桥梁现状动态识别的试验研究

EXPERIMENTAL STUDY ON DYNAMIC IDENTIFICATION OF EXISTING BRIDGES

本文引用系统识别概念,提出了以实测频率为基础识别桥梁各单元刚度的理论和方法,可用于识别桥梁各部位的损伤程度,并计算相应的内力重分布。在动态识别试验研究过程中,本文揭示了梁高阶振动时的若干特性,提出了新颖的带短刚臂梁的振动模型,并用广义物理参数列向量迭代法,识别了试验梁在逐步破坏过程中各单元的刚度分布。经与实测结果比较,识别结果是令人满意的。

On the concept of system identification, a new inverse iterative procedure of dynamics is presented in this paper to identify the stiffnesses in all parts of the structure based on measured natural frequencies. The result can be used to calculate corresponding stress redistribution, as well as to detect the deterioration throughout the bridge. In the experimental study of system identification, some interesting behaviors have been founded when higher modes of vibrations occurred on the girder. An improved vibration model of girder, having short rigid arms, is there by estabilished. The distributions of stiffnesses in all parts of the twelve test girders in successive deteriorating periods are quantified with the iterative procedure of column vector of generalized physical parameters. The identification results are satisfactory as compared with the experimental test data.