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許 滸1， 余志祥1， 康翔杰1， 趙世春1,2
（1 西南交通大學(xué)土木工程學(xué)院，成都 610031；2 抗震工程技術(shù)四川省重點實驗室，成都 610031）[摘要] 為了克服現(xiàn)有數(shù)值計算模型及算法在模擬多層砌體結(jié)構(gòu)倒塌過程中存在的問題，引入能夠考慮脆性材料大變形及塑性損傷的Holmquist-Johnson-Cook（簡稱HJC）本構(gòu)模型模擬砌體材料，采用完全連續(xù)介質(zhì)有限元法建立了一棟典型多層大開間砌體結(jié)構(gòu)計算模型，選取經(jīng)典的E1 Centro波對其進(jìn)行彈塑性時程分析，基于顯式動力積分及自動接觸算法，再現(xiàn)了多層砌體結(jié)構(gòu)在地水平震作用下從彈性到破壞，再到倒塌的全過程。通過與實際震害的比較，驗證了上述材料模型及數(shù)值算法模擬多層砌體結(jié)構(gòu)倒塌破壞的有效性。此外，針對同一結(jié)構(gòu)模型在不同烈度下的破壞形式，探討了多層砌體結(jié)構(gòu)在特大地震下的倒塌機(jī)理及模式，揭示了其因豎向承重構(gòu)件失效而導(dǎo)致整體結(jié)構(gòu)發(fā)生豎向倒塌的本質(zhì)。最后分析了頂部水平位移、頂部豎向位移及層間位移角限值分別作為倒塌判定指標(biāo)的適用性。
[關(guān)鍵詞] 多層砌體結(jié)構(gòu)；大開間；數(shù)值模擬；HJC損傷模型；彈塑性時程分析；倒塌模式
中圈分類號：TU362 文獻(xiàn)標(biāo)識碼：A 文章編號：1002-848X(2012) Sl-0220-06Numerical simulation on collapse process of multistory masonry structure in earthquake
Xu Hu1, Yu Zhixiang1, Kang Xiangjie1, Zhao Shichun1,2
(1 The College of Civil Engineering, Southwest Jiaotong University, Chengdu 610031, China; 2 Key Laboratory of Seismic Engineering of Sichuan Province, Chengdu 610031, China)Abstract: In order to overcome difficulties in simulating collapse process of multistory masonry structure by means of available numerical models or algorithm, Holmquist-Johnson-Cook(HJC) damage constitutive model was brought to simulate masonry material taking both large strain and plastic damage into account. A numerical model of the typical multistory large bay masonry structure was built by means of continuum finite element method. Based on explicit dynamic method and automatic contact algorithm, the classic El Centro earthquake data was adopted for elasto-plastic time-history analysis of the model, the entire collapse process of wluch was presented subsequently. By comparing with the practical seismic damage, the material model and numerical algorithm used in this paper were proved to be reasonable. Furthermore, according to different damage modes of the model under different seismic intensity, both destroy mecharusm and collapse modes of multistory masonry structure under great earthquake were analyzed. It is revealed that vertical collapse caused by failure of vertical bearing members was the essential collapse mode of multistory masonry structure. Lastly the top horizontal displacement, top vertical displacement and story drift were used as decision index and were analyzed separately.
Keywords: multistory masonry structure; large bay; numerical simulation; HJC damage constitutive model; elasto-plastic time-history analysis; collapse mode
