巨-子结构控制体系的参数优化及随机响应灵敏度分析

摘要

In order to study the optimal parameters of the isolation layer in mega-sub control system, equation of motion of mega-sub control system was established, and the parameter optimization of mega-sub control system was studied based on the genetic algorithm theory where base shear was used as the optimization object function. The sensitivity of the stochastic response of the mega-sub control system to the structure' s parameters was analyzed by virtual excitation method and perturbation method. From the sensitivity of variance of the main structure story drift, isolation layer story drift, and the absolute acceleration variance of the top substructure to each parameter. It shows that the sensitivity of the response of the structure is weaker to the stiffness of substructure, and is more sensitive to the quality of substructure. The stiffness and damping of isolation layers,which also explains the reasons why that the mass ratio, frequency ratio and damping ratio are usually used for performance analysis of mega-sub control system.%为了研究巨-子结构控制体系中隔震层的最优参数，建立了巨-子结构控制体系的动力微分方程，基于遗传算法理论以基底剪力最小为优化目标对结构的物理参数进行了优化。采用虚拟激励法和摄动法，分析了巨-子结构控制体系平稳随机响应对各参数的灵敏程度。通过主结构层间位移方差、隔震层层间位移方差、子结构顶层绝对加速度方差对各参数的敏感程度分析表明，各响应对子结构的层刚度敏感性最小，而对子结构层质量、隔震层层刚度以及隔震层阻尼较为敏感。