基于频率及振型参数的结构损伤识别方法

Structural Damage Detection Method Based on Natural Frequency and Mode Shape

本文对基于结构模态参数的损伤识别方法进行了深入探讨,对一种传统的基于频率变化的结构损伤识别方法进行了分析改进,并建立了一种新的基于频率和振型参数的结构损伤识别方法。通过数值仿真证明传统的基于频率变化的结构损伤识别方法的单步识别精度随单元刚度损伤程度的增加而降低,提出此类方法宜设计成迭代算法,数值仿真结果表明本文的修正建议是合理有效的。针对有损结构前几阶固有频率和对应的模态位移可供利用的情况,提出一种基于广义逆的损伤识别方法,数值仿真结果证明了该方法的有效性。

A traditional damage detection method based on changes of natural frequencies was modified and updated, and a new damage detection method based on natural frequencies and mode shapes was proposed. The result of numerical simulation shows that the precision of the traditional damage detection method based on changes of natural frequencies becomes poor while the damage extent of an element is getting higher, therefore a modification of iterative algorithm was suggested. For the situation that some natural frequencies and corresponding mode shapes of the damaged structure could be obtained, a new damage detection method using pseudo-inverse was presented. The results of the simulation show the high efficiency of the proposed algorithm and the pseudo-inverse method.