轴压比对RC剪力墙剪切破坏尺寸效应影响的细观分析

剪切破坏是剪力墙破坏的主要模式之一，借助细观数值分析方法对高宽比为1.0的钢筋混凝土(RC)剪力墙的破坏行为进行了分析，研究了轴压比对不同尺寸剪力墙的破坏模式、抗剪承载力、延性、耗能能力等性能的影响，分析了剪力墙剪切破坏的尺寸效应行为，并揭示了轴压比对名义抗剪强度尺寸效应的影响规律。结果表明:不同轴压比作用下的RC剪力墙均发生了明显的剪切破坏，且破坏模式一致；轴压比增大，剪力墙抗剪承载力提高，但延性降低，变形能力下降；随剪力墙尺寸的增大，其名义抗剪强度降低，即存在明显的尺寸效应；轴压比越大，剪切破坏更具脆性，尺寸效应更明显；当剪力墙长度大于1600 mm后，其名义抗剪强度趋于稳定值，尺寸效应逐渐消失。

INFLUENCE OF AXIAL COMPRESSION RATIO ON SIZE EFFECT OF RC SHEAR WALL UNDER SHEAR FAILURE: MESO-SCALE SIMULATION

Shear failure is one of the main failure modes of shear walls. The failure behavior of reinforced concrete (RC) shear wall with aspect ratio of 1.0 is analyzed by means of meso-scale numerical analysis. The influences of axial compression ratio on failure mode, shear bearing capacity, ductility and energy dissipation capacity of shear walls with different sizes are studied. The size effect in shear failure of shear wall is analyzed, and the influence of axial compression ratio on the size effect of nominal shear strength is also revealed. The results indicate that all the simulated RC shear walls with different axial compression ratios exhibit obvious shear failure. When the axial compression ratio increases, the shear bearing capacity of shear wall increases, but the ductility and the deformation capacity decreases. With the increasing size of shear wall, its nominal shear strength decreases, that is, there is an obvious size effect. The greater the axial compression ratio is, the more brittle the shear failure is and the more obvious the size effect is. And when the length of shear wall is greater than 1600 mm, its nominal shear strength tends to be constant, and the size effect gradually disappears.