基于MRD与LRB混合控制的隔震连续梁桥地震响应
Seismic Responses of Isolated Continuous Girder Bridges Based on Hybrid Control of MRD and LRB
-
摘要: 为了研究磁流变阻尼器(MRD)与铅芯橡胶支座(LRB)混合控制对桥梁结构地震响应及隔震效果的影响,以典型三跨连续梁桥为背景,采用平行板模型模拟MRD的本构关系,采用Bouc-Wen模型模拟LRB的力-位移非线性行为,通过对结构的离散建立无控制、LRB单独控制、MRD与LRB混合控制的多种控制工况有限元计算模型,运用有限单元方法建立系统的动力特性矩阵,并采用瞬时最优控制算法对其进行了非线性时程对比分析.分析结果表明:采用MRD与LRB混合控制工况与LRB单独控制工况相比,前者的结构地震响应明显降低,隔震效果得到明显提高;在桥墩、桥台处均安装MRD与仅在桥墩或桥台处安装MRD的LRB隔震桥梁相比,前者对结构地震响应的控制效果更好.Abstract: To investigate the seismic response and isolated effect of bridges influenced by hybrid control of MRD(magneto rheological damper) and LRB(lead rubber bearing),in the background of three spans isolated continuous girder bridges,parallel-plate model was adopted to simulate the constitutive relation for MRD,Bouc-Wen restoring force model was adopted to simulate the nonlinear hysteric characteristics for LRB,various control condition finite element analytic model considering no control,separate control of LRB and hybrid control of MRD and LRB were established by making the structure discrete,and system property matrix was obtained by using the FEM,using the IOC and combining various control condition to make the contrast analysis.The consequences indicate that hybrid control of MRD and LRB is significantly lower on the seismic responses than separate control of LRB,and isolated effect in hybrid control of MRD and LRB get obvious improvement compared with separate control of LRB;The control effect of LRB isolated bridges structure seismic responses of the MRD is installed at the piers and abutments are much better than those of the MRD installed at the piers or abutments.