考虑轴压比影响RC框架-剪力墙结构侧移刚度退化及楼层剪力重分配性能仿真分析

Simulation analysis on lateral stiffness degradation and storey shear force redistribution of RC frame-shear wall structure with different axial compression ratios

采用三维虚拟层合单元非线性有限元分析方法,经对一个两跨四层RC框架分析算例验证后,分别对三种轴压比RC框架和剪力墙抗侧性能进行模拟分析,分析结果表明,轴压比越大侧移刚度退化速率越快;构建三个不同刚度特征值的四层框架-剪力墙结构空间模型并进行抗侧性能仿真分析,发现进入非线性阶段后,框架分担水平剪力比例随水平荷载增大而提高,且结构刚度特征值越大提幅越多,极限荷载时分担比例提至其初始值2倍以上。分析结果还表明,现行规范关于框架-剪力墙结构框架分担楼层剪力的调整规定取值偏低。

The nonlinear finite element method based on degenerated three-dimension solid virtual laminated element theory was used.The validity and efficiency of the method were proved by analysis on a two-span four-layer RC frame model.The lateral performances of RC frame structure and shear wall structure with three axial compression ratios were analyzed respectively by the method.Analysis results show that greater axial compression ratio leads to faster lateral stiffness degradation rate.According to the analysis results,three four-layer RC frame-shear wall structure spatial models with different stiffness characteristic values were built to make lateral performance simulation analysis.Analysis results conclude that after entering the nonlinear phase,RC frame structure shares more proportion of horizontal shear force with increase of horizontal load,the distribution proportion amplitude is also even bigger with increase of structure stiffness characteristic value,and the distribution proportion under ultimate load can become initial value of more than two times.The adjustment value of distribution proportion of storey shear force about the frame structure of RC frame-shear wall structure in Chinese current design codes or specifications is lower than the reasonable value.