摘要
Thisstudyinvestigatedcharacteristicsofbifurcationandcriticalbucklingloadbyshapeimperfectionofspacetruss,whichweresensitivetoinitialconditions.Thecriticalpointandbucklingloadwerecomputedbytheanalysisoftheeigenvaluesanddeterminantsofthetangentialstiffnessmatrix.Thetwo-free-nodesexampleandstardomewereselectedforthecasestudyinordertoexaminethenodalbucklingandglobalbucklingbythesensitivitytotheeigenbucklingmodeandtheanalysesoftheinfluence,andcharacteristicsoftheparametersasdefinedbytheloadratioofthecenternodeandsurroundingnode,aswellasrise-spanratiowereperformed.Thesensitivitytotheimperfectionoftheinitialshapeofthetwo-free-nodesexample,whichoccursduetosnappingatthecriticalpoint,resultedinbifurcationbeforethelimitpointduetothebucklingmode,andthebucklingloadwasreducedbytheincreaseintheamountofimperfection.Thetwosensitivebucklingpatternsofthenumericalmodelareestablishedbyinvestigatingthedisplacedpositionofthefreenodes,andtheasymmetriceigenmodegreatlyinfluencedthebehavioroftheimperfectionshapewhetheritwasatlimitpointorbifurcation.Furthermore,thesensitivemodeofthetwo-free-nodesexamplewassimilartothein-extensionalbasismechanismofasimplifiedmodel.Thestardome,whichwasusedtoexaminetheinfluenceamongseveralnodes,indicatedthattheinfluenceofnodalbucklingwasgreaterthanthatofglobalbucklingastherise-spanratiowashigher.Besides,globalbucklingisoccurredwithreachingbifurcationpointasthevalueofloadratiowashigher,andthebucklingloadlevelwasabout50%-70%ofloadlevelatlimitpoint.
出版日期
2013年03月13日（中国Betway体育网页登陆平台首次上网日期，不代表论文的发表时间）
