本文以一座145m+2×260m+145m的大跨度连续刚构桥为背景,首先介绍了传感器优化配置算法、评估准则和安放位置的选择方法;其次,建立了该连续刚构桥的三维有限元模型,进行了环境振动试验,得到了桥梁的基本动力特性;再次,基于MAC矩阵和Fisher信息阵标准为理论基础的传感器优化布点算法,对桥梁健康监测加速度传感器布点方案进行了研究;最后结合该桥的实际情况,提出了加速度传感器优化布置方案。实时健康监测表明:基于本文的传感器布置方法实时监测能够获得该桥梁前10阶振型,可满足桥梁长期监测的需要。
In this paper, a long-span continuous rigid frame bridge with span arrangement of 145 +2×260 + 145m was selected as an engineering background. Firstly, the selection methods of acceleration sensor position were briefly introduced, considering the optimal placement algorithm and the evaluation criterion, and secondly, a threedimensional finite element (FE) model of the bridge was constructed, and the field ambient vibration testing was conducted, then, the dynamic characteristics of the bridge were extracted from the FE analysis and the testing. Thirdly, the optimal placement scheme of acceleration sensors for the bridge health monitoring was studied, on the basis of the MAC matrix and standard of Fisher' s information matrix. Finally, the optimal placement scheme of acceleration sensors was presented according to the real damage condition of the bridge. The real time monitoring resuits indicate that the first 10 orders of vibration frequencise and modal shapes can be extracted and the scheme can meet the needs of the bridge' s long-term health monitoring.