基于虚拟激励的滞变支撑耦合结构的随机地震响应分析

Pseudo Excitation Random Seismic Response Analysis for Structures Equipped with Hysteretic Dampers

相邻结构间的滞变支撑连接能有效缓解结构的地震响应。国际上广泛采用基于求解Lyapunov微分方程的随机振动法解决该类问题。Lyapunov法的地震输入局限于散粒噪声,限制了该方法的工程运用。本文假设结构始终保持线弹性,用Bouc-Wen模型模拟非线性滞变恢复力,通过扩阶、降阶矩阵的使用,结合随机等效线性化法,导出滞变支撑连接耦合结构的虚拟激励方程,建立了虚拟激励与响应的关系,形成结构平稳随机地震响应的闭合求解表达式;并基于此方法求解两剪切结构的随机地震响应。数据表明:本文方法与Lyapunov法的计算结果有很好的一致性。随后,采用本文方法分析了滞变支撑在缓解结构地震响应中的作用;基于不同的控制策略,开展了最优初始屈服力的参数研究。

Hysteretic dampers have been widely used in the reactor coolant piping system as the energy absorbing components.In the paper,the random seismic response is evaluated through the pseudo-excitation principle incorporated with stochastic equivalent linearization method without by solving the Lyapunov differential equation for which the seismic excitation at support is limited to be shot noise process.It is supposed that the structures keep elastic and the hysteretic dampers are represented by the versatile Bouc-Wen model.With the aide of assistant matrices,the unidirectional and spatial excitation vectors of three components are derived and a pseudo-excitation closed-form expression for the system random response is established.Consequently,the stationary random seismic response of two shear type structure interconnected with hysteretic dampers is analyzed.The structural root mean square displacement responses for two methods agree well.Meanwhile,the parametric studies for initial yield force of the hysteretic dampers and the optimum way to install the hysteretic damper are discussed.