【摘要】 近断层地震作用可能使被动控制的基础隔震系统产生过大的加速度反应。为克服被动控制隔震系统这一局限性,针对含有可变摩擦阻尼器的基础隔震系统,提出了一种基于对场地加速度信号短时傅里叶变换的控制算法,预估隔震的失效,即时改变隔震层的摩擦阻尼。在三种不同类型的地震波作用下,对一个含有叠层橡胶支座和可变摩擦阻尼器的多自由度层模型使用Simulink进行时程分析。分析表明,该算法控制下的半主动隔震系统能够有效改变被动控制隔震系统对近断层地震的放大效应,限制隔震层的位移。更多还原

【Abstract】 Conventional isolation systems may induce an excessive response in near-fault earthquakes.A new short time Fourier transformation(STFT) control algorithm for Variable Friction Dampers(VFD) was developed to improve the performance of base isolation buildings in near-fault earthquakes.The STFT controller varied the clamping force in the VFD damper to achieve the response reduction.In addition,the STFT algorithm was implemented analytically on a Multi Degree of Freedom System(MDOF) with laminated rubber bearings and variable friction dampers in Simulink environment.Three types of earthquakes representing a wide variety of ground motions were considered as the ground excitations in the simulation.The numerical results showed that,compared with conventional isolation systems,the semi-active isolation system controlled by the STFT algorithm can reduce the excessive response in near-fault earthquakes effectively.更多还原