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1、摘要框架節(jié)點(diǎn)是指框架梁及框架柱相交的節(jié)點(diǎn)核心區(qū)與鄰近核心區(qū)的梁端及柱端。它是結(jié)構(gòu)傳力的樞紐,主要是通過斜壓柱機(jī)構(gòu)和桁架機(jī)構(gòu)以及箍筋的“約束機(jī)制’’作用來承受梁柱端傳來的剪力作用。節(jié)點(diǎn)的變形主要由節(jié)點(diǎn)的剪切變形和粱縱筋滑移所產(chǎn)生的轉(zhuǎn)角組成。而本文主要考慮節(jié)點(diǎn)剪切變形影響,對于節(jié)點(diǎn)滑移影響可通過對本節(jié)點(diǎn)模型的剪切剛度修正來加以考慮。當(dāng)結(jié)構(gòu)處于彈性受力狀態(tài)時,節(jié)點(diǎn)剪切變形所引起的變形在框架結(jié)構(gòu)整體變形中所占比例較小,但是當(dāng)框架結(jié)構(gòu)在地震作用下進(jìn)入彈塑性狀態(tài)時,由節(jié)點(diǎn)變形所引起的變形在結(jié)構(gòu)整體變形中比重不
2、容忽視,尤其是未經(jīng)過抗剪強(qiáng)度驗(yàn)算的或承受較大剪壓比的節(jié)點(diǎn)。目前大多數(shù)在進(jìn)行結(jié)構(gòu)抗震分析和計(jì)算時,都假定節(jié)點(diǎn)是剛性節(jié)點(diǎn),實(shí)際上完全剛性的節(jié)點(diǎn)是不存在的,尤其對地震作用下的復(fù)雜受力情況。因此,考慮節(jié)點(diǎn)剪切變形的影響顯得很重要。對此,本文基于Takeda剛度退化三線性模型基礎(chǔ)理論,并根據(jù)大量參考文獻(xiàn)資料,建立了符合節(jié)點(diǎn)受力過程的剪力與剪切變形的三線段滯回曲線模型。節(jié)點(diǎn)剪切變形模型考慮了混凝土強(qiáng)度、軸壓比、剪壓比、配箍率四個因素。根據(jù)以上節(jié)點(diǎn)單元模型分析,本人應(yīng)用Fortran語言編制了相應(yīng)的節(jié)點(diǎn)單元模塊
3、程序,并與本人導(dǎo)師王依群所編制的NDAS2D軟件相接,對一些低周反復(fù)加載試驗(yàn)的框架結(jié)構(gòu)試驗(yàn)?zāi)P瓦M(jìn)行驗(yàn)算。通過對比分析表明,該程序模塊試驗(yàn)現(xiàn)象和過程基本符合。關(guān)鍵詞:地震作用,框架節(jié)點(diǎn),抗剪,剪切變形,滯回曲線ABSTRACTBeam-columnjointiscomposedofcoreofjointandbeam-columnadjacent.Jointisthehingefors仇lctureofRC缸ffnetotransferforces,anditdependsonthetruss,th
4、ediagonalstrutmechanismsandtheconfinementmechanismtoresistshearforcetransferredfrombeamandcolumn.Jo缸deformationcontainssheardeformationandsnpoflongitudinalreinforcementpassingthroughjoint.Butinthispapersheardeformationismainlytakenintoaccount,andslipo
5、flongitudinalreinforcementpassingthroughjointisconsideredjustbymodifyingitsrigidmatrixofthejointshearelementwhenitseffctisimportant.111edeformationcausedbysheardeformationhaveasmallproportionofthetotaldeformationofsla'ucturewhenitisonelasticstate,buth
6、avealargeproportionwhenitisonelastic-plasticstateespeciallyforthejointswhichdon’tbecheckedfortheirseismicshearorendurehighratioofshearforcetoconcretecompressiveforce.Atpresent,jointisgenerallyconsideredrigidwhenWehaveaanalysisandcalculationonseismicsh
7、earofjoint.Infact,theabsoluterigidjointisimpossible;especiallywhenjointisenduretheeffctofseismicforces.Soitisveryimportanttoconsidertheeffectofjointsheardeformationonstructure.Inthispaper,theresiliencemodelbetweenjointshearforceandjointsheardeformatio
8、nisestablishedon也ebaseof也emodelofTekedaandalotofreferenceanddata.Fourfactorsthatconcreteintensity,axialcompressionratio,shearcompressionratio,hoopreinforcementratioareconsideredinthemodelofjointsheardeformation.Fortheaboveresiliencemodelofjoin