HSSDesignwiththeLatestCodesandMaterialSpecifications

KimberleyOlson,PETechnicalConsultanttotheSteel

TubeInstitute

Topics

UsesMaterialsAvailabilityConnections

Structuralmembershavebeenaroundforcenturies.Theyvebeenusedasflexuralloadcarryingmembersascolumnsandbeamsinhutsandhousingandforscaffolding.

Galileostudiedstructuralmembersinthe15thcentury.Hecalledthemhollowsolidsandanalyzedspecificexamplesfromnature thestemsofflowersthebonesofanimalsbamboostructuralmemberswhicharelightweightandflexible,yetstrong.

History

Compression

Noweakaxis greatforcolumns

Torsion

TorsionalconstantofanHSSis200timesthatofanopensection

HSS Wide Flange

Torsion

TorsionExample:Beamlength30torsionalload1.2ftk/ft

W18x35=2.41rad

HSS12x6x5/16=0.0063rad

BlastLoading

HSSaregoodblastresistantmembers directionofloading highertorsionalrigidity compositeHSSmembers

ManufacturingProcess

Twoprocesses: ElectricResistanceWelding(ERW) Weld Round,Form SquareProcess(continuousforming)

Form Square,Weld SquareProcess(directforming)

SubmergedArcWelding(SAW)

ManufacturingProcess

Allstartswhensteelcoilsaresplitintoproperwidths

Weld Round,Form Square

Form Square,Weld Square

SubmergedArcWelding

HSSMaterials

A500A1085A1065A847A53A252

hasbeenaroundsincethelate70s

ASTMA500

ExcerptfromASTMA50013

ASTMA500

The0.93ReductionSpec Design wall thickness

Supporting Manual Designation Comments

1989 ASD (1) tnom 9th Ed. ASD TS

1986 LRFD tnom 1st Ed. LRFD TS

1993 LRFD (2) tnom 2nd Ed. LRFD TS

1997 HSS (LRFD) 0.93 x tnom (3) NA (4) HSS

Supplement to the 1993 LRFD Spec.

1999 LRFD (2) 0.93 x tnom (3) 3rd Ed. LRFD HSS

2000 HSS (LRFD) 0.93 x tnom (3) 3

rd Ed. LRFD HSS Supplement to the 1999 LRFD Spec.

2005 (AISC 360-05)

ERW: 0.93 x tnomSAW: tnom 13

th Ed. HSS

2010 (AISC 360-10)

ERW: 0.93 x tnomSAW: tnom 14

th Ed. HSS

2016 (AISC 360-16)

A500: 0.93 x tnomA1085*: tnom 15

th Ed. HSS * also includes A1065

Notes:(1) Includes previous ASD specifications and Manuals. HSS was not specifically covered in all of these specifications or manuals (2) The reduction is included by using the appropriate separate HSS Specification(3) Applies when the actual thickness of the wall is not known(4) This specification never appeared in the Manual of Steel Construction but it did appear in the HSS Connections Manual.

ASTMA1085

YieldStrengthWallThickness

tolerance&Masstolerance

CornerRadius

A500

holdon,ihavetolookitup

rangesfrom3350ksi

10%nomasstolerance

0.41.8t 3t

The0.93Reduction

ASTMA1085 0.93factornotrequired!! NotinAISC360yetbuthasbeenpublishedinModernSteel

AISC36016draftincludesA1085anddoesnotrequirethicknessreduction

StrengthComparisonCompressivestrength:HSS6x6x3/8,kL=14

A500GrB A1085

Fy =46ksi Fy =50ksi

Pn =153k Pn =172k

0.93xtnom tnom

12%increase

ASTMA1085Ry valueswillgodown

Ry =actualyieldspecdminyield

ASTMA1085Steelsforuseinprimarybridgemembersarerequiredtohavesufficientfracturetoughnesstoreducetheprobabilityofbrittlefailureinthepresenceofafatiguecrackorothernotchlikedefect.CVNtestrequirement

Abilityofamaterialtoresistfractureunderimpactloading

Measuresabsorbedenergyduringfracture CutVinsteelandhitwithapendulum,measurehowfarthependulumswingsup

Amountofenergyabsorbedwillincreaseastemperatureincreases

ASTMA1085AASHTOdividesUSintothreetemperaturezonesforspecifyingfracturetoughness.Delineatedbylowestanticipatedservicetemperature

A1065SAWmanufacturingprocess

onlyrectangular/squaresections

taperedsections

largersections(perimetergreaterthan64andupto1thick)

noreductionindesignthickness

A500GrBvsGrCSmackdown

DUALCERT!!!AlwaysspecifyGradeC!

TheSeamWeldPerA500,Thelongitudinalbuttjointofweldedtubingshallbeweldedacrossitsthicknessinsuchamannerthatthestructuraldesignstrengthofthetubingsectionisassured

A50013addsthattheweldseamshallnotbeplacedwithintheradius

ASTMA53

Atruepipespecification,intendedformechanicalandpressureapplications(steam,water,air,gas).NotrecommendedbySTI.

Availability

ConnectionsProgram WF bm to

HSS colHSS Col splices

HSS Col base plate

HSS vert bracing

HSS to HSS (truss)

Mitered Knee / End pl

Integration

Enercalc X None

DESCON X X None

Fastrak Connection

X Fastrak

LIMCON X X X X X None

RAM Connection

X X X X RSS, RE, STAAD

RISA Connection

X X RISAFloor & RISA-3D

SDS/2 Connect

X X X X REVIT 2014 add-in

STIs HSS Connex Online

None checks HSS support only

TEDDS X None STI development

Connections TEDDS

Connections TEDDS

Connections Excel

SinglePlateShearConnectionofWFBeamtoHSSColumnMomentConnectionofWFBeamtoHSSColumn ContinuousBeamoverColumn ThroughPlate DirectlyWelded

TrussConnection KConnection T/YConnection

Connections Excel

Connections HSSConnexOnline

ProprietaryConnections

Sideplate ConXtech

ProprietaryConnections

CastConnexHolloBolt*by

Lindapter,BlindBolt,BoxBoltbyLNA*

Resources

AISCManual&DesignGuide24 CIDECTDesignGuides HollowStructuralSectionConnectionandTrusses byJ.A.Packer&J.E.Henderson

STIsContactpage ComingQ1/2015STIProductManual

Thankyou!!

KimOlson,PE303.720.4076

kim@forseconsulting.com