双向水平加载下钢筋混凝土柱抗震性能的数值模拟

Numerical simulation of seismic performance of reinforced concrete columns under biaxial lateral loads

为了研究双向水平荷载作用下钢筋混凝土柱的抗震性能,基于地震工程模拟平台OpenS-ees,采用纤维模型对钢筋混凝土柱空间受力性能进行了数值模拟,模拟结果与已有试验结果吻合较好.在此基础上,讨论了双向水平加载下轴压比、体积配箍率等参数对柱抗震性能的影响规律.结果表明:双向水平加载对柱构件的界限轴压比几乎没有影响,界限轴压比为0.4～0.5;轴压比小于0.1时,柱斜向水平承载力较主轴方向略有提高;在界限轴压比附近,柱斜向水平承载力下降10%左右,主轴方向水平承载力下降幅度达35%左右,同时主轴方向上柱的极限位移角及滞回耗能均随轴压比的增大而显著降低,故实际设计时应充分考虑空间作用对单一主轴方向的不利影响;体积配箍率对柱的延性有较大影响,但对峰值承载力的影响不明显.

To investigate the seismic performance of reinforced concrete（RC） columns under biaxial lateral loads,numerical analysis for tests of RC columns under spatial loads are performed by using the fiber model based on OpenSees software.The simulation results agree well with the test results in literature.The effects of the axial compression ratio and the hoop reinforcement ratio on the seismic performance of RC columns under biaxial lateral loads are analyzed.The analytical results show that biaxial lateral loads have little effect on the critical axial compression ratio,and the value of critical axial compression ratio is between 0.4 and 0.5.The bevel carrying capacity under biaxial lateral loads is greater than that under principal axial loads when the axial compression ratio is less than 0.1.At the critical axial compression ratio,the bevel carrying capacity decreases about 10% while the principal axial bearing capacity decreases about 35%.Moreover,the ultimate displacement angle and the accumulative hysteretic dissipation energy decrease obviously with the increase in the axial compression ratio.Therefore,the adverse influence of special effects on principle axial should be considered in the actual design.The hoop reinforcement ratio has obvious effect on ductility,but it lightly affects carrying capacity.