自复位单自由度体系随机地震响应分析

A random seismic response analysis of self-centering SDOF systems

给出了自复位体系恢复力的数学描述,建立了正态白噪声地面激励下采用等价线性化法求解自复位单自由度体系随机响应的流程,并采用Monte-Carlo法验证了其正确性,最后通过参数分析对随机响应的影响因素进行了研究。结果表明:结构周期越小,屈服位移系数或耗能参数越大,体系位移方差系数和速度方差系数越小;结构屈服后刚度系数越大,位移方差系数越小,速度方差系数越大;结构周期越大,屈服位移系数、屈服后刚度系数和耗能参数对位移方差系数和速度方差系数的影响越大。

In this work,the mathematical expression of restoring force of a self-centering system was given.The procedure of solving the random responses of self-centering SDOF（single degree of freedom）system under normal white noise ground excitation was established,which was compared and verified using the Monte-Carlo simulation method. Finally,the factors influencing the random responses were investigated by parametric analyses.The results indicate that the smaller structure period,the larger yield displacement ratio,or energy dissipation parameter leads to smaller displacement variance ratio and velocity variance ratio. With the rise of post-yielding stiffness coefficient, the displacement variance ratio decreases whereas the velocity variance ratio increases.For larger structure period,the yield displacement ratio,the post-yielding stiffness coefficient or energy dissipation parameter exerts greater impact on the displacement variance ratio or the velocity variance ratio.