滞变智能隔震结构的序列最优控制算法

Sequential optimal control algorithm for hysteretic smart isolated structures

将地震波简化为一系列脉冲,在每个时间步长上重新构造控制目标函数,建立了一种新的时域内的结构振动最优控制算法,并在滞变模型的智能隔震结构中用状态转移法加以实现。文中采用Bouc-Wen模型描述结构恢复力,并利用等效线性化方法处理非线性运动方程,分别导出了状态反馈和输出加权的两种表达式。文末选用作者承担设计过的实际隔震建筑中的一个单体工程作为算例,比较了输入三种不同地震波时各种算法的控制效果。结果表明,在相同控制能量下,本文算法对滞变结构能有效地削减响应峰值,综合性能优于现有的两种时域内的结构最优控制算法。

This paper presents a new algorithm for optimal control of hysteretic structures subjected to earthquake excitation. The earthquake signal is discretized into a series of pulse excitation, and the control objective function is reconstructed at each time step. The structure is modeled as Bouc-Wen hysteretic model, and equivalent linearization technique with assumption of zero hysteretic component is used to deal with the nonlinear equation of motion. A new algorithm for optimal control of structural vibration is proposed in time domain based on the idea of sequential optimal control (SOC) which was developed by the auther for linear isolated structures. The SOC for hysteretic smart isolated structure is realized using state transition approach, and two formulae have been derived for both cases of state feedback and output weighted control. An actual isolated building, which was designed by the author's group, has been used as numerical example at the end of the paper, and the control effect of various algorithms is compared with three different earthquake waves. The result shows that the proposed SOC algorithm is advantageous over the degraded classical optimal and instantaneous optimal control algorithms in that the SOC can suppress the peak response more efficiently with less increase of dynamic response in the superstructure, and has a better stability.