timber frame design - woodworks.org · timber engineering is just as much an art as science, one...
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TimberFrameDesign
TheArtofEngineeringanExposedStructure
Disclaimer:ThispresentationwasdevelopedbyathirdpartyandisnotfundedbyWoodWorks ortheSoftwoodLumberBoard.
JimDeStefano,P.E.AIA.F.SEI
“TheWoodProductsCouncil” isaRegisteredProviderwithTheAmericanInstituteofArchitectsContinuingEducationSystems(AIA/CES),Provider#G516.
Credit(s)earnedoncompletionofthiscoursewillbereportedtoAIACES forAIAmembers.CertificatesofCompletionforbothAIAmembersandnon-AIAmembersareavailableuponrequest.
ThiscourseisregisteredwithAIACESforcontinuingprofessionaleducation.Assuch,itdoesnotincludecontentthatmaybedeemedorconstruedtobeanapprovalorendorsementbytheAIAofanymaterialofconstructionoranymethodormannerofhandling,using,distributing,ordealinginanymaterialorproduct.
______________________________Questionsrelatedtospecificmaterials,methods,andserviceswillbeaddressedattheconclusionofthispresentation.
Timberengineeringisjustasmuchanartasscience,onethatisrarelytaughtincollegeorpartofayoungengineer’sprofessionaleducation.Withthispresentation,attendeeshaveanopportunitytolearnfromatimberspecialistinvolvedinawardwinningtimber-frameprojectsthroughoutthenortheast.Topicswillincludethedesignofheavytimbertrusses,glulamelements,joineryandconnections,aswellasexteriorwallsystemsanddesigningforfireprotection.
CourseDescription
LearningObjectives
• Apply the principles of timber truss design.
• Recognize options for timber-frame exterior wall systems.
• Consider basic joinery and connection methods and when to use them.
• Determine how to design timber frames for fire resistance.
Structural EngineeringThe art of molding materials we do not wholly understand into shapes we cannot precisely analyze so as to withstand forces we cannot really assess in such a way that the community at large has no reason to suspect the extent of our ignorance
NewCanaanLibrarycirca1977
SaintJosephChurchcirca1987
SaintPatrickChurchcirca2007
HammerBeamTrussJoinery
HoweTruss
FinkTruss
ScissorTruss
HammerBeamTruss
HammerBeamTrussWestminsterHall
CruckFrame
TheLodgeatCrookedLakeSiren,WI
TheDepotKent,CT
3 Simple Rules for engineering of timber joints
Rule #1
The geometry of the joint should have mating surfaces that allow all structural loads to be transferred in bearing of one member against the other.
TrussHeelJoint
TrussKingPostJoint
Rule #2
The wood removed to create the joint should not unduly weaken the member.
GlulamLayup
Rule #3
Allow for dimension changes due to seasoning of timber. The geometry of the joint should not be altered by shrinkage of the wood and bearing surfaces should remain in tight contact.
TimberRivets
NDS
• TimberSizing• BoltedConnections• TimberRivets
www.timberframeengineeringcouncil.org
Double Shear in Peg
778.0926.01365 BASEPEGV GGF =
MysticSeaportWelcomeCenter
StructuralInsulatedPanels(SIPs)
DesignGuideforSIPsww.sips.org
Structural Behavior
• Deflections often control• Shear deflection is significant• Shear often controls strength• Creep deflection is significant
FireResistanceofMassTimber
AWC-TechnicalReport10
www.awc.org
EffectiveCharLayerThickness
1hour 1.8”1½hour 2.5”2hour 3.2”
MassTimberFirePerformance
• Collapseproceededbyloudcrackingandhissingnoise
• Collapseproceededbylargedeflections
• Steelplateandboltconnectionsfailsuddenly
ProtectSteelHardware
DesignforDurability
KeepYourFeetDry
3DBIM
ThisconcludesTheAmericanInstituteofArchitectsContinuingEducationSystemsCourse
QUESTIONS?
JimDeStefano,P.E.,AIA,[email protected]