基于转角模态小波变换的平面框架裂缝识别研究

Crack identification of plane frames based on wavelet transform of angle displacement mode

以有限元分析含裂缝平面框架的模态参数为基础,建立了基于转角模态小波变换识别平面框架裂缝的方法.利用Mexh小波对框架的转角模态进行小波变换,通过小波系数模极大值点来识别裂缝的位置.以一层平面框架为例,分别建立了框架梁含有裂缝、框架柱含有裂缝、框架梁和柱均含有裂缝的有限元模型,并通过转角模态小波变换来识别平面框架裂缝的位置.数值计算验证了方法的有效性.通过对平面框架基本振型和转角模态小波变换识别裂缝的比较发现,转角模态小波变换方法识别框架结构裂缝更为准确、有效.

By means of the wavelet analysis theory the damage identification of plane frame was studied. Based on the finite element analysis of model parameters, the method using the wavelet analysis of rotation mode was proposed for plane frames crack identification, and the Mexh wavelet transform was applied to analyze the rotation mode of plane frame, so the location of crack of the plane frame can be identified by the maximum of wavelet coefficients. Taking one-story plane frame for example, three finite element models, including a frame beam with a crack, each frame column with a crack, and each frame beam and column with a crack, were separately set up, and the above-mentioned method was applied to identify the location of the crack, and the results validate this method. Finally, compared with the result of the wavelet transform to analyze vibration mode and rotation mode, it can be concluded that the method using the wavelet analysis of rotation mode is more convenient and more effective.