woodworks presenta€¦ · shear transfer scenarios will also be discussed. ... • if interior...
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Pleaseaddrelevantlogohere
WoodworksPresenta.on
PresentedbyNormanScheel,P.E.,S.E.,SECB,F.SEAOC,F.ASCE,LEEDAPBD+C,LEEDAPHOMES
Disclaimer:Thispresenta1onwasdevelopedbyathirdpartyandisnotfundedbyWoodWorksortheSo=woodLumberBoard.
WoodworksPresenta.on
PresentedbyNormanScheel,P.E.,S.E.,SECB,F.SEAOC,F.ASCE,LEEDAPBD+C,LEEDAPHOMES
“TheWoodProductsCouncil”isaRegisteredProviderwithTheAmericanInsKtuteofArchitectsConKnuingEducaKonSystems(AIA/CES),Provider#G516.Credit(s)earnedoncompleKonofthiscoursewillbereportedtoAIACESforAIAmembers.CerKficatesofCompleKonforbothAIAmembersandnon-AIAmembersareavailableuponrequest.
ThiscourseisregisteredwithAIACESforconKnuingprofessionaleducaKon.Assuch,itdoesnotincludecontentthatmaybedeemedorconstruedtobeanapprovalorendorsementbytheAIAofanymaterialofconstrucKonoranymethodormannerofhandling,using,distribuKng,ordealinginanymaterialorproduct.__________________________________
QuesKonsrelatedtospecificmaterials,methods,andserviceswillbeaddressedattheconclusionofthispresentaKon.
CourseDescrip.on
ThiscourseisintendedforengineersandarchitectswhospecifymetalplatedwoodtrussesforuseincommercialandmulK-familybuildingprojects.Metalplateconnectedwoodtrusses(MPCWT)havelongbeenusedasacosteffecKvemethodtoachievelongspansinroofandfloorapplicaKons.ThispresentaKonwillcoversharedresponsibiliKesbetweenthedesignprofessionalofrecordandthetrussdesigner:theproperspecificaKonofdesignloads,includingexamplesoftrussesusedasdiaphragmchords,andshopdrawingreviews.Bracing,largecanKlevers,over-framing,secKonaltrusses,andsheartransferscenarioswillalsobediscussed.
LearningObjec.ves
1.Reviewthestandard-of-pracKceforsharedresponsibilityoftrussdesignbetweenthedesignprofessionalofrecord,responsibleforthebuildingasawhole,andthetrussmanufactureranddesignerprovidingstructuralcomponentsusedinthebuilding.2.OutlinecriKcalandusefulinformaKontoincludeinbuildingconstrucKondocumentstoimprovetrussmanufacturersabilitytodeliverhighperformingcomponents.3.OverviewhowtoreadtrussshopdrawingstoverifyconformancewiththeintendedspecificaKons.4.ExaminedifferentconfiguraKonsandtrussdetailstodemonstratehowmetalplateconnectedwoodtrussescanmeettheneedsofavarietyofbuildingprojects.
• DesignResponsibili.es
• DesignLoads• Ver.calLoads• LateralLoads(wind&seismic)
• Sheartransfer(collectors)• Chords
• Bracing• Webs• Chords(T.C.&B.C.)• Overframing• Sec.onalTrusses• GableEndBracing
• ShopDrawings• Layouts• TrussDrawings
• SpecialUses• TrussMyths
CourseOutline
Construc.
on
Documents
CodeDefinedTerms
Contractor
TrussDesignDrawing
TrussDesignEngineer
TrussDesigner
RegisteredDesignProfessional
TrussManufacturer
TrussPlacementDiagram
TrussSubmi<alPackage DeferredSubmi<als
IndicatesLicensedPersons
* *
*
*
• LoadsappliedtoTrusses
• TrussReac.ons
ImportantforEORReview
• GableEndBracing
• EndWallBracing
• PermanentWebBracingRestraint
• UpliWConnec.ons
• LateralLoadConnec.onstoTopPlates
• TrussHangerstoGirders
• TrussHangerstoBeams
• GirdertoGirderHangers
• Overframing&TopChordBracing
Addinteriorbearings,notsosimple.Ifnotdesigned,supportsmaybeinthemiddleofpanelsornearajoint.
SimpleCase
PreliminaryDesign
Max.Span=60’
Min.Depth(in.)=Span(W.)–10
FlatTrusses
Examples:
40’span,min.30”deepaverage
50’span,min.40”deepaverage
60’span,min.50”deepaverage
SlopingFlatshaveheelheightover21”
Es.ma.ngDeflec.ons&InteriorReac.ons
TreatasBearing–
UseMomentofIner.a(I)foreffec.vedepthfordeflec.on
Deflec.onvs.LoadGraph0 1.580 0.800 0.410 4166 8333
500 1.180 0.680 0.3501000 0.780 0.560 0.2901500 0.390 0.440 0.2302000 0.070 0.320 0.200
1250
K=STIFFNESS (LBS./IN.)
DBL. HOWE TRUSS (4/12)
DBL. HOWE TRUSS (6/12) FLAT TRUSS
DL+LL DEFLECTION (IN.)
LOAD (LBS.) DBL. HOWE TRUSS (6/12) FLAT TRUSS DBL. HOWE
TRUSS (4/12)
DEFLECTION VS. LOAD
1.580
1.180
0.780
0.390
0.070
0.800
0.680
0.560
0.440
0.320
0.4100.350
0.2900.230 0.200
0.000
0.200
0.400
0.600
0.800
1.000
1.200
1.400
1.600
1.800
0 500 1000 1500 2000
CONCENTRATED LOAD (LBS.)
DEF
LEC
TIO
N (L
L +
DL)
Flat Truss Dbl. Howe Truss (4/12 Pitch) Dbl. Howe Truss (6/12 Pitch)
ForGableTruss,usesameasFlatTrussanduse0.8overalleffec.vedepth
Example:
40’span,4/12pitch
0.8xdepth=0.8x4x20=64”
Resultsarewithin10%forDeflec.onsandReac.ons.ThisisOKforPreliminaryDesign.
Reasons:
• Deflec.onsaresmall
• BeamReac.onsareapproximateifTrussiscon.nuous
1.22.848
-0.48.4815
0.587.5814
1.46.6813
2.06.0812
2.05.0711
1.84.2610
1.53.559
0.82.237
0.41.626-0.21.215-0.80.804
DifferenceDeadLoadSlopeIncrease(14PSF)
LiveLoadDecrease
Slope/12
TrussMyths
• Thetrusscompanyhandleseverythingfromthetopplateup.
• Beamsbelowtrussesprovidetheinfinitelyrigidsupportasmodeledinthecomputeranalysis.
• Axialforcesintrussmembersareatthemembercenterlines.
• Thepin/rollermodeledinthecomputerisaccurate.
TrussMyths
• Trussjointsareall“pin”connected.
• Theengineerwhosealedthetrussdrawingshasseentheplans.
• Thedesignprofessionalwillincorporatethetrussdesignsintothebuildingdesign.
• Ifinteriorwallstouchthebo<omchorditwilloverstressthemembers.
TrussMyths
• Collectortrusses(sheartransfertrusses)atthegableendneedtobestructural(withwebinsteadofver.calsonly)ifthetrusshasheelsateachend.
• Scissortrussesimposelateralloadsontheexteriorwallsattheheels.
• Alevelreturnwillsupporttheendofalongoverhang.
Ques.ons?ThisconcludesTheAmericanInsKtuteofArchitectsConKnuingEducaKonSystemsCourse