双面叠合剪力墙恢复力模型与有限元分析

Restoring force model and finite element analysis of double-sided superimposed shear wall

基于叠合剪力墙在低周反复荷载用下的抗震性能试验,考虑叠合板中预制层和现浇层混凝土强度等级的不同,推导整个受力过程中不同阶段叠合剪力墙顶点位移公式和承载力公式,揭示叠合剪力墙预制层在受力不同阶段参与工作程度,并与试验对比验证公式的合理性。针对叠合面之间的粘结滑移问题,考虑两种极端的情况:叠合面之间完全没有连接和叠合面之间完全连接,推导叠合剪力墙的最大承载力,和试验对比得出叠合面之间不会产生粘结滑移。在理论分析的基础上,基于Open Sees程序,建立叠合剪力墙有限元分析模型,利用理论推导的不同阶段的承载力作为恢复力模型骨架曲线的特征点,考虑刚度退化和混凝土剪力墙在低周反复荷载作用下的捏拢效应,建立叠合剪力墙四线型应力-应变恢复力模型,模拟结果和试验结果对比较为符合,表明提出的叠合剪力墙恢复力模型正确合理。

Based on the seismic performance test of the superimposed shear wall under the low cyclic loading,the different concrete strength grades of precast layer and cast-in-place layer in composite slab were considered,and the formulas of top displacement and bearing capacity of superimposed shear wall at different stages during the whole loading process were deduced,and the degrees of participation of precast layer of superimposed shear wall in different stages of loading were revealed. The rationality of the formula was verified by comparison with the experiment. Aiming at the problem of bond-slip between overlapping surfaces,two extreme cases were considered: no connection between overlapping surfaces and complete connection between overlapping surfaces. The maximum bearing capacity of superimposed shear walls was deduced,and no bond-slip between overlapping surfaces was obtained by comparison with test. On the basis of theoretical analysis and Open Sees program,the finite element analysis model of superimposed shear wall was established. Taking the bearing capacity of different stages as the characteristic points of the skeleton curve of the restoring force model,considering the stiffness degradation and the reduced pinch phenomenon of the concrete shear wall under low cyclic loading,a four-line stress-strain restoring force model of the superimposed shear wall was established. The simulation results were in good agreement with the experimental results,which shows that the proposed restoring force model for superimposed shear wall is correct and reasonable.