《欧规3 钢结构设计》基础教程 教程25计算案例参考文件Word文档格式.docx
- 文档编号:15702814
- 上传时间:2022-11-15
- 格式:DOCX
- 页数:34
- 大小:287.99KB
《欧规3 钢结构设计》基础教程 教程25计算案例参考文件Word文档格式.docx
《《欧规3 钢结构设计》基础教程 教程25计算案例参考文件Word文档格式.docx》由会员分享,可在线阅读,更多相关《《欧规3 钢结构设计》基础教程 教程25计算案例参考文件Word文档格式.docx(34页珍藏版)》请在冰豆网上搜索。
PlasticDesignofPortalframes
ReferencesfortheWorkedExample
Ref1
17.2Plasticdesign-ultimatelimitstate
Thefollowingprocedureissuggested:
1)Defineframegeometry,determineloads,loadcombinations,factorsandfactors(seeSection11).
2)Choosetrialsectionsandtrialhaunchlengthsbyselectingbeamsectionsthathaveresistancesatleastequaltothefollowing:
WherewisthemaximumULSgravityload/unitlengthalongthespanandListhespanoftheportal.
Thehaunchlengthshouldbechosentooptimisetheoverallportalstructure.AlengthofL/10fromthecolumnfaceisareasonableinitialchoice,buttheproportionsofthehaunchgenerallydependofthecharacteristicsofeachindividualbuilding,especiallythesizeoftherafter(seeSection6.3).AhaunchlengthofL/10willnormallyplacethefirsthingeinthetopofthecolumn.Aratherlongerhaunchwillplacethefirsthingeatthesharpendofthehaunch.
3)Calculateframeimperfectionequivalentforces,referringtoENV
1993-1-1Section
5.2.4.3andSection15ofthispublication.Thiscanbebyapreliminaryframeanalysis(whichisnecessaryforallbutthesimplestbuildings)orbyasuitableapproximation.
4)Performplasticanalysisoftheframe(seeSection12.4)assuming:
(a)noreductioninplasticmomentofresistancefromcoexistentaxialandshearforces.Thisapproachmayneedmodifying,whereaxialloadsarehigh,e.g.intiedportals,inportalswithsteepslopesandinportalswithheavyroofingloads.
(b)TrialVSd/Vcr
0,12unlessabetterestimateispossible.
Notethatinupliftcases,themembersmightbesubjecttoaxialtension.Inthiscase,therewillbenodestabilisationoftheframeandVSd/Vcrcanbetakenaszero.
5)CalculateanaccuratevalueofVSd/Vcr.(SeeSection12andAppendixB).
6)If[accurateVSd/Vcr]
>
[trialVSd/Vcr]orifamorerefineddesignisrequired,returntoStep4.
Note:
Forrelativelyslenderframes,itisoftenwisetocheckthedeflectionsattheServiceabilityLimitState,asexplainedinSection
17.4,beforecheckingthebucklingresistance.
7)Forthecolumnscheckthat:
(a)TheclassificationisClass1orClass2asappropriate,asexplainedinSection
13andAppendix
C;
Sections13.1,13.2,13.3andAppendix
C.2areparticularlyrelevant.
(b)Thecrosssectionalresistanceisadequate,asexplainedinSection
Sections
13.4andAppendix
C.4andC.6areparticularlyrelevant.
(c)Theresistanceofthemembertominoraxisbucklingbetweenlateralrestraintsisadequate,asexplainedinSection
D,togetherwiththeappropriatepartsofAppendix
F;
Section
13.5isparticularlyrelevant.
Forelementswithaplastichingewithinthelengthorateitherend,Appendix
D.4shouldbeused(whichcontainsthesamecheckasAppendix
F.4).
Forelementsresistingmomentsandforcesclosetotheplasticresistance,Appendix
D.4mightneedtobeused,becauseAppendix
D.3.4.2cannotbesatisfied.
Forelementswithoutplastichingesandnotveryhighlystressed,Appendix
D.3.4.2shouldbeused,togetherwithAppendix
F.2,withLtakenasthedistancebetweenlateralrestraints,e.g.betweenpurlins.
(d)Resistanceofmembertominoraxisbucklingbetweentorsionalrestraintsisadequate,asexplainedinSection
F.
Themethodofcheckingissimilarto(c)above,butAppendix
F.3shouldbeusedinsteadofAppendix
F.2.
8)Fortherafterscheckthat:
(a)TheclassificationisClass1orClass2asappropriate,asstep7(a)above.
(b)Thecrosssectionalresistanceisadequate,asstep
7(b)above,butwithoutAppendix
C.6.
(c)Theresistanceofthemembertominoraxisbucklingbetweenlateralrestraintsisadequate,asstep
7(c)above.
(d)Theresistanceofthemembertominoraxisbucklingbetweentorsionalrestraintsisadequate,asstep
7(d)above.
9)Forthehaunchescheckthat:
(a)TheclassificationisClass1orClass2asappropriate,asstep
7(a)above,butusingAppendix
EwherethewebslendernessisClass
3.
(b)Thecrosssectionalresistanceisadequate,asstep
7(b)above,butcheckingatseveralcrosssectionswithinthelengthofthehaunch(bothends,quarter,mid-spanandthreequarterpointsarerecommended).Appendix
E.2orAppendix
E.3shouldbeusedwherethewebslendernessisClass
(c)Theresistanceofthemembertominoraxisbucklingbetweenlateralrestraintsisadequate,asStep
7(c)above,butgivingspecialattentiontotheeffectofthetaper.TheseeffectsaredescribedinSection13.5.4,Appendix
D.3.4.2,Appendix
D.5andAppendix
E.4.
(d)Theresistanceofthemembertominoraxisbucklingbetweentorsionalrestraintsisadeq
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- 欧规3 钢结构设计 欧规3 钢结构设计基础教程 教程25计算案例参考文件 欧规 钢结构 设计 基础教程 教程 25 计算 案例 参考 文件