线性阻尼隔震与非线性隔震系统近断层地震反应分析  

Seismic response analysis of linear damping and nonlinear base-isolated systems under near-fault ground motion

作　　者：龚微[1] 熊世树[1,2] 

机构地区：[1]华中科技大学土木工程与力学学院,武汉430074 [2]华中科技大学控制结构湖北省重点实验室,武汉430074

出　　处：《振动与冲击》2016年第24期108-114,共7页Journal of Vibration and Shock

摘　　要：为了研究近断层地震动作用对不同类型隔震系统地震反应的影响规律,对比分析了线性阻尼隔震与非线性隔震系统在不同脉冲周期近断层地震动作用下的地震反应,并提出了近断层地震动作用下隔震系统的改进方案.首先,采用三角函数衰减模型模拟分析近断层地震动作用的速度脉冲特性,根据其脉冲周期分布情况和结构基本周期选取了三条代表性近断层地震波。然后,考虑上部结构非线性,对线性阻尼隔震、非线性隔震和联合隔震的八层钢框架结构进行了地震反应时程分析。结果表明,较非线性隔震,线性阻尼隔震且阻尼比为0.2-0.3时能够满足大震时控制隔震层位移、小震时控制上部结构反应的理想隔震目标,且对不同脉冲周期具有适应性。脉冲周期接近或大于结构共振周期时,改进的联合隔震能进一步提高隔震效果和隔震安全性。To study the effect of the near fault ground motions on the seismic response of various types of isolation systems,the seismic responses of linear damping and nonlinear base-isolated systems under near fault ground motions with different pulse periods were compared. An improved near fault isolation system was proposed. First,the pulse behavior of near fault ground motions was simulated by a trigonometric function with attenuation. Three near fault ground motion records were selected based on the pulse period of ground motions and the fundamental period of structures. Then,timehistory analysis of an eight-story steel frame structure with the linear damping base isolation control at different damping ratios,the nonlinear base isolation control,and the combined isolation control were conducted with the consideration of the nonlinear behavior in the superstructure. It is shown that compared with the nonlinear base-isolated system,the linear damping base-isolated system with damping ratio of 0. 2- 0. 3 better satisfies the requirement of the ideal isolation objective,which aims at reducing the isolation displacement under extreme earthquake and reducing the response of superstructure under minor earthquake. This conclusion is suitable for different pulse periods. In addition,the combined isolation control can further improve the isolation effectiveness and isolation safety when the pulse period is close to or larger than the fundamental period of the structure.

关 键 词：隔震 近断层地震动作用 黏滞阻尼 滞回阻尼 脉冲模型 

分 类 号：TU352.1[建筑科学—结构工程]