短肢剪力墙节点扭转性能的有限元分析

Finite Element Analysis of Torsion Performance of Short-Leg Shear Wall Joints

由于混凝土塑性变形的影响,短肢剪力墙节点在受到扭转作用加剧时,与按弹性理论计算的结果相差较大。因此,利用ANSYS有限元计算软件,模拟在水平低周反复荷载作用下的T型短肢剪力墙节点,通过分析其结构变形、裂缝和混凝土应力情况等研究节点的扭转性能。研究结果表明:在梁端施加水平作用力可以对节点造成扭转破坏,且梁与墙连接处因出现应力集中而最先出现裂缝,裂缝出现后因部分混凝土退出工作,节点的受力性能发生质的改变;在一定范围内,适当增加轴压比可以提高短肢剪力墙节点的耗能能力,增加其延性;对于容易受到扭转作用的短肢剪力墙节点,可以适当加强节点配筋布置以承受全部的外扭作用,避免节点被过早破坏。

Due to the plastic deformation of the concrete,when the torsion effect is aggravated of the short-leg shear wall joints,the results of the short-leg shear wall joints are quite different from the results worked out by elasticity theory.Therefore,by using ANSYS finite element calculation software,a simulation test can be done of the T-shaped short-limb shear wall joints under the horizontal low cyclic loading.Based on an analysis of its structural deformation,crack and concrete stress,a study has been carried out of the torsional behaviors of the joints.The research results show that the horizontal force exerted on the beam ends can cause torsional failure to the joints,which will lead to cracks at the connection points between the beams and the walls.Due to the appearance of the cracks,some concrete is out of work,with a qualitative change in the mechanical properties of the joints.Within a certain range,a proper increase in the axial pressure ratio can increase the energy dissipation capacity of the short leg shear wall joints,thus further increasing the ductility of the joints.For short torsional shear wall joints,which are easy to be torsional,the reinforcement layout of joints can be properly strengthened to withstand all external torsion and avoid premature destruction of joints.