rf-/steel aisc

66 Pages·2017·4.08 MB·English

Version
December2018
Add-on Module
RF-/STEEL AISC
DesignofSteelMembers
AccordingtoANSI/AISC360
Program Description
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Contents
Contents
Contents Page
1. Introduction......................................................3
1.1 Add-onModuleRF-/STEELAISC ................................... 3
1.2 UsingtheManual.................................................. 3
1.3 StartingRF-/STEELAISC ........................................... 4
2. InputData........................................................5
2.1 GeneralData ...................................................... 5
2.1.1 UltimateLimitState ............................................... 7
2.1.2 ServiceabilityLimitState .......................................... 8
2.2 Materials .......................................................... 9
2.3 Cross-Sections....................................................11
2.4 IntermediateLateralRestraints ...................................14
2.5 EffectiveLengths-Members .....................................15
2.6 EffectiveLengths-SetsofMembers..............................19
2.7 DesignParameters ...............................................20
2.8 NodalSupports-SetsofMembers ...............................21
2.9 MemberHinges-SetsofMembers ...............................25
2.10 Parameters-SetsofMembers....................................26
2.11 ServiceabilityData ...............................................27
3. Calculation ......................................................29
3.1 DetailSettings....................................................29
3.1.1 UltimateLimitState ..............................................29
3.1.2 Stability ..........................................................30
3.1.3 Serviceability.....................................................31
3.1.4 WarpingTorsion..................................................32
3.1.5 General...........................................................34
3.2 StartingCalculation ..............................................35
4. Results...........................................................36
4.1 DesignbyLoadCase .............................................37
4.2 DesignbyCross-Section..........................................38
4.3 DesignbySetofMembers........................................39
4.4 DesignbyMember ...............................................40
4.5 Designbyx-Location.............................................40
4.6 GoverningInternalForcesbyMember............................41
4.7 GoverningInternalForcesbySetofMembers ....................42
4.8 MemberSlendernesses...........................................43
4.9 PartsListbyMember .............................................44
4.10 PartsListbySetofMembers......................................45
5. ResultsEvaluation ..............................................46
5.1 ResultsinRFEM/RSTABModel ....................................47
5.2 ResultDiagram...................................................50
5.3 FilterforResults ..................................................51
5.4 ModeShapes.....................................................52
6. Printout..........................................................53
6.1 PrintoutReport...................................................53
6.2 GraphicPrintout..................................................54
7. GeneralFunctions...............................................55
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7.1 DesignCases .....................................................55
7.2 Cross-SectionOptimization ......................................57
7.3 UnitsandDecimalPlaces.........................................59
7.4 DataTransfer .....................................................60
7.4.1 ExportingMaterialstoRFEM/RSTAB ..............................60
7.4.2 ExportingEffectiveLengthstoRFEM/RSTAB......................60
7.4.3 ExportingResults.................................................60
8. Example .........................................................62
8.1 DesignValues ....................................................62
8.2 Cross-SectionProperties-W8x28................................63
8.3 MaterialProperties-A992........................................63
8.4 ClassificationofCross-Section....................................64
8.5 DesignforCompression..........................................66
8.5.1 FlexuralBucklingabouty-Axis(MajorPrincipalAxis) .............66
8.5.2 FlexuralBucklingaboutz-Axis(MinorPrincipalAxis) .............67
8.6 DesignforFlexure ................................................68
8.6.1 Flexureabouty-Axis(MajorPrincipalAxis) .......................68
8.6.1.1 Yielding ..........................................................68
8.6.1.2 Lateral-TorsionalBuckling ........................................68
8.6.2 Flexureaboutz-Axis(MinorPrincipalAxis) .......................69
8.6.2.1 Yielding ..........................................................69
8.6.2.2 FlangeLocalBuckling ............................................70
8.7 DesignforCombinedForces .....................................70
A. Literature........................................................71
B. Index.............................................................72
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1 Introduction
1 Introduction
1.1 Add-on Module RF-/STEEL AISC
TheAmericanInstituteofSteelConstruction'sSpecificationforStructuralSteelBuildings[1]describes
thedesignandconstructionofsteelstructuresintheU.S.InthisSpecification,thedesignaccording
totheprovisionsforloadandresistancefactordesign(LRFD)andtotheprovisionsforallowable
strengthdesign(ASD)isregulated. Bothtypesofdesigncanbeperformedwiththepowerful
add-onmodulesRF-STEELAISC(forRFEM)andSTEELAISC(forRSTAB).
Inthefollowing,themodulesofthetwomainprogramsaredescribedinonemanualandare
referredtoasRF-/STEELAISC.
RF-/STEELAISCperformsalltypicaldesignsofstrengthandstability,aswellasforthedeflections.
Theprogramtakesintoaccountvariousloadcombinationsfortheallowablestrengthdesignorfor
theloadandresistancefactordesign.Classifyingsectionsforlocalbucklingintotheappropriate
types(slender,nonslender,compact,noncompact)isimportantforthedesignofmemberssubject
toaxialcompressionand/orflexure.Bythisclassification,theeffectsareaccountedforwherelocal
bucklingreducestheloadcapacity.RF-/STEELAISCdeterminesthelimitingwidth-to-thickness
ratiosofcompressedpartsandcarriesouttheclassificationautomatically.
ForthestabilityanalysisinRF-/STEELAISC,theusercandetermineforeverysinglememberor
setofmemberswhetherbucklingandtorsionalbucklingispossible.Furthermore,theeffective
lengthscanbemodifiedwhendesigningpertheeffectivelengthmethod.Alternatively,thedirect
analysismethodcanbeconsideredwithmemberorsetofmemberstiffnessreductionsinRFEM
orRSTAB.Lateralrestraintsofmembersallowforarealisticrepresentationofthestructuralmodel.
Formodelswithslendercross-sections,theserviceabilitylimitstatehasbecomeanessentialaspect
ofthedesign.ThedeflectionlimitsarepresetaccordingtotheSpecification,butcanbemodified.
Ifnecessary,thereferencelengthsandprecambersofmemberscanbeadjustedaswell.
TheprogramfeaturesanoptiontooptimizesectionsandtoexportthemtoRFEMorRSTAB.By
meansofdesigncases,itispossibletodesignseparatestructuralcomponentsofcomplexmodels
ortoanalyzealternativeswithdifferentsectionsormaterials.
SinceRF-/STEELAISCisintegratedinthemainprogram,thedesignrelevantinputdataispreset
whenthemoduleisopened.Aftertheanalysis,thedesignresultscanbeevaluatedgraphicallyin
theworkwindowofRFEMorRSTAB.Lastbutnotleast,itispossibletokeeprecordsoftheanalysis
intheglobalprintoutreportwhichincludestheinternalforcesandthedesignresults.
WehopeyouwillenjoyworkingwithRF-/STEELAISC.
YourDLUBALteam
1.2 Using the Manual
Topicslikeinstallation,graphicaluserinterface,resultsevaluation,andprintoutaredescribedin
detailinthemanualsofthemainprogramsRFEMandRSTAB.Thepresentmanualfocuseson
typicalfeaturesoftheRF-/STEELAISCadd-onmodule.
Thedescriptionsinthismanualfollowthesequenceandstructureofthemodule'sinputandresult
windows.Inthetext,thedescribedbuttonsaregiveninsquarebrackets,forexample[Viewmode].
Atthesametime,theyarepicturedontheleft.Expressionsappearingindialogboxes,windows,
andmenusaresetinitalicstoclarifytheexplanations.
Attheendofthemanual,youcanfindtheindex.Ifyoucannotfindwhatyouarelookingfor,go
totheKnowledgeBasewhereyoucansearchforthesolutionoftheproblem.OrconsulttheFAQs
onourwebsite.Moreover,thedesignaccordingtoAISCisdemonstratedinarecordedWebinar.
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1 Introduction
1.3 Starting RF-/STEEL AISC
RFEMandRSTABprovidethefollowingoptionstoopentheRF-/STEELAISCadd-onmodule.
Menu
Tostarttheprogramfromthemenubar,select
Add-onModules Design-Steel RF-/STEELAISC.
→ →
Figure1.1:MenuAdd-onModules Design-Steel RF-STEELAISC
Navigator → →
Youcanalsostarttheadd-onmoduleintheDatanavigatorbyselecting
Add-onModules RF-/STEELAISC.
→
Figure1.2:DatanavigatorAdd-onModules RF-STEELAISC
→
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2 InputData
2 Input Data
Whenyouhavestartedtheadd-onmodule,anewwindowappears.Inthiswindow,aNavigator
isdisplayedontheleft. Itmanagesthedifferentwindowthatcanbecurrentlyselected. The
drop-downlistabovethenavigatorcontainsthedesigncases(seeChapter7.1,page55).
Thedesign-relevantdataistobedefinedinseveralinputwindows.WhenyouopenRF-/STEELAISC
forthefirsttime,thefollowingparametersareimportedautomatically:
Membersandsetsofmembers
Loadcases,loadandresultcombinations
•
Materials
•
Cross-sections
•
Effectivelengths
•
Internalforces(inbackground,ifcalculated)
•
Toselectawindow,clickthecorrespondingentryinthenavigator. Tosetthepreviousornext
•
inputwindow,usethebuttonsshownontheleft.Youcanalsousethefunctionkeystoselectthe
next[F2]orprevious[F3]window.
[OK]savestheresults. Thus,youquitRF-/STEELAISCandreturntoRFEMorRSTAB.Toexitthe
add-onmodulewithoutsavinganychanges,click[Cancel].
2.1 General Data
Inthe1.1GeneralDataWindow,youcanselecttheobjectsandtheloadingrelevantforthedesign.
Thetwotabsmanagetheloadcases,loadcombinations,andresultcombinationsforthedifferent
typesofdesign.
Figure2.1:Window1.1GeneralData
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2 InputData
Designof
Figure2.2:Designofmembersandsetsofmembers
ThedesigncanbecarriedoutforMembersaswellasforSetsofMembers. Ifyouwanttodesign
onlyselectedobjects,cleartheAllcheckbox.Thenyoucanaccessthetextboxesandenterthe
numbersoftherelevantmembersorsetsofmembers.The[Delete]buttonclearsthelistofpreset
numbers.The[Select]buttonenablesyoutodefinetheobjectsgraphicallyintheworkwindowof
RFEMorRSTAB.
Whenyoudesignasetofmembers,theprogramdeterminestheextremevaluesoftheanalyses
ofallmemberscontainedinthesetofmembersandtakesintoaccounttheboundaryconditions
ofconnectedmembersforthestabilityanalysis.TheresultsareshowninWindows2.3Designsby
SetofMembers,3.2GoverningInternalForcesbySetofMembers,and4.2PartsListbySetofMembers.
Click[New]tocreateanewsetofmembers.ThedialogboxthatyoualreadyknowfromRFEMor
RSTABappears.Thereyoucanspecifytheparametersofthesetofmembers.
DesignAccordingto
Figure2.3:Designoptions
Thelistboxoptionscontrolwhetherthedesignisperformedaccordingtotheprovisionsforload
andresistancefactordesign(LRFD)ortotheprovisionsforallowablestrengthdesign(ASD).
TherearedesignmethodsavailableforthecurrentversionofANSI/AISC360-16[1]. Ifrequired,
oneofthepreviousversionsofthisSpecificationdatedfrom2010or2005canbeselectedforthe
design.
Comment
Inthistextbox,youcanenternotes,forexampletodescribetheselecteddesignmethodorthe
currentdesigncase.
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2.1.1 UltimateLimitState
Figure2.4:Window1.1GeneralData,tabUltimateLimitState
ExistingLoadCasesandCombinations
Thiscolumnlistsallloadcases,loadcombinations,andresultcombinationsthathavebeencreated
inRFEMorRSTAB.
TotransferselecteditemstotheSelectedforDesignlistontheright,click .Alternatively,you
candouble-clicktheitems.Totransferthecompletelisttotheright,click .
Toselectseveralitemsatonce,clickthemwhilepressingthe[Ctrl]key–ascommonforWindows
applications.
Ifaloadcaseishighlightedinred,itcannotbedesigned.Thishappenswhenaloadcasehasno
loadsorifitcontainsonlyimperfections(seeFigure2.5).
Attheendofthelist,severalfilteroptionsareavailable.Theyhelpyoutoassigntheitemsbyload
case,loadcombination,oractioncategory(e.g.LRFD,ASD).Thebuttonsnexttothetextboxhave
thefollowingfunctions:
Selectsallloadcasesinthelist
Invertstheselectionofloadcases
Table2.1:ButtonsinUltimateLimitStatetab
SelectedforDesign
Thecolumnontherightliststheloadcases,loadandresultcombinationsselectedfordesign.To
removeanitemfromthelist,selectitandclick .Youcanalsodouble-clicktheitem.Totransfer
theentirelisttotheleft,click .
The design of an enveloping max/min result combination, RC, is faster than the design of all
containedloadcasesandloadcombinations.However,theinfluenceofthecontainedactionsis
Resultcombination
difficulttocheckafterwards.
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2.1.2 ServiceabilityLimitState
Figure2.5:Window1.1GeneralData,tabServiceabilityLimitState
ExistingLoadCasesandCombinations
Thissectionlistsallloadcases,loadcombinations,andresultcombinationsthathavebeencreated
inRFEMorRSTAB.
SelectedforDesign
Youcanaddorremoveloadcases,loadandresultcombinationsasdescribedinChapter2.1.1.
ThelimitvaluesofthedeflectionsarepresetintheDetailsdialogbox(seeFigure3.3,page31).To
adjustthosevalues,clickthe[Details]button.
Inthe1.11ServiceabilityDataWindow,youcanspecifythereferencelengthsofthedeflection
analysis(seeChapter2.11,page27).
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2.2 Materials
Thiswindowconsistsoftwoparts:TheuppertablelistsallmaterialscreatedinRFEMorRSTAB.The
MaterialPropertiessectionbelowshowsthecharacteristicsofthecurrentmaterial,i.e.thetable
rowwhichisselectedabove.
Figure2.6:Window1.2Materials
Materialsthatwillnotbeusedinthedesignappeargrayincolor.Materialsthatarenotallowed
arehighlightedinred.Modifiedmaterialsaredisplayedinblue.
Thematerialpropertiesrequiredtodeterminetheinternalforces(MainProperties)aredescribed
inChapter4.3oftheRFEMmanualandChapter4.2oftheRFEMmanual.Thematerialproperties
requiredfordesign(AdditionalProperties)arestoredintheglobalmateriallibrary.Thesevalues
arepreset.
Toadjusttheunitsanddecimalplacesofthematerialpropertiesandstresses,selectSettings
UnitsandDecimalPlacesfromthemenubarofthemodule(seeChapter7.3,page59).
→
MaterialDescription
ThematerialsdefinedinRFEMorRSTABarepreset,butyoucanalwaysmodifythem: Clickthe
materialincolumnA,andthenclickthe buttonorpressthefunctionkey[F7]toopenthe
materiallist.
Figure2.7:Listofmaterials
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