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1、北京交通大學(xué)碩士學(xué)位論文摘要摘要鋼框架結(jié)構(gòu)在我國高層鋼結(jié)構(gòu)抗震設(shè)計(jì)中廣泛應(yīng)用。本文主要是為了研究一種新型抗震節(jié)點(diǎn).—腹板開洞型節(jié)點(diǎn)的彎矩一曲率關(guān)系,為鋼框架結(jié)構(gòu)在地震作用下的彈塑性反應(yīng)分析做準(zhǔn)備。采用有限元方法進(jìn)行框架結(jié)構(gòu)體系彈性及彈塑性分析的關(guān)鍵步驟是建立單元的剛度矩陣,而單元剛度矩陣的建立關(guān)鍵是彎矩一曲率關(guān)系的確定。本文以桿系有限元為基礎(chǔ),全面而系統(tǒng)的介紹了均質(zhì)材料平面梁柱單元的非線性彈塑剛度矩陣,并用實(shí)體元有限元方法歸納了腹板開洞型節(jié)點(diǎn)的彎矩·曲率關(guān)系。由于線性階段是結(jié)構(gòu)受力進(jìn)入彈塑性階段之前的必經(jīng)階段,也便于對后面內(nèi)容的理解,所以本文首先推導(dǎo)了單調(diào)加載時平面梁柱
2、單元的線性剛度矩陣,然后推導(dǎo)了理想彈塑性模型和雙線性模型的非線性剛度矩陣。對于雙線性模型,先用Clough的雙桿并聯(lián)模型推導(dǎo);再用Otani的串聯(lián)模型,利用彎矩圖面積法推導(dǎo)簡支梁受兩端彎矩作用時的彎矩-曲率關(guān)系,并進(jìn)一步推導(dǎo)其單元彈塑性剛度矩陣。然后總結(jié)了同濟(jì)大學(xué)李國強(qiáng)等人利用塑性鉸法推導(dǎo)單元彈塑性剛度矩陣。基于串聯(lián)模型的方法,推導(dǎo)了三線型模型的彈塑性剛度矩陣,并推廣到多線型和曲線型模型。在理論推導(dǎo)的基礎(chǔ)上,利用ANSYS有限元方法建立了腹板削弱開洞型梁柱節(jié)點(diǎn)和標(biāo)準(zhǔn)型梁柱節(jié)點(diǎn)的有限元模型,總結(jié)了其在單調(diào)加載作用下不同參數(shù)時節(jié)點(diǎn)的彎矩一曲率關(guān)系并和標(biāo)準(zhǔn)型做了比較。[關(guān)鍵詞
3、】:鋼框架結(jié)構(gòu),腹板開洞型節(jié)點(diǎn),彈塑性分析,單元剛度矩陣,ANSYS有限元,彎矩一曲率國家自然科學(xué)基金資助項(xiàng)目,批準(zhǔn)號54278441北京交通大學(xué)碩士學(xué)位論文AbstractSteelmomentframeshavebeenwidelyadoptedintheseismicdesignofhigh-risesteelstructures.Thisarticleistoresearchtherelationshipofthemoment-curvatureofanewmodelcolumn-beamconnection-Steelbeamwithcircularwebop
4、eningsandtomakepreparationsfortheanalysisoftheelasto-plasticresponseofsteelframestructuresubjectedtoearthquakes.It'sthecommittedstepthatbuildinguptheelementstiffnessmatrixtoanalyzetheelasto-plasticresponseofthesteelframestructurebymeansoffinitemethod,andit'sthecommittedstepthatdeterminin
5、gtherelationshipofthemoment-curvaturetobuildinguptheelementstiffnessmatrix.Basedontrussingfinitemethod,thenonlinearelasto-plasticstiffnessmatrixofplanecolumn-beamelementwithhomogeneousmaterialisintroducedgeneralyandsystematicaly,thenthemoment-curvaturerelations吻oftheconnectionwithopening
6、sinthewebisconcludedbymeansofsolidfinitemethod.Becauseit'stheessentialstagethatlinearstagepassbytoentertheelasto-plasticstagewithforceonthestructure,andfortheeasyunderstandingforthenextcontent,firstthelinearstiffnessmatrixoftheplanecolumn-beamelementforaconstantlyincreasingloadisderived,
7、thennextthenonlinearstiffnessmatrixisconcludedwhentheelementiselastic-perfectlyplasticandbilinearmodel.Accordingtobilinearmodels,Clough'sparalelmodelisfirstapplied;ThenOtani'sseriesmodelisintroducedwhichusedmoment-areamethodtodeducethesimplebeam'smoment-curvaturerelations