Abstract:The physically-motivated stochastic optimal control has been proved to be efficient in performance improvement and risk mitigation of engineering structures. In this paper, the polynomial control method in context of the physical scheme ruling nonlinear stochastic systems is re-visited, of which time-variant gain parameters are considered. It is typically different from the previous investigation on the control policy with time-invariant gain parameters. The exceedance probability of structural states and control force serves as the critical argument of probabilistic criterion, whereby the parameter optimization of control policy can be readily achieved. A randomly base-excited shear frame structure with Bouc-Wen behaviors is used as the objective for control test. Numerical result indicates the efficiency of the proposed stochastic optimal control schemes that the variation of inter-storey drift of the structure reduces significantly, and the structural safety is enhanced sufficiently. The benefit of optimal polynomial control with time-invariant gain parameters limits in system stability hinging on the control force; while the optimal control with time-variant gain parameters involves the contribution of structural velocity and displacement to the gain matrix at each time step, which results in a better structural performance with a lower control effort.
彭勇波,李 杰 . 非线性时变结构随机地震响应最优多项式控制[J]. 振动与冲击, 2016, 35(1): 210-215.
PENG Yongbo, LI Jie. Optimal polynomial control of random seismic response of non-linear time-varying structures. JOURNAL OF VIBRATION AND SHOCK, 2016, 35(1): 210-215.
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