高阻尼橡胶支座隔震桥梁简化力学模型动力分析

DYNAMIC ANALYSIS OF HDRB ISOLATED BRIDGES BASED ON SIMPLIFIED MECHANICAL MODEL

高阻尼橡胶支座作为隔震支座具备承载能力、恢复力和阻尼(吸收能量)三位一体的功能。以某一采用高阻尼橡胶支座进行隔震的规则连续梁桥为例,进行简化力学模型动力学分析。利用Opensees软件建立双质点简化力学模型,并与SAP2000有限元分析模型进行对比,研究简化力学模型的可行性与计算精度。结果表明:简化力学模型可以较为精确地计算出隔震桥梁的响应幅值;在相同地震波作用下,简化力学分析模型的分析结果基本能够满足工程精度要求并与有限元分析模型结果较为接近。

High damping rubber bearing( HDRB) as a kind of isolation bearing has the functions like bearing capacity,restoring force and damping( energy absorption). In this paper,a regular continuous girder bridge isolated with high damping rubber bearings was taken as a research object. A simplified Two Degrees of Freedom mechanical model was established in Opensees software,and compared with the FEM model established in SAP2000 to study the feasibility and accuracy of the simplified mechanical model. The results show that the response amplitude of the isolation bridge can be accurately calculated by the simplified mechanical model. Under the same seismic waves,the analysis results obtained from the simplified mechanical model meet the engineering accuracy and agree with the FEM model.