheaftopenlengthwiththeaftendoftheengineroom

3.5.1. A model of the integration of the aft open length with the engine room/superstructurearrangement,similartothatdescribedin3.4,isalsotobemade.

3.5.2. Thisrequirementwillbewaivedifthescantlingsandarrangementsoftheaftintegrationarethesame as the forward integration and the stress levels, obtained from PART A, of the full ship globalanalysesarelower.

3.6. Connectionoftheforwardopenlengthwiththeforwardendoftheship

3.6.1. Amodeloftheintegrationoftheforwardopenlengthwiththefore‐shipisalsotobemade.

3.6.2. TheextentandpositionofthismodelistobedecidedonreviewofthePARTAresults.Agreementofthelocalplanapprovalofficetothemodellingproposalsshouldbeobtainedpriortocommencingtheanalysis.Generalmodellingguidanceisgivenin3.8.

3.7. Connectionofopenlengthswithfueloildeeptanksconstructedwithincontainerhold


30

3.7.1. In caseswhere fuel oil deep tanks are arranged inboard of the inner skin and above the innerbottomandhavelengthexceedingfourtimesthewidthofthecross‐deckstripspecifiedinPt4,Ch8,4.3.1oftheRulesforShips,analysisoftheintegrationwiththeadjacenthullstructureistobecarriedout.

3.7.2. Themodelsaretobeasdescribedin3.4,3.5,3.6and3.8.

3.7.3. If the crownof the fuel oil tank is not in linewith the coaming top or upper deck, the verticalextentofthemodelistobeincreasedsothatthemodelextendsfromonestringerlevelbelowthecrownof the tank to the coaming top. The corner arrangements in adjacent container holds in linewith thecrownof the tankare tobemodelled in finemeshand resultsare to complywith the requirementsofSec5.

3.8. ModellingRequirements

3.8.1. Thesemodelsaretoincludeafinemeshinwayofthehatchcornerradiiattheupperandlowerdecksandhatchcoamingtoplevels.Similarly,asuitablyfinemeshistobeincludedatthescarphingandintegrationdetailsofthehatchsidecoamingswiththesuperstructureandengineroomconstructions.

3.8.2. The levelof refinement is tobe suchas toenable stress concentrations tobe identified.Wherefiniteelementanalysisprogramsdonotsupplynodalstresses,alineelementofsmall(nominal)areaistobeincorporatedtoobtainthepeakedgestressesatthefollowinglocations:

alongtheplateedgeofhatchcornersatthelowerdecks,upperdeckandhatchcoaming,

alongthesuperstructuretohatchsidecoamingscarphingbrackets.

3.8.3. Theextentof thesemodels is tobesuch that theapplicationofboundarydisplacements (takenfromtheglobalanalysis)willnotaffecttheresponseattherelevantpointsofthelocalfinemeshmodel. Ingeneral,itisrecommendedthatthemodelextends:

transverselyoverthehalf‐breadthoftheship,

longitudinallyfromthemidpointofone40ftcontainerbaytothemidpointofthenext40ftcontainerbay,

verticallyfromthecoamingtopplatetothedeckorstringersbelowtheintersectionofthebottomofthecross‐deckstripwiththelongitudinalbulkhead.

3.8.4. In respectof themodeldescribed in 3.4 and3.5, a similar extent shouldbe used, butwith theverticalextentencompassingthesuperstructuredeckabovethetopofanyscarphingbrackets.

3.8.5. Theprimary structure and coamingstays are to be representedby shell finite elementshavingbothmembraneandbendingcapability.

3.8.6. Thestructuralgeometry,particularlyinareasofconcern,istobeaccuratelyrepresented.Inthisrespect,aminimumof 15 elements in a 90 degree arc are to be used todescribe the curvature of thehatchwayradiusplating.However,theelementedgedimensionsalongthefreeedgeoftheradiusshouldnotbe less than the thicknessof theplatingbeing representedandalsoshouldnotbegreater than1.5times the thickness of the plating being represented. Except where necessary from practicalmeshingconsiderations,thislevelofidealisationistobemaintainedoverthebracketplatingandistoextendintothestringerplating,deckplatingandcoaming. Meshtransitionsshouldnotbearrangedclosetobrackettoes.

3.8.7. Allcut‐outs(e.g.forventilationsystems,accessopenings)aretoberepresentedinthemodel.


31

3.8.8. Secondary stiffeningmaybe represented by line elements having axial and bending properties(bars)representingthestiffenerwiththeeccentricityoftheneutralaxismodelled,except inwayoftheending of primary structure, e.g. longitudinal bulkhead longitudinal stiffener in way of cross‐deckboxbottomplating.

3.8.9. The extent of models required for 2.1(e), (f) and (g) will be subject to special consideration.However,themodellingphilosophyoutlinedintheprecedingparagraphswillgenerallyapply.

Fig.1.3.1

Cross‐deckstrip–Finemeshmodelshow

ingcornerdetails


32

Fig.1.3.2

Engineroom

bulkheadforward–Finemeshmodel


33

Section 4: Loadingandboundaryconditions

4.1. TheloadsspecifiedinPARTA,Ch1,4.3,includinginertialloadsduetolongitudinalacceleration,aretobeconsideredinPARTB’sanalysis.

4.2. Whereseparatefinemeshmodelsareusedtoderivethestressresponsesfortheloadcasesasdefinedin4.1andPARTA,Ch1,4.3,themodelsaretobeloadedattheirboundarieswithenforceddisplacementsobtainedfromtheresultsofthePARTAglobalmodel,togetherwithlocalloadswithintheregionofthefinemeshmodel,whereappropriate.Thetranslationalenforceddisplacementsaretobeadjustedasfollows:

a) Forthestillwatercases(seePARTA,Ch1,4.3.1and4.3.2)theenforceddisplacementsaretobecorrectedbytheratiooftherequiredpermissibleSWBMvaluetotheactualbendingmomentappliedtotheglobalmodelatthefinemeshmodellocation.

b) Fortheheadseacases(seePARTA,Ch1,4.3.3and4.3.4)andobliqueseacases(seePARTA,Ch1,4.3.7to4.3.10)theenforceddisplacementsaretobecorrectedbytheratiooftherequiredwavebendingmomenttotheactualbendingmomentappliedtotheglobalmodelatthefinemeshmodellocation.

4.3. Wherethestructuraldetailsarerepresentedbyembeddedfinemeshesintheglobalmodel,thestressresultfortheloadcasesdescribedin4.2(a)and4.2(b)istobecorrectedbytheratiooftherequiredwavebendingmomenttotheactualbendingmomentappliedtotheglobalmodelatthelocationoftheelementunderconsideration.

4.4. Ifthestructuralarrangementissymmetricalabouttheship’scentreline,thenitisonlynecessarytoanalysethestructuraldetailsoneithertheportorthestarboardsideoftheship.Theenforceddisplacementsshouldbetakenfromlocationsonthesideoftheglobalmodelwherethedetailsarerepresentedbythefinemeshmodels.

4.5. Fortheheadseacondition,theloadcombinationsgiveninPARTA,Ch1,Table1.4.2aretobeconsideredforPARTB’sanalysis.

4.6. Fortheobliqueseacondition,theloadcombinationsgiveninPARTA,Ch1,Table1.4.3aretobeconsideredforPARTB’sanalysis.

4.7. AlternativelythestresscombinationsgiveninAppendixDmaybeusedtoobtainthemaximumandminimumlongitudinaldirectstresses,suchasthetangentialstressesinwayofhatchcornerfreeedges,ifthehydrodynamicloadsspecifiedinAppendixCareapplied.However,ifnon‐linearshipmotionanalysisisusedtodeterminethehydrodynamicloads,seePARTA,Ch1,4.2,theloadcombinationsgiveninPARTA,Ch1,Table1.4.3mustbeused.

4.8. Theloadcasecombinationsmaybeobtainedby:

a) Extractingthestressresultsfromselectedfinemeshelementsforeachindividualloadcaseasdefinedin4.1andPARTA,Ch1,4.3.

b) Ifseparatefinemeshmodelsareused,unadjusteddisplacementresultsfromPARTAloadcasesdescribedin4.2(a)and4.2(b)maybeusedandthecorrectionappliedtothestressresult.

c) Useaspreadsheet,orequivalentmethod,tocombinethestressresultsofallspecifiedloadcomponents.


34

d) VonMisesstressesaretobecalculatedbasedonthesumofthedirectstressesandthesumoftheshearstressesfromallloadcomponentsspecified.


5.1. Thedirect(tangential)stressesatthefollowinglocationsaretocomplywiththeacceptancecriteriainTable1.5.1:

atthefreeedgeofthehatchcornerradiiattheupperdeck,

atthefreeedgeofthehatchcoamingtop,

atthefreeedgeofscarphingbracketsbetweenthesuperstructuresideplatingandthetopofthehatchcoaming,

atothercriticallocationswithintheconnection.

5.2. Elsewhere,stresslevelsaretocomplywiththeacceptancecriteriadetailedinTable1.5.2.

5.3. ThefactorsjBOSna,jBOSnb,jBOPnaandjBOPnb,wheren=1to8,specifiedinthecombinationcasesinTable1.5.1aretobeindividuallydeterminedforeachelement.

5.4. Separatehatchcornerradiusplatesformedbyinsertbracketsweldedtothetransverseandlongitudinalstructuresarenotrecommended.Ifsuchbracketsareproposedintheselocations,acceptancewillbesubjecttospecialconsideration.Similarly,proposalstoomitcornerradiiwillbesubjecttospecialconsideration.

5.5. Inrespectofthesuperstructuretocoamingtopscarphingbrackets,itmaybenecessaryfortheweldatthetoeofthebracketatitsconnectionwiththecoamingtopplatetobegroundintoasuitableradiusandbeverifiedfreeofsurfaceimperfections.ThisisinadditiontotherequirementsspecifiedinNote1ofTable1.5.1.


35

Table1.5.1 Acceptancecriteriaforfreeedgesofhatchcornerradiiandscarphingbrackets

Wavedirection StressesforassessmentAllowableStress,N/mm2

(seeNotes1,2and4)

HeadSea

Peakstresses(seePARTA,Ch1,Table1.4.2)

|σ H1a ||σ H2a ||σ H3a ||σ H4a |

1.5 σ (Theoreticalpeakstress,

seeNote3)

Dynamicstressranges(seeNote6)

| σ H1a σ H2b || σ H2a σ H1b || σ H3a σ H4b || σ H4a σ H3b |

600 N/mm (seeNote1)

ObliqueSea

Peakstresses(seePARTA,Ch1,Table1.4.3)

|σ OSna ||σ OSnb ||σ OPna ||σ OPnb |

1, 2 ,3, 4, 5, 6, 7 and 8

1.5 σ (Theoreticalpeakstress,

seeNote3)

Dynamicstressranges(seeNote6)

| σ OS1a σ OS3b || σ OS3a σ OS1b || σ OS2a σ OS4b || σ OS4a σ OS2b || σ OP1a σ OP3b || σ OP3a σ OP1b || σ OP2a σ OP4b || σ OP4a σ OP2b |

| σ OS5a σ OS7b || σ OS7a σ OS5b || σ OS6a σ OS8b || σ OS8a σ OS6b || σ OP5a σ OP7b || σ OP7a σ OP5b || σ OP6a σ OP8b || σ OP8a σ OP6b |

600 N/mm (seeNote1)

where

Forheadseacondition:σ Hna andσ Hnb ,where canbe1, 2, 3or4,arethestressesobtainedfromloadcasesHnaandHnb.SeePARTA,Ch1,Table1.4.2.

istobetakenas1,0ingeneral.Forfreeedgesandplatingclearofwelds,ifthevalueofσ BHna isnegative(i.e.incompression)then maybetakenas0,6.

istobetakenas1,0ingeneral.Forfreeedgesandplatingclearofwelds,ifthevalueofσ BHnb isnegative(i.e.incompression)then maybetakenas0,6.

Forobliqueseacondition:σ OSna ,σ OSnb ,σ OPna andσ OPnb ,where canbe1to8,aredefinedinPARTA,Ch1,Table1.4.3.

istobetakenas1,0ingeneral.Forfreeedgesandplatingclearofwelds,ifthevalueofσ BOSna isnegative(i.e.incompression)then maybetakenas0,6.

istobetakenas1,0ingeneral.Forfreeedgesandplatingclearofwelds,ifthevalueofσ BOSnb isnegative(i.e.incompression)then maybetakenas0,6.

istobetakenas1,0ingeneral.Forfreeedgesandplatingclearofwelds,ifthevalueofσ BOPna isnegative(i.e.incompression)then maybetakenas0,6.

istobetakenas1,0ingeneral.Forfreeedgesandplatingclearofwelds,ifthevalueofσ BOPnb isnegative(i.e.incompression)then maybetakenas0,6.


36

where

j=

jsa=jdl=

jw=

σ =t==n=

=

0,9 forupperdeckhatchwaycornerforwardandaftoftheengineroom0,95 forupperdeckhatchwaycornerforwardandaftofcross‐deckstripswhichhaveawidth(dimensioninthe

longitudinaldirection)greaterthan6w,wherewisthewidthofcrossdeckstripspecifiedinPt4,Ch8,4.4.5oftheRulesforShips

1,0 elsewhere1,0Factorreflectingtherequireddesignfatiguelife= 25/FLY , where,FLYisspecifiedfatiguelifeinyearsbutnottobetakenlessthan25

forfreeedgesandplatinginaccordancewithNote10,7 inwayofweldofscarphingbrackettohatchcoamingtop0,6 inwayofweldendingsYieldstressofmaterialinN/mm2ThicknessofhatchcornerplateThicknesscorrection= 22/ butnottobetakengreaterthan1,00,1forfreeedgesofplating0,25inwayofweldsHightensilesteelcorrectionfactorforfreeedgesandplating:1,0forallsteelgradeshavinganominalyieldstressof235N/mm21,0forallsteelgradeshavinganominalyieldstressof270N/mm21,0forsteelgradesAandDforallnominalyieldstresses1,056forsteelgradesEH32andFH321,12forsteelgradesEH36andFH361,15forsteelgradesEH40andFH401,23forsteelgradesEH471,0forallsteelgradesinwayofwelds

NOTES1. Theallowablestressrangesgiveninthetableapplyto:

TheFREEEDGEofhatchcornerradiusplatingwhichisintegralwiththedeckorhatchcoamingtopplate.Seealso5.1.Thefreeedgeistobefreeofwelding(includingbutts&seams)andgroundsmoothforaminimumdistanceof500mmclearoftheradiustangentpoints.

TheFREEEDGEofscarphingbracketsbetweenthesuperstructuresideplatingandthetopofthehatchcoaming.Thefreeedgeistobefreeofwelding(includingbutts&seams)andgroundsmooth.Theweldconnectiontothehatchcoamingtopistobeofhighqualitydeeppenetrationtype,withsuitabledressingappliedtotheweldendingandsubjecttosuitableNDE.Ideallysuchbracketsshouldbeintegralwiththesuperstructuresideplating.

ForFREEEDGEthatisnotgroundsmoothasindicatedabovebutiscutbymachineflamecuttingwithacontrolledprocedureortheplatethicknessisabove100mm,theallowablestressrangeistobereducedbyafactorof0,89.

2. Seealso5.53. Relevanttotheuseoflinearelasticcodeonly.4. SeealsoFigure1.5.15. IfthestressesarederivedfromtheproceduredescribedinAppendixB,B.4.5.6. WhereaShipRightFDALevel3analysisiscarriedoutandverifiedsufficientfatigueperformanceofastructuraldetail,the

assessmentagainstthedynamicstressrangecriteriaforthestructuraldetailcanbewaived.


37

Table1.5.2 Acceptancecriteriaforprimarystructure

Structuralitems

Wavedirection

(seeNotes1and2)

Allowablestress,N/mm2

Von‐Misesstressσ

Directstressσ

Shearstress τ

Deckplatingoutboardofsidecoaming,seeFig.1.5.1

HeadseaPeakstressAveragestress

σ

0,75σ

ObliqueseaPeakstressAveragestress

σ

0,67σ

Longitudinalhatchcoamingtopplate

HeadseaObliquesea

PeakstressAveragestress

σ

0,75σ

Longitudinalhatchsidecoamingplating

HeadseaObliquesea

PeakstressAveragestress

σ

0,75σ

Superstructuresideplating

HeadseaObliquesea

PeakstressesinscarphingbracketClearofscarphingbracket

σ 0,8σ

where

σ235

N/mm

NOTES

1. SeePARTA,Ch1,Table1.4.2 forheadsealoadcases.2. Forobliqueseaconditions,thefollowingcasesaretobeassessed:

Peakandaveragedirectstresses,seePARTA,Ch1,Table1.4.3orAppendixB,B.4.5ifthestressesarederivedbyconsideringtheequivalentdesignwave(s).

MaximumvonMisesstressesaretobedeterminedbyconsideringtheequivalentdesignwave(s),see4.6andAppendixB,B.4.5.


38

Fig.1.5.1

Acceptancecriteriaforhatchcorners

Part C, Chapter 1 Primary Structure of Container Ship, August 2017

39

PART C:

Verification of Primary Structure

Chapter 1:

Verification of Double Bottom and Transverse

Strength








1.1. PARTCisapplicabletoallcontainershipsforwhichdirectcalculationsarerequired,seealsoINTRODUCTION.

1.2. ForshipswherethecalculationprocedureshavebeenperformedinaccordancewithPARTA,considerationwillbegiventousingasuitablelengthofthatmodel(4baysamidships)withsuitabledetailedfollow‐upmodels.

1.3. Forcontainershipswhichcarryfueloilindeeptanksconstructedintransversebulkheadstructuresorindeeptanksconstructedincontainercargoholds,i.e.fueltankslocatedinboardoftheinnerskinandbetweenadjacenttransversebulkheads,additionalrequirementsarespecifiedinPARTC,Ch4.


2.1. TheobjectiveofPARTC,Ch1istoensurethestructuraladequacyofthefollowingprimarystructurewithregardtolocalloadconsiderations:

doublebottomstructure,

transversestructure,

sidestructure.


40

2.2. TheglobalstrengthofcontainershipsforwhichtheproceduresinPARTAandPARTBhavenotbeencarriedoutistobeincompliancewiththerelevantsectionsoftheRulesforShips(e.g.Pt4,Ch8)andistobeverifiedbytheapplicationoftheappropriateShipRightprograms,contactLloyd’sRegisterlocalofficefordetails.


3.1. Amodeloffour40ftcontainerbays(½hold+1hold+½hold),locatedataboutamidships,istobeconsidered.Iftheshipincorporatesasubstantialfixedguidesystemtoaccommodate20ftcontainers,thenthemodelistoincludethesestructuralitems.

3.2. AtypicalFEmodelarrangementisindicatedinFigs.1.3.1to1.3.4.Thismodelisarrangedsuchthattheopenbulkheadislocatedatthemodelmid‐length.Thealternativearrangementwherebyawatertightbulkheadislocatedatthemodelmid‐lengthwillbeaccepted,buttherequirementsofCh3,3shouldbenoted.

3.3. Themodelistorepresentthefulldepthoftheshipanditisrecommendedthatthefullbreadthbemodelledtosimplifytheanalysisoftheheeledconditions.ItshouldbenotedthatFigs.1.3.1to1.3.4showonlythestarboardhalfofthemodelforclarity.

3.4. Alternatively,ahalf‐breadthmodelmaybeused.Symmetryboundaryconditionsattheship’scentrelinearetobeusedfortheuprightcases.Theheeledconditioncanbeconsideredbycombiningthesymmetricandanti‐symmetriccomponentsintowhichtheheeledconditioncanbeidealised,seeAppendixA.

3.5. TheFEmodelistoberepresentedusingaright‐handedCartesianco‐ordinatesystemwith:

Xmeasuredinthelongitudinaldirection,positiveforward,

Ymeasuredinthetransversedirection,positivetoportfromthecentreline,

Zmeasuredintheverticaldirection,positiveupwardsfromthebaseline.

3.6. Theproposedscantlings,excludingowner'sextrasandanyadditionalthicknessesfittedtocomplywiththeoptionalShipRightESdescriptivenote,aretobeincorporatedinthemodel.Allplatedareas,e.g.shell,innerskin,girders,horizontalstringersandverticalwebsoftransversebulkheads,aretoberepresentedwithplateelementshavingbothmembraneandbendingproperties.

3.7. Secondarystiffeningmembersmaybemodelledusinglineelementspositionedintheplaneoftheplatinghavingaxialandbendingproperties.Thebarelementsaretohave:

across‐sectionalarearepresentingthestiffenerarea;and

bendingpropertiesrepresentingthestiffenerwiththeeccentricityoftheneutralaxis.

3.8. Faceplatestoprimarystiffening(e.g.toverticalwebsoftransversebulkheads)mayberepresentedbylineelementshavingaxialstiffnessonly.Faceplateoftransversebulkheadverticalwebsandhorizontalstringersaretobemodelledasplateelementshavingbendingproperties.However,incorporatingbendingstiffnessinlineelementsmaybetheoptimalmethodofremovingsingularitiesatthefreeedgeofmembraneelements.

3.9. Therecommendedelementsizeisasfollows:

1elementbetweensideandbottomlongitudinalstiffeners,


41

2ormoreelementsbetweentransverseframestoachieveanaspectratiocloseto1.0,

3elementswithinthedepthofprimarystiffening.

3.10. Inprinciple,allopeningsaretoberepresented.Normalsizeaccessopeningsinplatedwebsmaybemodelledbydeletingtheappropriateelements.

Fig.1.3.1

3‐Dfiniteelem

entm

odelforassessmentoftransverseanddoublebottomstrength

(starboardhalfofthemodelisshow

nhereforclarity)


42

Fig.1.3.2

TypicalFEmodelofatransversewebframe

Fig.1.3.3

TypicalFEmodelofanopenbulkhead


43

Fig.1.3.4

TypicalFEmodelofawatertightorclosedbulkhead


4.1. TheloadcasesgiveninTable1.4.1andillustratedinFig.1.4.1aretobeconsidered.

4.2. Theloadcomponentstobeincludedare:

staticanddynamicinertialloadsduetothelightshipmass,see4.5and4.6;

staticanddynamicinertialloadsduetocontainers,see4.5and4.6;

hydrostaticloadsduetoimmersiontothedraughtspecifiedinTable1.4.1.Thehydrostaticloadsaretobeappliedaspressureloadstotheshellenvelope,equivalentintheuprightconditiontoρgh,wherehisthedistanceoftheelementcentroidbelowthestillwaterline;

pressureloadsduetoalocalwavecrestortrough,see4.3;and

hullgirderbendingmomentasspecifiedinTable1.4.1.

4.3. TheadditionalpressureheadtoapplyasaconsequenceofalocalwavecrestortroughisgiveninFig.1.4.2.Thisadditionalpressureistobeappliedoverthefulllengthofthemodel.

4.4. Fortheheeledcases,theloadsaretobecalculatedassumingthattheshipisheldattherequiredstaticheelangle.Thetransverseloadcomponentsofcontainersinholdsaretobedistributedtosuitablelocationsonthetransversebulkheads.Theloadsfromcontainersabovedeckaretobedistributedasshearloadstothetopofthetransversecoaming.The‘overturningmoment’maybeignored.


44

4.5. ForloadcasesC1,C2a,C2b,C3aandC3b,theinertialforceofcontainersandshipmasses,includinggravitationaleffects,aretobecalculatedbasedonthefollowingverticalaccelerationinm/s2.Positiveaccelerationgeneratesanupwardactinginertiaforce.

⋅ ⋅ ⋅ ⋅ ⋅ ⋅ cos ⋅ ψ

where

istheverticalaccelerationduetoheave,inm/s2,giveninPt3,Ch14,1.5.1oftheRulesfor

Ships istheaccelerationduetopitch,inrad/s2,formotioncaseMC1giveninPt3,Ch14,1.5.1of

theRulesforShipsψ isthemaximumpitchangle,indegrees,formotioncaseMC1giveninPt3,Ch14,1.5.1ofthe

RulesforShips isthelongitudinaldistanceofthecontainerunitfromthelongitudinalcentreofmotion,as

definedinPt3,Ch14,1.5.1oftheRulesforShips istheaccelerationduetogravityequalto9,81m/s2

isthehullformcoefficientformotioncaseMC1giveninPt3,Ch14,1.5.1oftheRulesfor

Ships

=‐0,18 =1,00 =‐0,85

=1forloadcaseC3a =‐1forloadcasesC1,C2a,C2bandC3b

4.6. Eachloadcasemaybeanalysedbasedonaconstantverticalaccelerationvalue.Thisaccelerationcanbederivedusingadistance atthelongitudinalcentreofgravityofthecontainerstackwithinthemodellengthwhere:

ThemagnitudeoftheverticalaccelerationismaximumforloadcaseC3a

ThemagnitudeoftheverticalaccelerationisminimumforloadcasesC1,C2a,C2bandC3b

4.7. InertialloadduetoverticalaccelerationneednotbeappliedtoloadcasesC4,C5,C6andC7.However,thegravitationaleffectistobeconsidered.LongitudinalloadscausedbyshiplongitudinalaccelerationistobeappliedforloadcaseC6,seeCh2.

4.8. Iftherequiredhullgirderbendingmomentisnotachievedbytheapplicationoftheship’sloadingconditionandwavepressure,whererequired,theFEstressesaretobeadjustedasfollows:

σ σ _ σ _ ∆BM

σ σ _ σ _ ∆BM

τ τ _ τ _ ∆BM

where

σx,σyandτxy aretheadjusteddirectstressesandshearstressatthecentreoftheelement

σx_FE,σy_FEandτxy_FE aretheFEdirectstressesandshearstressatthecentreoftheelement

σx_u,σy_uandτxy_u arethedirectstressesandshearstressatthecentreoftheelementduetotheunithullgirderbendingmomentloadcase.

ΔBM isthedifferencebetweentherequiredbendingmoment,asspecifiedinTable1.4.1, and resultant bendingmoment from the FEmodel at the longitudinalpositionoftheelement


45

Valuesofσx_u,σy_uandτxy_uaretobederivedbyapplyingaunitbendingmomenttothemodelusingtheboundaryconditionsdescribedinFig.1.5.2.

4.9. Openhatch(hatchcoverless)containerships

4.9.1 For thepurposeof this section, containers above theupperdeck are tobe treated in the samemannerascontainersbelowdeckwithinthehold.

4.9.2 CaseC2bisnotrelevantandistobeomitted.

4.9.3 The cell guide support structure above the upper deck is to be additionally considered, withrespecttoPt3,Ch14oftheRulesforShips.


46

Table1.4.1 Standardloadcasestobeconsidered

Loadcase Description(see4.2)Loadcasetypeandboundary

conditionstoapply

C1

Shiploadingcondition (shipupright)

• Draughtequaltothescantlingdraught,Tsc• Allcontainerbaysandhatchcoversoverthebaysaretobefilledwith40ft

lightcontainers,seeNote1

• Allballastandfueloiltanksinwayofthecargoholdmodelaretobeempty

Wavepressure

• Pressureloadsduetoalocalwavecrest,see4.2

Bendingmoments

•PermissibleSWBM(hogging)

• DesignVWBM(hogging),seeNote3

Symmetric

C2a

Shiploadingcondition (shipupright),seeNote5

• Draughtequaltothescantlingdraught,Tsc

• One40ftcontainerbayandhatchcoversoverthebayaretobeemptyofcontainers

• Theremainingbaysandhatchcoversoverthebaysaretobefilledwith40ftheavycontainerstothemaximumpermittedweight,seeNote2


Wavepressure


Bendingmoments

• PermissibleSWBM(hogging)


Symmetric

C2b

Shiploadingcondition (shipupright),seeNote5

AsforC2aexceptasfollows:

• Allhatchcoversoverthebaysaretobefilledwith40ftheavycontainerstothemaximumpermittedweight,seeNote2

Wavepressure

AsforC2a

Bendingmoments

AsforC2a

Symmetric

C3a


• Shipatlightdraught,seeNote4

• Allcontainerbaysandhatchcoversoverthebaysaretobefilledwith20ftheavycontainerstothemaximumpermittedweight,seeNote2.ForcontainersonhatchcoverwhereRussianStowArrangement(seePt3,Ch14,5.4.9oftheRulesforShips)isadopted,thegreaterofthestackweightsoftheRussianStowArrangementorcombinedweightoftwo20ftcontainerstacksistobeused.


Wavepressure

• Pressureloadsduetoalocalwavetrough,see4.2

Bendingmoments

•PermissibleSWBM(saggingorminimumhogging)

• DesignVWBM(sagging),seeNote3

Symmetric


47

C3b


• Draughtequaltothescantlingdraught,Tsc

•Allcontainerbaysandhatchcoversoverthebaysaretobefilledwith40ftheavycontainerstothemaximumpermittedweight,seeNote2


Wavepressure


Bendingmoments

•PermissibleSWBM(hogging)


Symmetric

C4

Shiploadingcondition(shipheeled)

AsC2aexceptasfollows:

• Meandraughtatcentrelineequaltothescantlingdraught,Tsc

• Staticheelangleequaltothelesserofφandtan‐1(2(D–Tsc)/B),whereφisthemaximumrollangledefinedinPt3,Ch14,1.5.1oftheRulesforShipsbutnottobetakenaslessthan22°.

Wavepressure

• Nowave

Bendingmoments

• AsactualinFEmodel(i.e.noadjustmentrequired)

Asymmetric

C5

Shiploadingcondition(shipheeled)

AsC3aexceptasfollows:

• Meandraughtatcentrelineequaltothescantlingdraught,Tsc

• Staticheelangleequaltothelesserofφandtan‐1(2(D–Tsc)/B),whereφisthemaximumrollangledefinedinPt3,Ch14,1.5.1oftheRulesforShipsbutnottobetakenaslessthan22°.

Wavepressure

• Nowave

Bendingmoments

• AsactualinFEmodel(i.e.noadjustmentrequired)

Asymmetric

C6 Longitudinalloadscausedbyshipaccelerationsactingoncontainers,seeCh2 Symmetric

C7 Damaged(floodedhold)conditions,seeCh3 Asymmetric

NOTES

1. Thecontainerunitweightmaybederivedbasedontheexpectedcargoweightwhenlightcontainersareloadedintheconsideredholdsandhatchcoversabove.Theweightoflightcontainerunitsisnottobemorethanthefollowing: Inhold:55%oftheweightofacorrespondingheavycontainerunitasdefinedinNote2, Ondeckandhatchcovers:90%oftheweightofacorrespondingheavycontainerunitasdefinedinNote2or17metric

tons,whicheveristhelesser.2. Theweightofheavycontainerunitsistobecalculatedasthepermissiblestackingweightdividedbythemaximumnumber

oftiersplanned.3. Thedesignverticalwavebendingmoments(VWBM)aretobeMw(hog)andMw(sag)asspecifiedin2.1ofINTRODUCTION.

Seealso4.8.4. Lightdraughtcorrespondstotheexpecteddraughtamidshipswhenheavycontainersareloadedintheconsideredholds

whilelightercontainersareloadedinotherholds.Thelightdraughtisnottobetakenasgreaterthan0.9Tsc.5. Foronebayemptycondition,ifthecargoholdconsistsoftwoormorebays,theneachbay,andthedeckandhatchcovers

abovewhererequired,aretobeconsideredentirelyemptyinturnasseparateloadcases.Thenumberofloadcasesmaybereducedifthestructuralarrangementissymmetricalaboutmid‐holdandthescantlingenhancementisappliedtoallcargobays.


48

Fig.1.4.1(seecontinuation)

Illustrationofloadingconditions(fordefinitionofwavecrestandtrough,seeFig.1.4.2)


49

Fig.1.4.1(conclusion)

Illustrationofloadingconditions(fordefinitionofwavecrestandtrough,seeFig.1.4.2)


50

Fig.1.4.2

PressureheaddistributionPWforlocalwavecrestandtrough


5.1. TheboundaryconditionstobeappliedtotheFEmodelaredependentontheloadcaseandstructuralcomponenttobeanalysed.Differentboundaryconditionsneedtobeappliedforthesymmetricandasymmetricloadcases.

5.2. TheboundaryconditionsdescribedinthisSectionarepreferred.Alternativeequivalentboundaryconditionsmaybeused.

5.3. Thefollowingboundaryconditionsaretobeappliedtoanalysedifferentstructuralcomponents(seeTable1.5.1):

Set1istobeusedtoanalyseloadcasesC1,C2a,C2b,C3a,C3bandC6.

Set2istobeusedfortheapplicationofhullgirderbendingmoment,see4.8.

Set3istobeusedtoanalysetheheeledconditionloadcasesC4andC5,andthedamaged(floodedhold)loadcaseC7.

5.4. Theboundaryconditionsetstobeusedforfull‐breadthandhalf‐breadthFEmodelsaresummarisedinTable1.5.1andillustratedinFigs.1.5.1to1.5.3.


51

5.5. Fortheheeledloadcases,C4andC5,andthedamaged(floodedhold)loadcase,C7,groundedspringsaretobeappliedtothenodesoftheelementsinthesideshell,innerskin,innerandouterbottom,andtheupperdeckoutsidethelineofhatchesateachendofthemodeltorepresenttheshearstiffnessinducedbytheunmodelledcontainerbays,seeFig.1.5.3.Thespringstiffness,ks,canbecalculatedas:

where

G = modulus of rigidity

l = distance from the bulkhead at the end of the model to the next unmodelled bulkhead

A = average cross‐sectional area of side shell, inner skin, inner bottom, outer bottom or upper deck

outside the line of hatches, as appropriate

N = number of nodes to which the springs are applied.

5.6. Asymmetricboundaryconditionsforhalf‐breadthFEmodels

5.6.1 Forasymmetricloadcasesappliedtohalf‐breadthFEmodels,thesymmetricandanti‐symmetricload components need to be run as separate load cases and then combined to generate the totalasymmetricloadcase.Differentboundaryconditionsarerequiredforthesymmetricandanti‐symmetricloadcomponents.

5.6.2 Thestructural responseofbothsidesof theship forasymmetric loadcaseswillbeobtainedbycombiningtheresultsfromthesymmetricandanti‐symmetricloadcasesasdescribedinAppendixA.

Table1.5.1 Summaryofboundaryconditionstoapply

Load case type Boundary conditions

Half‐breadth FE model

Symmetric load cases Load cases C1, C2a, C2b, C3a, C3b, C6

All load components Set 1 see Fig. 1.5.1

Asymmetric load cases Load cases C4, C5, C7

Symmetric load components

Anti‐symmetric load components

Set 1

Set 3

see Fig. 1.5.1

see Fig. 1.5.3

Symmetric load cases Hull girder bending moment

Bending moment Set 2 see Fig. 1.5.2

Full‐breadth FE model

Symmetric load cases Load cases C1, C2a, C2b, C3a, C3b, C6


Asymmetric load cases Load cases C4, C5, C7


Symmetric load cases Hull girder bending moment

Bending moment Set 2 see Fig. 1.5.2


52

Fig.1.5.1

Set1boundaryconditionsforloadcasesC1,C2a,C2b,C3a,C3bandC6

Boundaryconditionsfortheapplicationofsym

metricloads


53

Fig.1.5.2

Set2boundaryconditionsforapplicationofhullgirderbendingmom

ent


54

Fig.1.5.3

Set3boundaryconditionsforloadcasesC4,C5andC7

Boundaryconditionsfortheapplicationofanti‐sym

metricloadsandboundaryconditionsfortheapplicationofasymmetricloads(full‐breadthmodel)


55


6.1. ThestructureistocomplywiththeacceptancecriteriagiveninTable1.6.1.

6.2. Thebucklingcapabilityofhullstructuresistobeassessedusingaplatethicknessreducedbythecorrosionaddition, tc,inTable1.6.2.

6.3. ThebucklingfactorsofsafetyofhullstructuresaretobederivedaccordingtotheproceduredescribedinShipRightADP(AdditionalDesignandConstructionProcedures)–GuidanceNotesforShipRightSDABucklingAssessment.

6.4. SubjecttoLloyd’sRegister’sagreement,alternativemethodsforbucklingassessmentsmaybespeciallyconsidered.


56

Table1.6.1 Acceptancecriteriaforprimarystructure

StructuralitemLoadcase

Allowablestress,N/mm2(seeNotes2and3) BucklingFactorofsafety

Ω(seeNote1)

VonMisesσe

Longitudinalσx

Transverseσy

(seeNote4)

Shearstressτ

(seeNote5)

Bottomshell

C1C2aC3aC3b

— 0,92σL 0,63σ0 — 1,1

Doublebottomgirders

C1C2aC2bC3aC3b

σL 0,92σL — 0,46σL 1,1

Innerbottom

C1C2aC3aC3b

σL 0,92σL 0,63σ0 — 1,1

Doublebottomfloors

C1C2aC4C5

0,75σ0 — 0,63σ0 0,35σ0 1,2

SideshellLongitudinalbulkhead

C1C2aC3aC3bC4C5

σL 0,92σL 0,63σ0 0,46σL 1,1

Sidestringers

C1C2aC4C5

σL 0,92σL — 0,46σL 1.1

Sidetransverses

C1C2aC4C5

0,75σ0 — 0,63σ0 0,35σ0 1,2

Transversebulkheadsallstructures

C6C7

seeCh2seeCh3

Transversebulkheadplating

C1C2aC2bC4C5

0,75σ0 — 0,63σ0 0,35σ0

1,1

Transversebulkheads:•verticalwebplating•verticalfacebars•horizontalwebplating•horizontalfacebars

C1C2aC2bC4C5

0,75σ0 — 0,63σ0 — 1,1

Cross‐deckboxtransverses

C4C5

0,75σ0 — 0,63σ0 0,35σ0 1,2


57

Table1.6.1 (Continuation):Acceptancecriteriaforprimarystructure

where σL=235/kL

NOTES

1. Thepanelthicknessistobereducedbytheamounttc indicatedinTable1.6.2.Thelocalstressesaretobeincreasedin the ratio of t/(t – tc), where t is the thickness used in the FEmodel. These local stressesmay be obtained bydeducingthestressesduetoglobalbendingmomentgeneratedintheFEmodelfromtheFEstresses.

2. Forshellelements,thespecifiedallowablestressesaretobecomparedwiththemembranestressintherelevantstructuralitem.

3. Inareaswheretheopeningshavenotbeenmodelled,theresultingshearstressandvonMisesstressaretobecorrectedaccordingtotheratiooftheactualtothemodelledsheararea.Iftheresultingstresslevelexceeds90%ofthespecifiedallowablevalue,furtherstudybymeansoffinemeshfollow‐upmodelsmayberequired.

4. Forbottomshell,innerbottomandtransversebulkheadplating,σyisthestressintheplaneoftheplatinginthetransversedirection.Forsideshellandlongitudinalbulkhead,σyisthestressintheplaneoftheplatingparalleltothespanofthesidetransverse.Forallothermembers,σyisthedirectstressinthedirectionofthemember’sspan.

5. Thespecifiedvaluesrelatetothemeanshearstressoverthedepthofthemember.Thepeakstressisnottoexceed1.1×allowablevalue.

Table1.6.2 Standardthicknessdeductionstobeusedtoderivecriticalbucklingstresses

Structuralitem Thicknessdeduction,tcinmm

Deckplating 1,0

Shellplating 1,0

Innerbottomplating 1,0

Longitudinalbulkhead(innerskin) 1,0

Crownofsidetanks(e.g.2ndDeck) 1,0

Internalstructureofdoublebottomandsidetanks 1,0

Transversebulkheads,watertightandopen 0,0

Cross‐deckstructure(e.g.topboxsidesandbottom) 0,0


58

PART C:


Chapter 2:

Transverse Bulkhead and Mid‐Hold Support

Structures: Surge (Fore and Aft) Loading







1.1. TheobjectiveofPARTC,Ch2istoensuretheadequacyoftransversewatertightbulkheadsandmid‐holdsupportstructures(openbulkheads)undertheeffectoflongitudinalloadsarisingfromlongitudinalaccelerationsactingonthecontainers.Theacceptancecriteriaaregivenin5.2.

1.2. ThisassessmentandtheinclusionofthisloadcomponentintheproceduresofPARTAandPARTBarenotrequiredforcontainershipsthathavecontinuouslongitudinaldeckgirdersarrangedsuchthatthespanofthecross‐deckboxesdoesnotexceed13.0m.Thespanofthecross‐deckboxistobecalculatedtakingintoaccountthepresenceofthecontinuouslongitudinaldeckgirders,butignoringendbrackets,etc.Longitudinaldeckgirdersorbulkheadsarenottobeconsideredcontinuousiftheircontinuouslongitudinalextentislessthanalengthequivalenttofour(4)40ftcontainerbays.

1.3. IftheproceduresinPARTAandPARTBarenotrequired,thentheanalysisindicatedinthischapteristobecarriedout,withtheexceptionofshipsthathaveastructuralarrangementwhichsatisfiesthedescriptionin1.2.

1.4. WherethisanalysisiscarriedoutinPARTAusingafullshipFEmodel,theanalysisinthischaptercanbewaived.


2.1. ThemodeldescribedinPARTC,Ch1maybeused.IfPARTA’sanalysisiscarriedoutusingafullshipmodelthentheloadscanbeapplieddirectlytothefullshipmodel.


59


3.1. Thisloadingassessestheeffectsoflongitudinalloadscausedbyshipaccelerationsactingoncontainers,onthetransversebulkheadandcross‐deckstructures.Thelongitudinalacceleration,ax,attherequiredlocationsistobecalculatedusingthelongitudinalaccelerationformulaegiveninPt3,Ch14,8.2.5oftheRulesforShips.Thefollowingmotioncases,definedinPt3,Ch14,Table14.8.4oftheRulesforShips,aretobeapplied:

Headsea: MC1(HS_1) Positivepitchaccelerationcase

MC1 (HS_2) Negative pitch acceleration case

Obliquesea: MC3(OS1_1) Positivepitchaccelerationcase

MC3 (OS1_2) Negative pitch acceleration case

NotethatlongitudinalaccelerationduetoMC1(HS_2)isequalinmagnitudetoMC1(HS_1)buttheyareinoppositedirections.Likewise,longitudinalaccelerationsduetoMC3(OS1_1)andMC3(OS1_2)areequalinmagnitudebutoppositeindirection.

3.2. IfthelongitudinalloadsarenotrequiredtobeconsideredintheanalysisinPARTAandPARTB,see1.3,thentheloadingconditionC6(seeCh1,Table1.4.1)maybebasedonthelargestaccelerationoftheheadseaandobliqueseaconditions.

3.3. Nootherloadsaretobeapplied.


60

Table2.3.1 Assumptionsregardinglongitudinalloadsandtheirapplication

Locationofcontainers Assumptions

Containersinholdforallcontainerships

Thelongitudinalforceistobecalculatedatthecentreofeachcontainerandistobesuitablydistributedtothebulkheadprimarymembersinwayofthecellguides.

Containersonhatchcovers

Thelongitudinalforceistobecalculatedatthemid‐heightofthestack.

Thefollowingassumptionsaretobemade:

• windloadsmaybeneglected

• self‐weightofthehatchcoveristobetakenintoaccount

• thestackistocontainthemaximumnumberofloadedtiers,asspecifiedintheLoadingManual(LM)orCargoSecuringManual(CSM)

• theweightofcontainersistobetakenasthemaximumpermittedbytheLoadingManual

• allloadsarisingfromcontainersonthehatchcoversaretobeappliedasforcestothehatchcoamingtop

• themomentaboutthestackbasecausedbythelongitudinalforcemaybeignored

• longitudinalforcesfromcontainerssitedbetweentheship'ssideandthelongitudinalcoaming(i.e.notsitedonthehatchcovers)maybeignored

• 15%ofthetotalforceactingonthehatchcoveristobedistributedasalineloadtothetopofthehatchcoamings(transverseandlongitudinal)onwhichthecoverrests.Thisrepresentstheloadwhichcouldbeassumedtobetakenbyfrictionatbearingpadsand/orsealingarrangements

• theremaininglongitudinalforcesactingonthehatchcoveraretobetakenasactingatthehatchcoverlongitudinalstopperpositions.Ifthestopperpositionsareunknown,thentheyaretobelocatedatthemid‐breadthoftheaftendofthecovers.3coversaretobeassumedifthenumberofcoversisnotknown.

Containersabovedeckforhatchcoverlessships

Thelongitudinalforceistobecalculatedatthecentreofeachcontainerandistobesuitablydistributedtothecellguidesupportstructureandbulkheadprimarymembersasappropriate.

NOTES

1. Positivelongitudinalacceleration(forwardparalleltodeck)generateslongitudinalforceactingbackward.Negativelongitudinalaccelerationcreateslongitudinalactingforward.

2. ThecentreofgravitypositionanddistributionoflongitudinalforceofacontainerduetoshipmotionistobeinaccordancewithPt3,Ch14,9.2oftheRulesforShips.


4.1. BoundaryconditionSet1,seeCh1,Fig.1.5.1istobeused.


5.1. WherethestructuralitemsareassessedusingPARTA’sprocedurewithafullshipFEmodel,see1.4,theacceptancecriteriasetoutinPARTAaretobecompliedwith.

5.2. WherePARTA’sprocedureisnotcarriedout,thevonMisesstressesinthebulkheadstructuresandthecross‐deckstructuresundertheloadingscenariosdefinedinthisSectionarenottoexceed0,25σo.Singleelementvaluesinwayoftheapplicationofloadsarisingfromthecontainersonhatchcoversmayexceedthisvalue,butarenottoexceed0,4σo.Aminimumbucklingfactorofsafety,Ω,of1,3istobeachieved.


61

PART C:


Chapter 3:

Transverse Watertight Bulkhead Assessment in

Damaged (Flooded Hold) Condition






1.1. ThepurposeofthisChapteristoensurethatthestructuralintegrityofthetransversewatertightbulkheadsisnotcompromisedifthecontainerholdisfloodedasaresultofcollisionorotheraccidentaloccurrence.

1.2. Thewatertightbulkheadsaretobecapableofresistingtheimposedloadscausedbyfloodwater,includingtheeffectofshipmotionsandaccelerationsinadditiontothenormaloperatingloads.

1.3. WatertightbulkheadstructureswhichcomplywiththesimplifiedloadingandacceptancecriteriasetoutinthisChapterareconsideredtosatisfytherequirementsof1.2.Proposalsforalternativeassessmentproceduresaretoincludeevidencethattherequirementsof1.2andtheacceptancecriteriainSection4aretobesatisfied.


2.1. ThemodeldescribedinCh1istobeused.Iftheverificationofbucklingfactorofsafetyofthefaceplateofthetransversewatertightbulkheadverticalwebsandthehorizontalstringersistobewaived,thefaceplatethicknessintheFEmodelistoberepresentedbyareducedthicknessequalto40percentoftheoriginalthickness.

2.2. BoundaryconditionSet3,asgiveninCh1,Fig.1.5.3,istobeused.


3.1. Sufficientloadcasesaretobeconsideredtoenableassessmentoftheresponseoftypicaltransversewatertightbulkheadstofloodingandotherloads.

3.2. Formodelswhichhavebeenarrangedwithawatertighttransversebulkheadatthemid‐lengthoftheFEmodel,itwillbenecessarytoconsidertwoseparatefloodingscenarios:


62

a) theafterholdisflooded,

b) theforwardholdisflooded.

3.3. Formodelswhichhavebeenarrangedwithanopenbulkheadatthemid‐lengthoftheFEmodel,seeFig.1.3.1inCh1,onlythescenariowiththeholdatthemid‐lengthfloodedneedstobeconsidered.Theresponseofbothwatertightbulkheadsofthisholdistobecomparedwiththeacceptancecriteria.

3.4. Forthefloodingscenariosspecifiedin3.2and3.3,twobasicloadingconditionsaretobeanalysed:

a) ConditionC7a,whichassumesthatnocontainersarecarriedonhatchcovers,

b) ConditionC7b,whichassumesthatthehatchcoversarefullyloadedwithcontainerstothemaximumpermittedweightbytheship’sLoadingManual.

Theshipisassumedtobeinaheelcondition.TheloadstobeappliedareasspecifiedinTable3.3.1andshowninFigs.3.3.1and3.3.2.

3.5. ConditionC7bistobeomittedforhatchcoverlesscontainerships.


63

Table3.3.1 Summaryofloadingconditionswithoneholdflooded(alsoseeFig.3.3.2)

ItemLoadingcondition,C7

ConditionC7a ConditionC7b

Transversewatertightbulkheadsoffloodedhold

Pressurebasedonthesumof1)thepressureheadduetodamagedheelwaterlineand2)pitchmotion.

1) Thedamagedheelwaterlinemaybedeterminedbasedonthedamagestabilityinformation.Thefollowing2separateconditionsaretobeconsidered:- Maximumdraughtatcentrelineoftheforwardandaftbulkheads

ofthefloodedhold( - Maximumdraughtatinnerhulllongitudinalbulkheadofthe

forwardandaftbulkheadsofthefloodedhold(

Theabovefloodingconditionsmayberepresentedusingasingleloadcaseifthemaximumloadsresultingfromtheseconditionsareapplied.

2) Pressureheadduetoship’spitchmotion:

Thepressurehead isgivenby:

0,35 tan ψ

isthelengthofthefloodedhold

ψisthepitchanglecalculatedinaccordancewithPt3,Ch14,Table14.8.1oftheRulesforShips

Wherenodamagestabilityinformationisavailable, and canbeobtainedasfollows:

1,2 1,025

(inm)

tobetakenatfreeboarddeckatside(normally2nddeck)

where

isthevolumeofthefloodedcompartmentcorrespondingtothelevelofscantlingdraught(inm3)

TPCisthedisplacement(tonnes)immersionpercentimetreasgivenintheship’sLoadingManual

needsnottobetakengreaterthan .

Sideandbottomshell Pressurebasedonheeledwaterlinedefinedby and

Watertightlongitudinalbulkheads,decksandinnerbottomoffloodedhold Pressurebasedonheeledwaterlinedefinedby and

Containersinfloodedhold Emptyofcontainers

Containersinnon‐floodedhold Fullyloadedwithmaximumpermitted40ftcontainers

Ballasttanksinwayoffloodedhold Floodedtothelevelofwaterlinedefinedby and

Containersonhatchcovers NocontainersFullyloadedwithmaximumpermitted40ftcontainers

NOTE

Thepressureheadtobeappliedtotheexternalshellplatingandlongitudinalinternalplatingisdifferenttothatspecifiedforthebulkhead.Thepurposeoftheseloadcasesistoimposefloodwaterloads,includingtheeffectofshipmotionsandaccelerations,ontothebulkheadstructure;hencetheincreasedpressureheadappliedtothebulkhead.


64

Fig.3.3.1

Loadingconditionsforfloodedloadcases


65

Fig.3.3.2

Headsofwaterforfloodedloadingconditions


4.1. ThetransversewatertightbulkheadsandtheirsupportingstructuresmustsatisfytheacceptancecriteriagiveninTable3.4.1whensubjectedtotheloadsspecifiedinSection3.


66

Table3.4.1 Acceptancecriteriaforloadingconditionswithoneholdflooded

Structuralmemberoftransversewatertightbulkhead

Allowablestress,N/mm2Bucklingfactor

ofsafety

Ω(seeNote1)VonMises

σe

Directstress

σ

Shearstressτ

(seeNote2)

Bulkheadplating σ0 0,95σ0 0,55σ0 1,1

Verticalwebsandhorizontalstringers:

(a)Webplating

(b)Faceplates

σ0 0,95σ0 0,55σ0 1,0

— σ0 —1,0

(seeNote3)

Cross‐deckboxstructure σ0 0,95σ0 0,55σ0 1,0

Doublebottomgirdersandsidestringersinwayofendconnectionsofbulkheadprimarymembers

σ0 0,95σ0 0,55σ0 1,0

NOTES

1.Thebucklingcapabilityofthestructuresistobeassessedusingaplatethicknessreducedbythecorrosionaddition,tc,inCh1,Table1.6.2.

2. Allowablestressrelatedtoelementshearstresses.

3. VerificationofbucklingfactorofsafetyoffaceplatemaybewaivedifthethicknessintheFEmodelisrepresentedbyareducedthicknessequalto40percentoftheoriginalthickness.


67

PART C:


Chapter 4:

Transverse Bulkhead Structures: Additional

Requirements for Fuel Oil Deep Tanks








1.1. ThisChapterisapplicabletocontainershipswhichcarryFuelOil(FO)indeeptanks,constructedintransversebulkheadstructures,orincontainercargohold,i.e.fueltankslocatedinboardoftheinnerskin,abovetheinnerbottom,andbetweenadjacenttransversebulkheads.

1.2. ForshipswherethecalculationprocedureshavebeenperformedinaccordancewithPARTA,considerationwillbegiventousingasuitablelengthofthatmodelwithsuitabledetailedfollowupmodels.

1.3. TheanalysisspecifiedinthisChapterisadditionaltothatspecifiedinCh1.

1.4. Forcontainershipsintendedtooperateinareassubjecttolowairtemperatures,theremaybearequirementtoassesstheeffectoftheheatedcargooncritical.WhereFOiscarriedintransversedoubleplatedbulkheadsinwhichalltheprimarystructuresareconnectedtobothofthebulkheadplatings,thestructuralanalysisdescribedinSections2to6ofthisChaptermaybeomitted.

1.5. SeealsoCh5.


2.1. TheobjectiveofSections3to6istoverifythestructuralarrangementsoftheprimarystructureofthefueloildeeptanks.

2.2. ThelocalstrengthofthecontainerholdstructureistobeverifiedbyChapters1,2and3asapplicable.


68

2.3. TheglobalstrengthofacontainershipforwhichPARTSAandBhavenotbeenappliedmustcomplywiththerelevantSectionsoftheRulesforShips,(Pt4,Ch8)andthisistobeverifiedbytheapplicationoftheappropriateShipRightprogram.

2.4. TheobjectiveofCh5istoprovideloadcomponentsforPARTB’sanalysis.IfPARTB’sanalysisisnotrequiredthentheanalysisdescribedinCh5isalsonotrequired.


3.1. Amodelistobeconstructedextendingfromone40ftbayaftoftheaftmostfueloildeeptankbulkheadtoone40ftbayforwardoftheforemostfueloildeeptankbulkhead.

3.2. ThismodelistobedevelopedinaccordancewithCh1,3.3to3.10.

3.3. Thefaceplatesandplatestiffenersofprimarymembersaretoberepresentedbylineelementswiththecross‐sectionalareamodified,whereappropriate,inaccordancewithTable4.3.1andFig.4.3.1.

Table4.3.1 Lineelementeffectivecross‐sectionalarea

Structurerepresentedbyelement Effectivearea,Ae

Primarymemberfacebars Symmetrical Asymmetrical

Ae = 100%AnAe = 100%An

Curvedbracketfacebars(continuous) Symmetrical Asymmetrical

seeFig.4.3.1

Straightbracketfacebars(discontinuous)

Symmetrical Asymmetrical

Ae = 100%AnAe = 60%An

Straightbracketfacebars(continuousaroundtoecurvature)

Straightportion Symmetrical Asymmetrical

Ae = 100%AnAe = 60%An

Curvedportion Symmetrical Asymmetrical

seeFig.4.3.1

Webstiffeners–snipedbothends

Flatbars Ae = 25%stiffenerarea

Othersections

Ae =p

o

A

r

YI

A–

2

Webstiffeners–snipedoneend,connectedotherend

Flatbars Ae = 75%stiffenerarea

Othersections

Ae =p

o

A

r

YI

A–

2

2

Symbols

A = cross‐sectionareaofstiffenerandassociatedplatingAn = averagefacebarareaoverlengthoflineelementAp = cross‐sectionareaofassociatedplatingI = momentofinertiaofstiffenerandassociatedplatingY0 = distanceofneutralaxisofstiffenerandassociatedplatingfrommedianplaneofplate

r = radiusofgyration=A

I


69

Fig.4.3.1

Effectiveareaofcurvedfacebars


70


4.1. TheloadcasesrequiredareillustratedinFigs.4.4.1(a)to4.4.1(d)forarrangementofthree,four,fiveandsixabreastfueloiltanks.Iftheship’sLoadingManualconsistsofloadingconditionswithtwoormoreadjacentfueloiltanksfilledandotherfueloiltanksempty,theseconditionsarealsotobeinvestigatedinadditiontothoseshowninthefigure.Theloadcomponentstobeincludedare:

staticanddynamicinertialloadsduetothelightshipmass,see4.7and4.8;

staticanddynamicinertialloadsduetocontainersandfluidintanks,see4.7and4.8;

thehydrostaticloadsduetoimmersiontothedraughtspecified.Thehydrostaticloadsaretobeappliedaspressureloadstotheshellenvelope,equivalentintheuprightconditiontoρgh,wherehisthedistanceoftheelementcentroidbelowthestillwaterline;

pressureloadsduetoalocalwavecrestortrough,see4.4;

overpressureoftanks,see4.2;

hullgirderbendingmomentsasspecifiedinTable4.4.1;and

hullgirdershearforcesasspecifiedinTable4.4.1.

4.2. Theoverpressureheadiscalculatedasfollows:

ForloadcasesD1toD6 Max(hof,h/2)inmetres

ForloadcasesD7andD8 Max(2,4,h)inmetres

where

histheverticaldistancebetweenthecrownoftheFOtankandthetopoftheoverflow;and

hofistheheightoftheoverflowmeasuredfromthedeckonwhichitisfitted,seeFigs4.4.1(a)to4.4.1(d)

4.3. Fordesignpurposes,fueloilistobeassumedtohaveaspecificgravityof1,0.

4.4. Forcasesrequiringtheconsiderationofwavecrestandtroughconditions,thewavepressuredistributiontobeappliedisdescribedinCh1,Fig1.4.2,withthedraught,Tsc,takenasthescantlingdraughtorlightestloadeddraught,asappropriate.Theexternalpressuremaybetakenasuniformoverthemodellength.

4.5. Fortheheeledcases,D5andD6,thestaticheelangleistobetakenasthelesserofφandtan‐1(2(D–Tsc)/B),whereφisthemaximumrollangledefinedinPt3,Ch14,1.5.1oftheRulesforShipsbutnottobetakenaslessthan22○.Themeandraughtatcentrelineistobetakenasthescantlingdraught.

4.6. ForloadcasesD1toD8,theeffectofhullglobalbendingmomentandshearforcearetobeincludedasspecifiedinTable4.4.1.

4.7. ForloadcasesD1,D2,D3andD4,theinertialforceofcontainers,shipmassesandfluidintanksduetoverticalacceleration,includinggravitationaleffect,aretobecalculatedinaccordancewithCh1,4.5,withthefollowing factorapplied:

=1forloadcaseD4 =‐1forloadcasesD1,D2andD3


71

4.8. InertialloadduetoverticalaccelerationneednotbeappliedtoloadcasesD5,D6,D7andD8.However,thegravitationaleffectistobeconsidered.

4.9. WheretherequiredhullgirderbendingmomentspecifiedinTable4.4.1isnotachievedbytheapplicationoftheship’sloadingconditionandwavepressure,theFEstressesaretobeadjustedasfollows:

σ σ _ σ _ ∆BM

σ σ _ σ _ ∆BM

τ τ _ τ _ ∆BM

where

σx,σyandτxy aretheadjusteddirectstressesandshearstressatthecentreofanelement

σx_FE,σy_FEandτxy_FE arethefiniteelementdirectstressesandshearstressatthecentreoftheelement

σx_u,σy_uandτxy_u arethedirectstressesandshearstressatthecentreoftheelementduetotheunithullgirderbendingmomentloadcase

ΔBM isthedifferencebetweentherequiredbendingmoment,asspecifiedinTable4.4.1,andtheresultantbendingmomentfromtheFEmodelatthelongitudinalpositionoftheelement.

Valuesofσx_u,σy_uandτxy_uaretobederivedbyapplyingaunitbendingmomenttothemodelusingboundaryconditionsofloadcaseD9asdescribedinFigure4.4.2.

4.10. LoadcaseD10(seeFigure4.4.3)representstheloadingandboundaryconditionstobeadoptedfordeterminingthestresscomponentsduetoglobalshearforceforloadcasesD1toD4,seeTable4.4.1.ThedifferencebetweentherequiredshearforceinTable4.4.1andtheshearforceduetotheapplicationoftheship’sloadingconditionandwavepressureistobeappliedatthemodelend.

4.11. LoadingconditionsforcommonconfigurationsoffueloildeeptanksareillustratedinFigs.4.4.1(a)to(d).Loadingconditionsforotherconfigurationswillbeconsidered,suchthatsimilarloadingscenariosonthecontainmentstructureareachieved.


72

Table4.4.1 Applicationofglobalbendingmomentsandshearforcestoloadcases

LoadcaseCondition(seeNote3)

Wavepressure

Globalbendingmoment Globalshearforce

D1,D2andD3

Shipupright

•Scantlingdraught,Tsc•Containerbaysinholdsand

hatchcoversoverthebaysaretobefilledwith20ftheavycontainerstothemaximumpermittedweight,seeNote4.Containerbaysabovefueloiltanksaretobeempty.

Wavecrest

•PermissibleSWBM(seagoinghogging)

•DesignVWBM(hogging),seeNote1

—

•AsactualinFEmodel(i.e.noadjustmentrequired)

Atfwdoil‐tightbulkhead

•PermissibleSWSF(‐ve)•DesignVWSF(‐ve)


Ataftoil‐tightbulkhead

•PermissibleSWSF(+ve)•DesignVWSF(+ve)

D4

Shipupright

•Lightdraught,seeNote6•Allcontainersabovefueloil

tanksandonhatchcoversaretobeloadedwith20ftheavycontainerstothemaximumpermittedweight,seeNotes4and5.Containersinholdsaretobeempty.

Wavetrough

•PermissibleSWBM(seagoingsaggingorminimumhogging)

•DesignVWBM(sagging),seeNote1

—


Atfwdoil‐tightbulkhead

•PermissibleSWSF(+ve)•DesignVWSF(+ve)


Ataftoil‐tightbulkhead

•PermissibleSWSF(‐ve)•DesignVWSF(‐ve)

D5andD6Shipheeled

•Scantlingdraught,Tsc•Nocontainers

— •AsactualinFEmodel(i.e.noadjustmentrequired)

—

D7andD8Shipupright(Testcondition)

•Draughtat0,25D•Nocontainers

— •PermissibleSWBM(harbourhogging)

—

NOTES

1. Thedesignverticalwavebendingmoments(VWBM)aretobeMw(hog)andMw(sag)asspecifiedin2.1ofINTRODUCTION.Seealso4.9.

2. Thedesignverticalwaveshearforces(VWSF)aretobeQw+andQw‐asspecifiedin2.1ofINTRODUCTION.3. AllballasttanksinwayofthecargoholdmodelforloadcasesD1,D2,D3,D5,D6,D7andD8aretobeempty.Fueloiltanks

aretobeloadedinaccordancewiththatindicatedinFig.4.4.1(a)to(d).4. Theweightofheavycontainerunitsistobecalculatedasthepermissiblestackingweightdividedbythemaximum

numberoftiersplanned.

5. ForcontainersonhatchcoverswheretheRussianStowArrangement(seePt3,Ch14,5.4.9oftheRulesforShips)isadopted,thegreaterofthestackweightsoftheRussianStowArrangement,orthecombinedweightoftwo20ftcontainerstacksistobeused.

6. Lightdraughtcorrespondstotheexpecteddraughtamidships,whenheavycontainersareloadedintheconsideredholds,whilelightercontainersareloadedinotherholds.Thelightdraughtisnottobetakenasgreaterthan0.9Tsc.


73

Typicalarrangement

LoadcaseD1—scantlingdraught+wavecrest


Fig.4.4.1(a)(seecontinuation)

Loadingconditions—Fueloildeeptankswithtwolongitudinalbulkheads


74


LoadcaseD4—lightestloadeddraught+wavetrough

LoadcaseD5—scantlingdraught+staticheel(see4.5)


75


LoadcaseD7—tanktestcondition(draught=0.25D)


Fig.4.4.1(a)(conclusion)

Loadingconditions—Fueloildeeptankswithtwolongitudinalbulkheads


76

Typicalarrangement

LoadcaseD1—scantlingdraught+wavecrest(seeNotes)


Fig.4.4.1(b)(seecontinuation)

Loadingconditions—Fueloildeeptankswiththreelongitudinalbulkheads


77





78




Fig.4.4.1(b)(conclusion)

Loadingconditions—Fueloildeeptankswiththreelongitudinalbulkheads

NOTES

1. Iftheship’sLoadingManualincludesloadingconditionswithtwoormoreadjacentfueloiltanksfilled,andotherfueloiltanksempty,theseconditionsarealsotobeinvestigated.

2. Theactualloadingconditionsdependonthestructuralarrangementandmaybedifferenttothatshowninthefigure.ItisrecommendedthatthedesignerdiscussestheanalysisrequirementswithLloyd’sRegisterearlyoninthedesigncycle.


79

Typicalarrangements



Fig.4.4.1(c)(seecontinuation)

Loadingconditions—Fueloildeeptankswithfourlongitudinalbulkheads


80





81




Fig.4.4.1(c)(conclusion)

Loadingconditions—Fueloildeeptankswithfourlongitudinalbulkheads

NOTES1. Iftheship’sLoadingManualincludesloadingconditionswithtwoormoreadjacentfueloiltanksfilled,andotherfueloiltanksempty,theseconditionsarealsotobeinvestigated.



82

Typicalarrangements



Fig.4.4.1(d)(seecontinuation)

Loadingconditions—Fueloildeeptankswithfivelongitudinalbulkheads


83





84




Fig.4.4.1(d)(conclusion)

Loadingconditions—Fueloildeeptankswithfivelongitudinalbulkheads

NOTES1. Iftheship’sLoadingManualincludesloadingconditionswithtwoormoreadjacentfueloiltanksfilled,andotherfueloiltanksempty,theseconditionsarealsotobeinvestigated.



85

Fig.4.4.2

LoadcaseD9:M

omentcase

ResultsofthiscasearetobeaddedtoresultsofloadcasesD1,D2,D3,D4,D7andD8

SeeTable4.4.1and4.6


86

Fig.4.4.3

LoadcaseD10:Shearcase

ForcombinationwithresultsofloadcasesD1toD4asspecifiedinTable4.4.1


87


5.1. TheboundaryconditionstobeappliedtoloadcasesD1toD8aredefinedinCh1,5.

5.2. BoundaryconditionsforloadcasesD9andD10aregiveninFigs.4.4.2and4.4.3respectively.TheseboundaryconditionstobeappliedaresummarisedinTable4.5.1.

Table4.5.1 Summaryofboundaryconditionstoapply

Loadcasetype Boundaryconditions

Half‐breadthFEmodel

Symmetricloadcases LoadcasesD1,D2,D3,D4,D7andD8

Allloadcomponents Set1 seeFig.1.5.1ofCh1,5

Asymmetricloadcases LoadcasesD5andD6

SymmetricloadcomponentsAnti‐symmetricloadcomponents

Set1Set3

seeFig.1.5.1ofCh1,5seeFig.1.5.3ofCh1,5

Symmetricloadcases Hullgirderloads

Bendingmoment D9 seeFig.4.4.2

Shearforce D10 seeFig.4.4.3

Symmetricloadcases Hullgirderbendingmoment

Bendingmoment Set2 seeFig.1.5.2ofCh1,5

Full‐breadthFEmodel

Symmetricloadcases LoadcasesD1,D2,D3,D4,D7andD8


Asymmetricloadcases LoadcasesD5andD6


Symmetricloadcases Hullgirderloads

Bendingmoment D9 seeFig.4.4.2

Shearforce D10 seeFig.4.4.3


6.1. ThestructureofthefueloildeeptankistocomplywiththeacceptancecriteriagiveninTable4.6.1.

6.2. Thebucklingcapabilityofthestructuresistobeassessedusingaplatethicknessreducedbythecorrosionaddition,tc,seeCh1,Table1.6.2.

6.3. ThebucklingfactorsofsafetyofhullstructuresaretobederivedaccordingtotheproceduredescribedinShipRightADP(AdditionalDesignandConstructionProcedures)–GuidanceNotesforShipRightSDABucklingAssessment.


88

Table4.6.1 Acceptancecriteriaforprimarystructureof,andinwayof,thefueloildeeptanks

Structuralitem Loadcase

Allowablestress,N/mm2(seeNotes2and3)

BucklingfactorofsafetyΩ

(seeNote1)VonMisesσe

Longitudinalσx

Transverseσy

(seeNote4)

Shearstressτ

(seeNote6)

BottomshellInnerbottomDoublebottomgirders

D1toD8 σL 0,92σL 0,63σo 0,46σL 1,1

Oil‐tightlongitudinalbulkhead

D1toD4,D7andD8

0,75σo — 0,63σo0,35σo

(seeNote7)1,2

D5andD6 — — 0,63σo 0,35σo 1,2

SideshellSidestringersInnerhulllongitudinalbulkhead

D1toD4,D7andD8

σL 0,92σL —0,46σL

(seeNote7)1,1

D5andD6 σL 0,92σL — 0,46σL 1,2

TransversestructureDoublebottomfloors

D1toD8 0,75σo — 0,63σo 0,35σo 1,2

Transversebulkheadstructures

D1toD4,D7andD8 0,75σo — 0,63σo 0,35σo 1,1

D5andD6 0,75σo — 0,63σo 0,35σo 1,2

Cross‐deckboxstructure

D1toD8 0,75σo — 0,63σo 0,35σo 1,2

Transversestructurefaceplate

D1toD8 — 0,75σo — — —

NOTES

1. ThepanelthicknessistobereducedbytheamounttcasindicatedinCh1,Table1.6.2.Thelocalstressesaretobeincreasedbytheratiooft/(t–tc),wheretisthethicknessusedintheFEmodel.TheselocalstressesmaybeobtainedbydeducingthestressesduetoglobalbendingmomentgeneratedintheFEmodelfromtheFEstresses.

2. Forshellelements,thespecifiedallowablestressesaretobecomparedwiththemembranestressesintherelevantstructuralitem.

3. Inareaswheretheopeningshavenotbeenmodelled,theresultingshearstressandvonMisesstressaretobecorrectedaccordingtotheratiooftheactualtothemodelledsheararea.Iftheresultingstresslevelexceeds90%ofthespecifiedallowablevalue,furtherstudybymeansoffinemeshfollow‐upmodelsmayberequired.

4. Forbottomshellandinnerbottomplating,σyisthestressintheplaneoftheplatinginthetransversedirection.Forsideshellandlongitudinalbulkhead,σyisthestressintheplaneoftheplatingparalleltothespanofthesidetransverse.Forthetransversebulkheadplating,σyisthestressintheplaneoftheplatinginthetransverseorverticaldirections.Forallothermembers,σyisthedirectstressinthedirectionofthemember’sspan.

5. Considerationistobegiventothecombinedlocalandglobalstressscenario,seeTable4.4.1.6. Thespecifiedvaluesrelatetothemeanshearstressoverthedepthofthemember.Thepeakstressisnottoexceed1.1×

allowablevalue.7. TheeffectofhullgirderstillwaterandwaveshearstressistobeconsideredandaddedtocasesD1toD4.Ingeneral,shear

stressisnottoexceed0,46σL.Forsideshellandlongitudinalbulkheadplatinginwayoftheendsoftransverseoil‐tightbulkheadstringers,theshearstressisnottoexceed0,57σL.


89

PART C:


Chapter 5:

Surge (Fore and Aft) Loading:

Additional Requirements for Fuel Oil Deep Tanks





1.1. ThisChapterisapplicabletocontainershipswhichcarryfueloilindeeptanksconstructedintransversebulkheadstructuresorinacontainercargohold,i.e.fueltankslocatedinboardoftheinnerskin,abovetheinnerbottomandbetweenadjacenttransversebulkheads.

1.2. WherethisanalysisiscarriedoutinPARTAusingafullshipFEmodel,theanalysisinthischaptercanbewaived.


2.1. TheobjectiveofthisChapteristodefinetheloadtobeappliedtotheboundaryoffueloiltanksintheproceduresofPARTAandPARTBduetolongitudinal(surge)acceleration.

2.2. TheinclusionofthisloadcomponentintheproceduresofPARTAandPARTBarenotrequiredforcontainershipshavinglongitudinaldeckgirdersarrangedsuchthatthespanofthecross‐deckboxesdoesnotexceed13m.Thespanofthecross‐deckboxistobecalculatedtakingintoaccountthepresenceofcontinuouslongitudinaldeckgirdersorbulkheads,butignoringendbrackets,etc.Longitudinaldeckgirdersorbulkheadsarenottobeconsideredcontinuousiftheydonotextendoveralengthequivalenttofour40ftcontainerbays.

Section 3: Loadingcondition

3.1. Thisloadingconditionassessestheeffectsoflongitudinalloadscausedbyshipaccelerationsactingonthefueloilinthetank,onthetransversebulkheadandcross‐deckstructures.Thelongitudinalacceleration,ax,atthecentreofgravityofatankistobecalculatedusingthelongitudinalaccelerationformulaegiveninPt3,Ch14,8.2.5oftheRulesforShips.Thefollowingmotioncases,definedinPt3,Ch14,Table14.8.4oftheRulesforShips,aretobeapplied:


90

Headsea: MC1(HS_1) Positivepitchaccelerationcase

MC1(HS_2) Negativepitchaccelerationcase

Obliquesea: MC3(OS1_1) Positivepitchaccelerationcase

MC3(OS1_2) Negativepitchaccelerationcase

NotethatlongitudinalaccelerationduetoMC1(HS_2)isequalinmagnitudetoMC1(HS_1)buttheyareinoppositedirections.Likewise,longitudinalaccelerationsduetoMC3(OS1_1)andMC3(OS1_2)areequalinmagnitudebutoppositeindirection.ThepressureloadatthetankboundaryduetolongitudinalaccelerationistobecalculatedinaccordancewithFig.5.3.1.

3.2. Nootherloadsaretobeapplied.However,ifthehydrostaticpressurecausedbythefueloilwasnotincorporatedintheanalysesofPARTAandPARTB,thiscomponentistobeincludedintheloadcasesdescribedinthisChapter.

3.3. Theeffectofcontainerstacksstowedalongside,inadjacentholdsto,oroverthefueloildeeptanks,aretobeconsideredintheanalysesofPARTAandPARTB.TheseeffectsaretobecalculatedasdescribedinCh2andinPARTB’sanalysis.

Pressureduetonegativelongitudinalacceleration

P=ρl│ax│(N/m2)whereρ=1000kg/m3l=distancefromaftbulkhead(m)

Pressureduetopositivelongitudinalacceleration

P=ρl│ax│(N/m2)whereρ=1000kg/m3l=distancefromfwdbulkhead(m)

Fig.5.3.1

Pressureontankboundariesforfueloildeeptanks

Appendix A Primary Structure of Container Ship, August 2017

91

APPENDIX A:

Procedure to Apply Transverse Asymmetric

Loads to a Half‐Breadth Model

SectionA.1:Proceduretoapplytransverseasymmetricloadstoahalf‐breadthFEmodel

A.1.1 Inordertogenerateatransverseasymmetricloadcaseforahalf‐breadthmodel,itisnecessarytoapplythetransverseloadsbycombiningtwoseparateloadcases.Thesetwoloadcasesconsistof:

1. Thesymmetricloadcase.ThiscaseappliessymmetricloadingcomponentsandboundaryconditionstotheFEmodel,seeFig.A.1.1.

2. Theanti‐symmetricloadcase.Thiscaseappliesanti‐symmetricloadingcomponentsandboundaryconditionstotheFEmodel,seeFig.A.1.1.

A.1.2 Ifanyoftheloadsdonotconformtotheabovedescription,orifthestructureisnotsymmetricaboutthecentreline,thenthistechniqueisnotstrictlyvalidandafull‐breadthFEmodelisrequired.Inthiscase,itmaybenecessarytoconsiderindividualloadcasesforshipheeledinportdirectionandshipheeledinstarboarddirection.

A.1.3 Usingtheabovetwoloadcases,thedifferentstructuralresponseofbothsidesoftheshiptothetransverseloadscanbederivedasfollows:

Portasymmetric = symmetricplusanti‐symmetric

Starboardasymmetric = symmetricminusanti‐symmetric

ThisisillustratedinFig.A.1.1.

A.1.4 Applicationoftheexternalhydrostaticpressurecorrespondingtotheheeledwaterlineforsymmetricandanti‐symmetricloadcasesisillustratedinFig.A.1.1anddescribedasfollows:

1. Thesymmetricloadcomponentforthehydrostaticpressureisappliedashalfthesumofthepressuresontheportandstarboardsides.NoteitisnecessarytomodifythesideshellpressuredistributionasshowninFig.A.1.1tosatisfythesymmetricloaddefinitionstatedabove.

2. Theanti‐symmetricloadcomponentfortheexternalhydrostaticpressureisappliedashalfthedifferenceofpressureontheportandstarboardsides.

A.1.5 Theboundaryconditionsforthesymmetricloadcaseandtheanti‐symmetricloadareasfollows:

1. Symmetricloadcase:SeePARTC,Ch1,Fig.1.5.1.

2. Anti‐symmetricloadcase:SeePARTC,Ch1,Fig.1.5.3.

Appendix A Primary Structure of Container Ship, August 2017

92

Fig.A.1.1

Derivationoftheasym

metricloadcasesforahalf‐breadthmodelfrom

thesymmetricandanti‐sym

metricloadcases(shipheeledcondition)

Appendix B Primary Structure of Container Ship, August 2017

93

APPENDIX B:

Combined Stresses Analysis in Oblique Sea

based on Equivalent Design Waves

SectionB.1 ApplicationB.1.1 WhererequiredbyPt4,Ch8,14.1oftheRulesforShips,thecombinedstressanalysisspecifiedinPARTAandPARTBinobliqueseaconditionistobeanalysedbasedonhydrodynamictorqueandverticalandhorizontalbendingmomentsobtainedbynon‐linearshipmotionanalysis.

B.1.2 IfthehydrodynamicprogramsemployedarenotrecognisedbyLloyd’sRegister,fullparticularsoftheprogramswillberequiredtobesubmittedforreview,seePt3,Ch1,3.1oftheRulesforShips.

B.1.3 InadditiontothecombinedstressanalysisdescribedinthisAppendix,theheadseaconditiondescribedinPARTAandPARTBistobeanalysed.

SectionB.2 LongtermstatisticalanalysisB.2.1 LongtermstatisticalanalysisistobeusedtodeterminethedesignprobabilityleveloftheloadsandtheEquivalentDesignWaves(EDWs)forthecombinedstressanalysis.Theshorttermprobabilityoftheloadresponsesinaparticularseaconditionistobederivedusingaspectralanalysis.Theresponsesinregularwavesmaybeobtainedusinglinearshipmotionanalysisbasedonpotentialflowtheory.

B.2.2 Thefollowingloadingconditionsaretobeanalysed:

afullyloadedconditionwithashipdraughtequalorclosetothescantlingdraught;and

aloadingconditionwithmaximumGM.

B.2.3 ThelongtermanalysisistobebasedontheassumptionsgiveninTableB.2.1andtheNorthAtlanticwaveenvironmentscatterdiagramspecifiedinIACSRec.34giveninTableB.2.2.TheRayleighprobabilitydensityfunctionistobeusedtorepresentthepeakdistribution.Otherprobabilitydensityfunctionsmaybeconsideredinspecialcases.

B.2.4 Thelongtermprobabilitydistributionoftheverticalwavebendingmomentamidshipistobecalculated.Thedesignprobabilityleveloftheloadsinobliqueseaconditionsistobetakenastheprobabilitylevelatwhichthelongtermverticalwavebendingmomentamidshipisequaltothewaveverticalbendingmoment,Mwo,giveninPt4,Ch2,2.4.1(referredtoinPt4,Ch8,3.2)oftheRulesforShips,seeFigureB.2.1.

B.2.5 Thelongtermhydrodynamictorqueattheshearcentrealongthelengthoftheship,at0,05Lppincrements,istobedeterminedattheprobabilitylevelestablishedinB.2.4.Aconstantshearcentreposition,basedontheshearcentreinthemidshipregionatamaximumdistancebelowthebaseline,maybeusedforthecalculationofhydrodynamictorques.

B.2.6 Theequivalentdesignregularwavestoachievethelongtermhydrodynamictorqueatthefollowinglongitudinalpositionsshouldbeconsideredfornon‐linearshipmotionanalysis:


94

Maximumtorqueintherange0≤x<0,5Lpp

Maximumtorqueintherange0,5Lpp≤x≤Lpp

B.2.7 ThewavefrequencyandrelativeheadingofanequivalentdesignwaveistobeselectedsuchthattheResponseAmplitudeOperator(RAO)ofthehydrodynamictorqueisatitsmaximum.ThewaveamplitudeisobtainedbytheratioofthelongtermhydrodynamictorquetotheselectedRAO.Foreachcasetwoequivalentdesignwaves,i.e.wavesapproachingfromtheportsideandstarboardsideatthesameangle,aretobeconsidered.

TableB.2.1 Waveenvironmentandassumptionsforlongtermstatisticalanalysis

Wavedata IACSRec.34,seeTableB.2.2

Waveenergyspectrum

ISSCwavespectrum:

ω 4π1ω

exp16π

ω

Wavespreadingdistribution Cosine‐squared

Directionality(waveheadingrelativetothe

ship)

Allheadingsequallyprobable.Theheadingincrementisnottobegreaterthan

15deg.

Shipspeed 25%oftheship’smaximumservicespeedbutnottobetakenlessthan5knots.

TableB.2.2 IACSRec.34NorthAtlanticwaveenvironmentscatterdiagram

HS/TZ 3,5 4,5 5,5 6,5 7,5 8,5 9,5 10,5 11,5 12,5 13,5 14,5 15,5 16,5 17,5 18,5

0,5

1,5

2,5

3,5

4,5

5,5

6,5

7,5

8,5

9,5

10,5

11,5

12,5

13,5

14,5

15,5

16,5

1,3

0,0

0,0

0,0

0,0

0,0

0,0

0,0

0,0

0,0

0,0

0,0

0,0

0,0

0,0

0,0

0,0

133,7

29,3

2,2

0,2

0,0

0,0

0,0

0,0

0,0

0,0

0,0

0,0

0,0

0,0

0,0

0,0

0,0

865,6

986,0

197,5

34,9

6,0

1,0

0,2

0,0

0,0

0,0

0,0

0,0

0,0

0,0

0,0

0,0

0,0

1186,0

4976,0

2158,8

695,5

196,1

51,0

12,6

3,0

0,7

0,2

0,0

0,0

0,0

0,0

0,0

0,0

0,0

634,2

7738,0

6230,0

3226,5

1354,3

498,4

167,0

52,1

15,4

4,3

1,2

0,3

0,1

0,0

0,0

0,0

0,0

186,3

5569,7

7449,5

5675,0

3288,5

1602,9

690,3

270,1

97,9

33,2

10,7

3,3

1,0

0,3

0,1

0,0

0,0

36,9

2375,7

4860,4

5099,1

3857,5

2372,7

1257,9

594,4

255,9

101,9

37,9

13,3

4,4

1,4

0,4

0,1

0,0

5,6

703,5

2066,0

2838,0

2685,5

2008,3

1268,6

703,2

350,6

159,9

67,5

26,6

9,9

3,5

1,2

0,4

0,1

0,7

160,7

644,5

1114,1

1275,2

1126,0

825,9

524,9

296,9

152,2

71,7

31,4

12,8

5,0

1,8

0,6

0,2

0,1

30,5

160,2

337,7

455,1

463,6

386,8

276,7

174,6

99,2

51,5

24,7

11,0

4,6

1,8

0,7

0,2

0,0

5,1

33,7

84,3

130,9

150,9

140,8

111,7

77,6

48,3

27,3

14,2

6,8

3,1

1,3

0,5

0,2

0,0

0,8

6,3

18,2

31,9

41,0

42,2

36,7

27,7

18,7

11,4

6,4

3,3

1,6

0,7

0,3

0,1

0,0

0,1

1,1

3,5

6,9

9,7

10,9

10,2

8,4

6,1

4,0

2,4

1,3

0,7

0,3

0,1

0,1

0,0

0,0

0,2

0,6

1,3

2,1

2,5

2,5

2,2

1,7

1,2

0,7

0,4

0,2

0,1

0,1

0,0

0,0

0,0

0,0

0,1

0,2

0,4

0,5

0,6

0,5

0,4

0,3

0,2

0,1

0,1

0,0

0,0

0,0

0,0

0,0

0,0

0,0

0,0

0,1

0,1

0,1

0,1

0,1

0,1

0,1

0,0

0,0

0,0

0,0

0,0

NOTES

1. Total100,000waveobservations.

2. HSissignificantwaveheightinmetres.

3. TZiszerocrossingperiodinseconds.


95

Fig.B.2.1

Determinationofdesignloadprobabilitylevelbasedonlongtermprobabilitydistribution

oftheverticalwavebendingmomentamidship

Fig.B.2.2

Selectionoflocationsandtorquefromthelongtermhydrodynamictorqueenvelopecurve,seeB.2.6


96

SectionB.3 Non‐linearshipmotionanalysisB.3.1 Non‐lineartimedomainshipmotionanalysisistobecarriedoutforeachequivalentdesignregularwaveidentifiedinSectionB.2.

B.3.2 Thehydrodynamictorqueattheshearcentre(seeB.2.5)andverticalandhorizontalbendingmomentdistributionsalongtheshiplengthatanincrementnotgreaterthan0,05L,aretobeobtainedforatleast20steps(i.e.0–2π,in0,1πsteps)overacompletewavecycle.

B.3.3 Alternatively,thewavepressuresandinertialloadduetotheshipmotionsmaybeapplieddirectlytotheFEmodeltogeneratetherequiredgloballoads.

B.3.4 Intheselectionofthewavecycle,careistobetakentoensurethatthetimedomainsimulationhasreachedasteadystate.

SectionB.4 CombinedstressanalysisB.4.1 AfullshipFEmodeldevelopedforPARTA’sanalysisistobeusedforthecombinedstressanalysistotheglobalhullstressresponseinobliqueseacondition.TheFEmodel(s)developedforPARTBistobeusedfortheanalysisofgloballoadsonlocalstructuraldetails.AllequivalentdesignwavesidentifiedinSectionB.2aretobeanalysed.

B.4.2 Thedynamicstressresponsesaretobecalculatedforatleast20steps(i.e.0–2π,in0,1πsteps)overacompletewavecycle.Thestressresponsescanbeobtainedbyapplyingthehydrodynamictorque,verticalandhorizontalbendingmomentdistributionsinB.3.2totheFEmodelforeachstepofthewavecycle.Individualloadcomponentsmaybeappliedseparatelyandthecombinedstressesareobtainedbysuperimposition.TheboundaryconditionsgiveninPARTA,Ch1,5forthefullshipmodelcanbeusedforthisanalysis.ForPARTB’sanalysis,additionalboundaryconditionsdescribedinPARTB,Ch1,4aretobeconsideredwhereappropriate.

B.4.3 Alternatively,thestressresponsesmaybeobtainedbyapplyingthewavepressuresandinertialloadduetotheshipmotionstotheFEmodel,seeB.3.3.AsuitableinertialrelieftechniquecanbeusedtobalancetheFEmodel.

B.4.4 PARTAanalysis

ForeachequivalentdesignwaveidentifiedinSectionB.2,thecombinedstaticanddynamicstressesandbucklingfactorsofsafetyoveracompletewavecyclemustcomplywiththecriteria(obliqueseacondition)giveninPARTA,Ch1,6.TheloadcombinationsgiveninPARTA,Ch1,Table1.4.3aretobeconsidered.

B.4.5 PARTBanalysis

ForeachequivalentdesignwaveidentifiedinSectionB.2,thecombinedstaticanddynamicstressesanddynamicstressrangesoveracompletewavecyclemustcomplywiththecriteria(obliqueseacondition)giveninPARTB,Ch1,5.TheloadcombinationsgiveninPARTA,Ch1,Table1.4.3aretobeconsidered.

Appendix C Primary Structure of Container Ship, August 2017

97

APPENDIX C:

Rule Equivalent Design Wave Hydrodynamic

Torque, Vertical and Horizontal Bending

Moment Distributions

SectionC.1 ApplicationC.1.1 Thehydrodynamictorque,verticalandhorizontalbendingmomentsgiveninthisAppendixrepresenttheloadresponsesoftheequivalentdesignwavecorrespondingtothehydrodynamicloadsgiveninPt4,Ch8,15oftheRulesforShips.

C.1.2 TheseloadscanbeusedtodeterminethestructuralresponsesoverawavecyclefortheanalysesinPARTAandPARTB.Theseloadsareequivalenttotheapplicationoftheruleloadformulae.TheprocedureisnecessaryfordeterminingthemaximumvonMisesstressesandminimumbucklingfactorofsafetyoverawavecycle,seePARTA,Ch1,4.6andPARTB,Ch1,4.7.

C.1.3 Thehydrodynamictorque,verticalandhorizontalbendingmomentdistributionsgiveninthisAppendixrepresenttheloadsresultingfromobliqueseastarboardequivalentdesignwave.

SectionC.2 LoadsC.2.1 Theverticalwavebendingmoment,MVWiatstepiofthewavecycleisgivenby:

MVWi =0,0505C0C3,iL2B(Cb+0,7) kNm

=(0,0052C0C3,iL2B(Cb+0,7) tonne‐fm

where

C3,i=VerticalwavebendingmomentdistributioncoefficientsdependingonthelongitudinalpositionfromA.P.giveninTableC.2.1.

OthersymbolsrefertoPt4,Ch8,15oftheRulesforShips.

C.2.2 Thehorizontalwavebendingmoment,MHWiatstepiofthewavecycleisgivenby:

MHWi =0,2063C0C4,iL2T(Cb+0,7) kNm

=(0,0210C0C4,iL2T(Cb+0,7) tonne‐fm

where

C4,i=HorizontalwavebendingmomentdistributioncoefficientsdependingonthelongitudinalpositionfromA.P.giveninTableC.2.2.


C.2.3 Thehydrodynamictorque,MTWiatstepiofthewavecycleisgivenby:


98

MTWi =0,0728C0C5,iLB2(Cb+0,7)–0,8683(0,65T+ε)C0K3,iLT(Cb+0,7) kNm

=(0,0078C0C5,iLB2(Cb+0,7)–0,0886(0,65T+ε)C0K3,iLT(Cb+0,7) tonne‐fm

where

C5,i=HydrodynamictorquedistributioncoefficientsdependingonthelongitudinalpositionfromA.P.giveninTableC.2.3.

K3,i=HorizontalwaveshearforcedistributioncoefficientsdependingonthelongitudinalpositionfromA.P.giveninTableC.2.4.



99

TableC.2.1 Verticalwavebendingmomentdistributioncoefficients

x/LPP ,, ,

, ,, ,

, ,, ,

, ,, ,

, ,, ,

, ,, ,

, ,, ,

, ,, ,

, ,, ,

, ,, ,

,

0,00 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000

0,05 0,062 0,065 0,061 0,051 0,036 0,018 ‐0,002 ‐0,022 ‐0,040 ‐0,054 ‐0,062 ‐0,065 ‐0,061 ‐0,051 ‐0,036 ‐0,018 0,002 0,022 0,040 0,054

0,10 0,158 0,156 0,138 0,106 0,065 0,017 ‐0,033 ‐0,079 ‐0,118 ‐0,145 ‐0,158 ‐0,156 ‐0,138 ‐0,106 ‐0,065 ‐0,017 0,033 0,079 0,118 0,145

0,15 0,305 0,288 0,242 0,173 0,087 ‐0,008 ‐0,102 ‐0,186 ‐0,251 ‐0,292 ‐0,305 ‐0,288 ‐0,242 ‐0,173 ‐0,087 0,008 0,102 0,186 0,251 0,292

0,20 0,460 0,420 0,338 0,224 0,087 ‐0,058 ‐0,197 ‐0,318 ‐0,407 ‐0,456 ‐0,460 ‐0,420 ‐0,338 ‐0,224 ‐0,087 0,058 0,197 0,318 0,407 0,456

0,25 0,611 0,539 0,414 0,248 0,058 ‐0,137 ‐0,319 ‐0,470 ‐0,575 ‐0,623 ‐0,611 ‐0,539 ‐0,414 ‐0,248 ‐0,058 0,137 0,319 0,470 0,575 0,623

0,30 0,732 0,624 0,454 0,240 0,002 ‐0,235 ‐0,450 ‐0,621 ‐0,731 ‐0,769 ‐0,732 ‐0,624 ‐0,454 ‐0,240 ‐0,002 0,235 0,450 0,621 0,731 0,769

0,35 0,817 0,669 0,456 0,198 ‐0,080 ‐0,350 ‐0,585 ‐0,763 ‐0,867 ‐0,885 ‐0,817 ‐0,669 ‐0,456 ‐0,198 0,080 0,350 0,585 0,763 0,867 0,885

0,40 0,850 0,667 0,419 0,129 ‐0,173 ‐0,458 ‐0,699 ‐0,871 ‐0,957 ‐0,950 ‐0,850 ‐0,667 ‐0,419 ‐0,129 0,173 0,458 0,699 0,871 0,957 0,950

0,45 0,836 0,626 0,354 0,048 ‐0,263 ‐0,548 ‐0,780 ‐0,935 ‐0,999 ‐0,965 ‐0,836 ‐0,626 ‐0,354 ‐0,048 0,263 0,548 0,780 0,935 0,999 0,965

0,50 0,780 0,554 0,274 ‐0,032 ‐0,336 ‐0,607 ‐0,818 ‐0,949 ‐0,987 ‐0,929 ‐0,780 ‐0,554 ‐0,274 0,032 0,336 0,607 0,818 0,949 0,987 0,929

0,55 0,683 0,459 0,190 ‐0,097 ‐0,374 ‐0,615 ‐0,796 ‐0,899 ‐0,914 ‐0,839 ‐0,683 ‐0,459 ‐0,190 0,097 0,374 0,615 0,796 0,899 0,914 0,839

0,60 0,555 0,352 0,114 ‐0,135 ‐0,371 ‐0,571 ‐0,714 ‐0,788 ‐0,784 ‐0,704 ‐0,555 ‐0,352 ‐0,114 0,135 0,371 0,571 0,714 0,788 0,784 0,704

0,65 0,415 0,241 0,043 ‐0,159 ‐0,345 ‐0,498 ‐0,602 ‐0,647 ‐0,628 ‐0,548 ‐0,415 ‐0,241 ‐0,043 0,159 0,345 0,498 0,602 0,647 0,628 0,548

0,70 0,275 0,137 ‐0,015 ‐0,165 ‐0,300 ‐0,404 ‐0,470 ‐0,489 ‐0,460 ‐0,386 ‐0,275 ‐0,137 0,015 0,165 0,300 0,404 0,470 0,489 0,460 0,386

0,75 0,165 0,064 ‐0,044 ‐0,147 ‐0,236 ‐0,302 ‐0,338 ‐0,341 ‐0,311 ‐0,250 ‐0,165 ‐0,064 0,044 0,147 0,236 0,302 0,338 0,341 0,311 0,250

0,80 0,085 0,016 ‐0,054 ‐0,119 ‐0,172 ‐0,208 ‐0,224 ‐0,219 ‐0,191 ‐0,145 ‐0,085 ‐0,016 0,054 0,119 0,172 0,208 0,224 0,219 0,191 0,145

0,85 0,041 ‐0,002 ‐0,044 ‐0,083 ‐0,113 ‐0,132 ‐0,138 ‐0,131 ‐0,111 ‐0,080 ‐0,041 0,002 0,044 0,083 0,113 0,132 0,138 0,131 0,111 0,080

0,90 0,022 ‐0,002 ‐0,026 ‐0,047 ‐0,063 ‐0,074 ‐0,077 ‐0,073 ‐0,061 ‐0,044 ‐0,022 0,002 0,026 0,047 0,063 0,074 0,077 0,073 0,061 0,044

0,95 0,010 0,001 ‐0,009 ‐0,017 ‐0,024 ‐0,028 ‐0,030 ‐0,029 ‐0,025 ‐0,018 ‐0,010 ‐0,001 0,009 0,017 0,024 0,028 0,030 0,029 0,025 0,018

1,00 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000

NOTES1. , ,

, where

| | ,, 0,

| | ,, 0

2. , :Hoggingandsaggingverticalbendingmomentcorrectionfactors,see2.1ofINTRODUCTION.3. Intermediatevaluesaretobedeterminedbylinearinterpolation.


100

TableC.2.2 Horizontalwavebendingmomentdistributioncoefficients

x/LPP , , , , , , , , , , , , , , , , , , , ,

0,00 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000

0,05 ‐0,016 ‐0,012 ‐0,007 ‐0,001 0,005 0,010 0,014 0,017 0,019 0,018 0,016 0,012 0,007 0,001 ‐0,005 ‐0,010 ‐0,014 ‐0,017 ‐0,019 ‐0,018

0,10 ‐0,046 ‐0,030 ‐0,010 0,010 0,030 0,046 0,058 0,064 0,064 0,058 0,046 0,030 0,010 ‐0,010 ‐0,030 ‐0,046 ‐0,058 ‐0,064 ‐0,064 ‐0,058

0,15 ‐0,097 ‐0,055 ‐0,009 0,039 0,083 0,119 0,143 0,153 0,148 0,129 0,097 0,055 0,009 ‐0,039 ‐0,083 ‐0,119 ‐0,143 ‐0,153 ‐0,148 ‐0,129

0,20 ‐0,154 ‐0,076 0,009 0,094 0,169 0,228 0,264 0,275 0,259 0,217 0,154 0,076 ‐0,009 ‐0,094 ‐0,169 ‐0,228 ‐0,264 ‐0,275 ‐0,259 ‐0,217

0,25 ‐0,208 ‐0,084 0,049 0,176 0,287 0,369 0,415 0,421 0,385 0,312 0,208 0,084 ‐0,049 ‐0,176 ‐0,287 ‐0,369 ‐0,415 ‐0,421 ‐0,385 ‐0,312

0,30 ‐0,242 ‐0,065 0,118 0,289 0,432 0,533 0,582 0,573 0,509 0,395 0,242 0,065 ‐0,118 ‐0,289 ‐0,432 ‐0,533 ‐0,582 ‐0,573 ‐0,509 ‐0,395

0,35 ‐0,247 ‐0,019 0,211 0,420 0,588 0,699 0,741 0,711 0,611 0,451 0,247 0,019 ‐0,211 ‐0,420 ‐0,588 ‐0,699 ‐0,741 ‐0,711 ‐0,611 ‐0,451

0,40 ‐0,217 0,055 0,322 0,557 0,738 0,846 0,872 0,812 0,673 0,468 0,217 ‐0,055 ‐0,322 ‐0,557 ‐0,738 ‐0,846 ‐0,872 ‐0,812 ‐0,673 ‐0,468

0,45 ‐0,153 0,147 0,433 0,677 0,854 0,948 0,949 0,857 0,681 0,438 0,153 ‐0,147 ‐0,433 ‐0,677 ‐0,854 ‐0,948 ‐0,949 ‐0,857 ‐0,681 ‐0,438

0,50 ‐0,072 0,240 0,528 0,764 0,926 0,997 0,970 0,849 0,644 0,377 0,072 ‐0,240 ‐0,528 ‐0,764 ‐0,926 ‐0,997 ‐0,970 ‐0,849 ‐0,644 ‐0,377

0,55 0,014 0,318 0,590 0,805 0,941 0,985 0,932 0,789 0,568 0,291 ‐0,014 ‐0,318 ‐0,590 ‐0,805 ‐0,941 ‐0,985 ‐0,932 ‐0,789 ‐0,568 ‐0,291

0,60 0,087 0,365 0,608 0,791 0,897 0,915 0,843 0,689 0,467 0,200 ‐0,087 ‐0,365 ‐0,608 ‐0,791 ‐0,897 ‐0,915 ‐0,843 ‐0,689 ‐0,467 ‐0,200

0,65 0,136 0,377 0,581 0,729 0,805 0,802 0,721 0,569 0,361 0,118 ‐0,136 ‐0,377 ‐0,581 ‐0,729 ‐0,805 ‐0,802 ‐0,721 ‐0,569 ‐0,361 ‐0,118

0,70 0,158 0,353 0,514 0,624 0,674 0,657 0,576 0,439 0,258 0,053 ‐0,158 ‐0,353 ‐0,514 ‐0,624 ‐0,674 ‐0,657 ‐0,576 ‐0,439 ‐0,258 ‐0,053

0,75 0,151 0,299 0,417 0,495 0,524 0,502 0,431 0,317 0,173 0,012 ‐0,151 ‐0,299 ‐0,417 ‐0,495 ‐0,524 ‐0,502 ‐0,431 ‐0,317 ‐0,173 ‐0,012

0,80 0,123 0,225 0,305 0,355 0,370 0,349 0,294 0,210 0,106 ‐0,009 ‐0,123 ‐0,225 ‐0,305 ‐0,355 ‐0,370 ‐0,349 ‐0,294 ‐0,210 ‐0,106 0,009

0,85 0,083 0,145 0,193 0,222 0,229 0,214 0,178 0,124 0,059 ‐0,013 ‐0,083 ‐0,145 ‐0,193 ‐0,222 ‐0,229 ‐0,214 ‐0,178 ‐0,124 ‐0,059 0,013

0,90 0,043 0,074 0,097 0,111 0,114 0,106 0,088 0,060 0,028 ‐0,008 ‐0,043 ‐0,074 ‐0,097 ‐0,111 ‐0,114 ‐0,106 ‐0,088 ‐0,060 ‐0,028 0,008

0,95 0,013 0,023 0,031 0,035 0,036 0,034 0,028 0,020 0,009 ‐0,002 ‐0,013 ‐0,023 ‐0,031 ‐0,035 ‐0,036 ‐0,034 ‐0,028 ‐0,020 ‐0,009 0,002

1,00 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000

NOTE1. Intermediatevaluesaretobedeterminedbylinearinterpolation.


101

TableC.2.3 Hydrodynamictorquedistributioncoefficients

x/LPP , , , , , , , , , , , , , , , , , , , ,

0,00 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000

0,05 ‐0,289 ‐0,202 ‐0,096 0,020 0,134 0,235 0,313 0,360 0,372 0,348 0,289 0,202 0,096 ‐0,020 ‐0,134 ‐0,235 ‐0,313 ‐0,360 ‐0,372 ‐0,348

0,10 ‐0,456 ‐0,271 ‐0,060 0,157 0,358 0,525 0,640 0,693 0,677 0,596 0,456 0,271 0,060 ‐0,157 ‐0,358 ‐0,525 ‐0,640 ‐0,693 ‐0,677 ‐0,596

0,15 ‐0,455 ‐0,199 0,075 0,343 0,577 0,754 0,858 0,877 0,811 0,665 0,455 0,199 ‐0,075 ‐0,343 ‐0,577 ‐0,754 ‐0,858 ‐0,877 ‐0,811 ‐0,665

0,20 ‐0,342 ‐0,044 0,258 0,535 0,760 0,910 0,971 0,937 0,812 0,606 0,342 0,044 ‐0,258 ‐0,535 ‐0,760 ‐0,910 ‐0,971 ‐0,937 ‐0,812 ‐0,606

0,25 ‐0,184 0,130 0,432 0,691 0,883 0,988 0,997 0,908 0,730 0,481 0,184 ‐0,130 ‐0,432 ‐0,691 ‐0,883 ‐0,988 ‐0,997 ‐0,908 ‐0,730 ‐0,481

0,30 ‐0,022 0,288 0,570 0,796 0,944 1,000 0,958 0,822 0,606 0,330 0,022 ‐0,288 ‐0,570 ‐0,796 ‐0,944 ‐1,000 ‐0,958 ‐0,822 ‐0,606 ‐0,330

0,35 0,169 0,452 0,691 0,863 0,950 0,944 0,846 0,665 0,418 0,131 ‐0,169 ‐0,452 ‐0,691 ‐0,863 ‐0,950 ‐0,944 ‐0,846 ‐0,665 ‐0,418 ‐0,131

0,40 0,323 0,570 0,761 0,878 0,909 0,851 0,709 0,499 0,239 ‐0,044 ‐0,323 ‐0,570 ‐0,761 ‐0,878 ‐0,909 ‐0,851 ‐0,709 ‐0,499 ‐0,239 0,044

0,45 0,439 0,642 0,782 0,846 0,827 0,727 0,556 0,330 0,072 ‐0,193 ‐0,439 ‐0,642 ‐0,782 ‐0,846 ‐0,827 ‐0,727 ‐0,556 ‐0,330 ‐0,072 0,193

0,50 0,522 0,677 0,766 0,780 0,717 0,585 0,395 0,166 ‐0,078 ‐0,316 ‐0,522 ‐0,677 ‐0,766 ‐0,780 ‐0,717 ‐0,585 ‐0,395 ‐0,166 0,078 0,316

0,55 0,562 0,672 0,715 0,689 0,595 0,443 0,248 0,028 ‐0,194 ‐0,397 ‐0,562 ‐0,672 ‐0,715 ‐0,689 ‐0,595 ‐0,443 ‐0,248 ‐0,028 0,194 0,397

0,60 0,544 0,606 0,609 0,553 0,442 0,288 0,106 ‐0,086 ‐0,271 ‐0,428 ‐0,544 ‐0,606 ‐0,609 ‐0,553 ‐0,442 ‐0,288 ‐0,106 0,086 0,271 0,428

0,65 0,472 0,483 0,447 0,368 0,252 0,111 ‐0,040 ‐0,187 ‐0,316 ‐0,415 ‐0,472 ‐0,483 ‐0,447 ‐0,368 ‐0,252 ‐0,111 0,040 0,187 0,316 0,415

0,70 0,260 0,244 0,204 0,144 0,070 ‐0,011 ‐0,091 ‐0,162 ‐0,217 ‐0,251 ‐0,260 ‐0,244 ‐0,204 ‐0,144 ‐0,070 0,011 0,091 0,162 0,217 0,251

0,75 ‐0,074 ‐0,108 ‐0,132 ‐0,142 ‐0,138 ‐0,121 ‐0,092 ‐0,054 ‐0,011 0,033 0,074 0,108 0,132 0,142 0,138 0,121 0,092 0,054 0,011 ‐0,033

0,80 ‐0,366 ‐0,373 ‐0,344 ‐0,281 ‐0,191 ‐0,082 0,035 0,149 0,248 0,323 0,366 0,373 0,344 0,281 0,191 0,082 ‐0,035 ‐0,149 ‐0,248 ‐0,323

0,85 ‐0,385 ‐0,354 ‐0,288 ‐0,195 ‐0,082 0,039 0,156 0,258 0,334 0,378 0,385 0,354 0,288 0,195 0,082 ‐0,039 ‐0,156 ‐0,258 ‐0,334 ‐0,378

0,90 ‐0,198 ‐0,169 ‐0,124 ‐0,066 ‐0,002 0,062 0,120 0,167 0,197 0,208 0,198 0,169 0,124 0,066 0,002 ‐0,062 ‐0,120 ‐0,167 ‐0,197 ‐0,208

0,95 ‐0,075 ‐0,056 ‐0,031 ‐0,002 0,026 0,052 0,073 0,086 0,091 0,088 0,075 0,056 0,031 0,002 ‐0,026 ‐0,052 ‐0,073 ‐0,086 ‐0,091 ‐0,088

1,00 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000



102

TableC.2.4 Horizontalwaveshearforcedistributioncoefficients

x/LPP , , , , , , , , , , , , , , , , , , , ,

0,00 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000

0,05 0,101 0,061 0,015 ‐0,032 ‐0,076 ‐0,113 ‐0,139 ‐0,151 ‐0,148 ‐0,131 ‐0,101 ‐0,061 ‐0,015 0,032 0,076 0,113 0,139 0,151 0,148 0,131

0,10 0,211 0,107 ‐0,008 ‐0,122 ‐0,224 ‐0,304 ‐0,354 ‐0,370 ‐0,349 ‐0,295 ‐0,211 ‐0,107 0,008 0,122 0,224 0,304 0,354 0,370 0,349 0,295

0,15 0,276 0,112 ‐0,062 ‐0,231 ‐0,377 ‐0,486 ‐0,548 ‐0,555 ‐0,509 ‐0,413 ‐0,276 ‐0,112 0,062 0,231 0,377 0,486 0,548 0,555 0,509 0,413

0,20 0,277 0,060 ‐0,163 ‐0,370 ‐0,541 ‐0,659 ‐0,712 ‐0,696 ‐0,611 ‐0,467 ‐0,277 ‐0,060 0,163 0,370 0,541 0,659 0,712 0,696 0,611 0,467

0,25 0,214 ‐0,045 ‐0,299 ‐0,525 ‐0,699 ‐0,804 ‐0,831 ‐0,776 ‐0,646 ‐0,452 ‐0,214 0,045 0,299 0,525 0,699 0,804 0,831 0,776 0,646 0,452

0,30 0,089 ‐0,181 ‐0,433 ‐0,643 ‐0,790 ‐0,860 ‐0,845 ‐0,748 ‐0,577 ‐0,350 ‐0,089 0,181 0,433 0,643 0,790 0,860 0,845 0,748 0,577 0,350

0,35 ‐0,083 ‐0,326 ‐0,538 ‐0,697 ‐0,787 ‐0,801 ‐0,736 ‐0,599 ‐0,404 ‐0,169 0,083 0,326 0,538 0,697 0,787 0,801 0,736 0,599 0,404 0,169

0,40 ‐0,268 ‐0,459 ‐0,606 ‐0,693 ‐0,712 ‐0,662 ‐0,547 ‐0,378 ‐0,172 0,050 0,268 0,459 0,606 0,693 0,712 0,662 0,547 0,378 0,172 ‐0,050

0,45 ‐0,422 ‐0,526 ‐0,579 ‐0,575 ‐0,515 ‐0,404 ‐0,254 ‐0,079 0,104 0,277 0,422 0,526 0,579 0,575 0,515 0,404 0,254 0,079 ‐0,104 ‐0,277

0,50 ‐0,485 ‐0,489 ‐0,445 ‐0,358 ‐0,235 ‐0,090 0,064 0,212 0,339 0,433 0,485 0,489 0,445 0,358 0,235 0,090 ‐0,064 ‐0,212 ‐0,339 ‐0,433

0,55 ‐0,447 ‐0,353 ‐0,225 ‐0,075 0,083 0,232 0,359 0,450 0,498 0,497 0,447 0,353 0,225 0,075 ‐0,083 ‐0,232 ‐0,359 ‐0,450 ‐0,498 ‐0,497

0,60 ‐0,338 ‐0,172 0,010 0,192 0,355 0,483 0,564 0,589 0,557 0,471 0,338 0,172 ‐0,010 ‐0,192 ‐0,355 ‐0,483 ‐0,564 ‐0,589 ‐0,557 ‐0,471

0,65 ‐0,227 0,011 0,248 0,460 0,628 0,734 0,768 0,727 0,615 0,443 0,227 ‐0,011 ‐0,248 ‐0,460 ‐0,628 ‐0,734 ‐0,768 ‐0,727 ‐0,615 ‐0,443

0,70 ‐0,094 0,193 0,461 0,683 0,839 0,913 0,897 0,794 0,613 0,372 0,094 ‐0,193 ‐0,461 ‐0,683 ‐0,839 ‐0,913 ‐0,897 ‐0,794 ‐0,613 ‐0,372

0,75 0,067 0,372 0,641 0,847 0,970 0,998 0,928 0,768 0,532 0,245 ‐0,067 ‐0,372 ‐0,641 ‐0,847 ‐0,970 ‐0,998 ‐0,928 ‐0,768 ‐0,532 ‐0,245

0,80 0,185 0,470 0,709 0,879 0,963 0,952 0,848 0,661 0,410 0,118 ‐0,185 ‐0,470 ‐0,709 ‐0,879 ‐0,963 ‐0,952 ‐0,848 ‐0,661 ‐0,410 ‐0,118

0,85 0,245 0,487 0,681 0,808 0,857 0,821 0,705 0,520 0,284 0,021 ‐0,245 ‐0,487 ‐0,681 ‐0,808 ‐0,857 ‐0,821 ‐0,705 ‐0,520 ‐0,284 ‐0,021

0,90 0,220 0,403 0,547 0,637 0,664 0,627 0,528 0,378 0,191 ‐0,015 ‐0,220 ‐0,403 ‐0,547 ‐0,637 ‐0,664 ‐0,627 ‐0,528 ‐0,378 ‐0,191 0,015

0,95 0,133 0,227 0,299 0,342 0,351 0,326 0,269 0,186 0,084 ‐0,026 ‐0,133 ‐0,227 ‐0,299 ‐0,342 ‐0,351 ‐0,326 ‐0,269 ‐0,186 ‐0,084 0,026

1,00 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000


Appendix D Primary Structure of Container Ship, August 2017

103

APPENDIX D:

Combined Direct Stresses in Oblique Sea

(Alternative Method)

SectionD.1 ApplicationD.1.1 ThestresscombinationsgiveninthisAppendixcanbeusedasanalternativetoPARTA,Ch1,Table1.4.3toobtainthemaximumandminimumdirectstressesandtangentialstressesifthehydrodynamicloadsinobliqueseaconditionspecifiedinAppendixCareusedintheanalysis.

D.1.2 Thestresscombinationsarenotapplicableifthehydrodynamicloadsinobliqueseaareobtainedusingnon‐linearshipmotionanalysis,seeAppendixB.Inthiscase,theloadcombinationsdescribedinPARTA,Ch1,Table1.4.3aretobeused.

SectionD.2 StressCombinationsD.2.1 ThestresscombinationsaregiveninTableD.2.1.

D.2.2 However,ifnon‐linearshipmotionanalysisisusedtodeterminethehydrodynamicloads,seePARTA,Ch1,4.2,theloadcombinationsgiveninTable1.4.3mustbeused.


104

TableD.2.1 Stresscombinationsforobliqueseacondition(fordirectstresses)

Wave(hullgirder)

Longitudinalacceleration,seeNote1

(Containers,seeNote2

and/orFO,seeNote3)

Stillwater

(seeNote4)

(seeNote6)

Stillwaterhogging

Loadcases

Wavedirection

σ σ σ σ (seeNote5) σ σ

OS1a Starboard σ(OS1a) 1 1 Hog 1

OS2a Starboard σ(OS2a) 1 1 Hog ‐1

OS3a Starboard σ(OS3a) 1 ‐1 Hog 1

OS4a Starboard σ(OS4a) 1 ‐1 Hog ‐1

OS1b Starboard σ(OS1b) ‐1 1 Hog 1

OS2b Starboard σ(OS2b) ‐1 1 Hog ‐1

OS3b Starboard σ(OS3b) ‐1 ‐1 Hog 1

OS4b Starboard σ(OS4b) ‐1 ‐1 Hog ‐1

Loadcases

Wavedirection


OP1a Port σ(OP1a) 1 1 Hog 1

OP2a Port σ(OP2a) 1 1 Hog ‐1

OP3a Port σ(OP3a) 1 ‐1 Hog 1

OP4a Port σ(OP4a) 1 ‐1 Hog ‐1

OP1b Port σ(OP1b) ‐1 1 Hog 1

OP2b Port σ(OP2b) ‐1 1 Hog ‐1

OP3b Port σ(OP3b) ‐1 ‐1 Hog 1

OP4b Port σ(OP4b) ‐1 ‐1 Hog ‐1

Stillwatersagging

Loadcases

Wavedirection


OS5a Starboard σ(OS5a) 1 1 Sag 1

OS6a Starboard σ(OS6a) 1 1 Sag ‐1

OS7a Starboard σ(OS7a) 1 ‐1 Sag 1

OS8a Starboard σ(OS8a) 1 ‐1 Sag ‐1

OS5b Starboard σ(OS5b) ‐1 1 Sag 1

OS6b Starboard σ(OS6b) ‐1 1 Sag ‐1

OS7b Starboard σ(OS7b) ‐1 ‐1 Sag 1

OS8b Starboard σ(OS8b) ‐1 ‐1 Sag ‐1

Loadcases

Wavedirection σ σ σ σ (seeNote5) σ σ

OP5a Port σ(OP5a) 1 1 Sag 1

OP6a Port σ(OP6a) 1 1 Sag ‐1

OP7a Port σ(OP7a) 1 ‐1 Sag 1

OP8a Port σ(OP8a) 1 ‐1 Sag ‐1

OP5b Port σ(OP5b) ‐1 1 Sag 1

OP6b Port σ(OP6b) ‐1 1 Sag ‐1

OP7b Port σ(OP7b) ‐1 ‐1 Sag 1

OP8b Port σ(OP8b) ‐1 ‐1 Sag ‐1

seeContinuationforNotes


105

TableD.2.1 (Continuation):Stresscombinationsforobliqueseacondition(fordirectstresses)

NOTES1. Longitudinalaccelerationloadcomponentisrequiredtobeappliedfortheassessmentoftransversebulkheadandcrossdeck

structures,seePARTA,Ch1,Table1.6.1,andPARTB’sanalysis.2. Containers‐longitudinalcomponentofcontainerloads,arisingfromtheeffectofshipmotions,actingonthetransverse

bulkheadsandcrossdeckstructure.SeePARTA,Ch1,4.3.11andPARTC,Ch2,fordefinitionofthisloadcomponent.3. FO‐longitudinalcomponentoffueloil(orotherliquid)loads,arisingfromtheeffectofshipmotions,actingonthetransverse

bulkheads.SeePARTA,Ch1,4.3.11andPARTC,Ch5,fordefinitionofthisloadcomponent.4. Hoggingandsagging(orminimumhogging)stillwaterloadcasesasspecifiedinPARTA,Ch1,4.3.1and4.3.2aretobe

considered.Thestressofeachstillwaterloadcaseistobecombinedwiththestressesduetocargotorqueandwaveloads(includinglongitudinalaccelerationinertialloadwhererequired,seeNote6)forassessmentagainsttheacceptancecriteria.

5. Inertialforceduetolongitudinalaccelerationofcontainersand/orfueloil,seePARTA,Ch1,4.3.11: 1indicatesapplicationofobliqueseapositivepitchaccelerationcaseMC3(OS1_1) ‐1indicatesapplicationofobliqueseanegativepitchaccelerationcaseMC3(OS1_2)

6. Cargotorqueloadcase,seePARTA,Ch1,4.3.9.

Symbols

σ σ σ σ σ σ σ σ σ σ σ σ

σ σ σ σ

where

σ =Stressduetocargotorque, ,seePARTA,Ch1,4.3.9

σ =StressduetothestillwaterloadcasewithrequiredSWBMdistribution,seeNote4.

σ ,σ =Stressesduetoobliqueseaverticalwavebendingmoments, and ,giveninAppendixC.

σ ,σ =Stressesduetoobliqueseahydrodynamictorques, and ,giveninAppendixC.

σ ,σ =Stressesduetoobliqueseahorizontalwavebendingmoments, and ,giveninAppendixC.

and isequivalenttotheobliqueseaverticalwavebendingmomentsdistribution, and ,giveninPt4,Ch8,15.3.1oftheRulesforShipswiththehoggingandsaggingfactorsincorporated.

and isthesamedistributionastheobliqueseahorizontalwavebendingmoments, and ,giveninPt4,Ch8,15.3.2oftheRulesforShips.

and isthesamedistributionastheobliqueseahydrodynamictorques, and ,giveninPt4,Ch8,15.3.3oftheRulesforShips.

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