许  浒¹，  余志祥¹，  康翔杰¹，  赵世春^1,2
  （1 西南交通大学土木工程学院，成都 610031；2 抗震工程技术四川省重点实验室，成都 610031）

[摘要] 为了克服现有数值计算模型及算法在模拟多层砌体结构倒塌过程中存在的问题，引入能够考虑脆性材料大变形及塑性损伤的Holmquist-Johnson-Cook（简称HJC）本构模型模拟砌体材料，采用完全连续介质有限元法建立了一栋典型多层大开间砌体结构计算模型，选取经典的E1 Centro波对其进行弹塑性时程分析，基于显式动力积分及自动接触算法，再现了多层砌体结构在地水平震作用下从弹性到破坏，再到倒塌的全过程。通过与实际震害的比较，验证了上述材料模型及数值算法模拟多层砌体结构倒塌破坏的有效性。此外，针对同一结构模型在不同烈度下的破坏形式，探讨了多层砌体结构在特大地震下的倒塌机理及模式，揭示了其因竖向承重构件失效而导致整体结构发生竖向倒塌的本质。最后分析了顶部水平位移、顶部竖向位移及层间位移角限值分别作为倒塌判定指标的适用性。
[关键词] 多层砌体结构；大开间；数值模拟；HJC损伤模型；弹塑性时程分析；倒塌模式
中圈分类号：TU362    文献标识码：A  文章编号：1002-848X(2012) Sl-0220-06

Numerical simulation on collapse process of multistory masonry structure in earthquake
Xu Hu¹, Yu Zhixiang¹, Kang Xiangjie¹, Zhao Shichun^1,2
(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