带表面裂纹连续梁损伤识别的曲率模态小波分析  

Surface crack identification of continuous beam using wavelet analysis of curvature mode

作　　者：管德清[1] 潘伟[2] 

机构地区：[1]长沙理工大学土木与建筑学院 [2]山东英才学院建筑工程学院

出　　处：《交通科学与工程》2009年第3期35-39,共5页Journal of Transport Science and Engineering

基　　金：国家自然科学基金资助项目(50578018);湖南省优秀博士论文基金资助项目

摘　　要：以带横向非对称非贯通表面裂纹的连续梁为研究对象,利用小波奇异性检测原理,提出了带表面裂纹连续梁损伤识别小波分析方法.以带表面裂纹连续梁三维有限元分析求解梁的位移模态为基础,利用中心差分法得到梁的曲率模态,再用sym4小波对曲率模态进行连续小波变换,根据小波系数模极大值识别损伤位置,以一个三跨连续梁内两处半椭圆形表面裂纹的损伤识别为例,通过数值计算分析,验证了方法的有效性.同时,计算结果表明,运用曲率模态小波变换识别连续梁损伤比基本振型的小波变换方法更为准确、有效.该研究对带表面裂纹结构的损伤诊断应用具有参考价值.A method for surface crack identification in continuous beam is proposed. It is based on wavelet singularity detection and focused on transverse unsymmetrical and nonpenetrative surface crack. Solving curvature modal parameters of continuous beam with cracks by means of the three-dimensional finite element theory, using the central difference method to obtain the curvature mode of continuous beam, and applying the sym4 continuous wavelet transform （CWT） to analyse the curvature mode, then the crack location of the continuous beam could be identified by the maximum of wavelet coefficients. The validity of the method has been proved by the analysis of a three span continuous beam which has two semielliptic surface cracks. C6mpared with the result of the modal analysis, it can be concluded that the method using wavelet analysis of curvature mode is more accurate and more effective. The method may be use- ful in surface crack identification and diagnosis in structures.

关 键 词：表面裂纹 损伤识别 曲率模态 连续小波变换 

分 类 号：TU317.5[建筑科学—结构工程] TN911.6[电子电信—通信与信息系统]