基于小波变换的结构损伤诊断研究

Structure Damage Diagnosis Based Wavelet Transform

以对结构局部特征变化比较敏感的应变模态为基础,采用小波变换理论进行结构损伤定位及损伤程度的定量研究,通过小波变换的模极大值确定损伤位置,根据李氏指数表征奇异性大小的特性建立了与损伤程度之间关系。数值模拟表明,小波变换的损伤识别方法不需要损伤前结构的信息,通过模极大值及李氏指数进行损伤定位及定量识别结果精确可靠,为工程实践提供理论基础。

The Researches of structure damage location and extent identification were carried out by applying wavelet theory. Based on the strain mode which was sensitivity to structure local characteristics change, damage loeation was identified by modulus maximum of continuous wavelet transform. The relationship between Lipschitz exponent and damage extent was built according to the feature that Lipschitz exponent representing the order of the singularity. Numerical simulation showed the method of damage identification based wavelet transform could exactly detect the location and extent of the damage through modulus maximum and Lipschitz exponent, the message of undanmged structure was not needed in this method. The identification results indicated the proposed method was precision and facility which supplied the theory basis for engineering practices.