移动荷载作用下梁裂缝识别的小波方法研究  

IDENTIFICATION OF SIMPLE-SUPPORTED BEAM CRACKS BY MEANS OF WAVELET ANALYSIS

作　　者：任宜春[1] 马石城[1] 林琳[1] 

机构地区：[1]湘潭大学建筑工程系,湘潭411105

出　　处：《振动与冲击》2004年第2期82-85,51,共5页Journal of Vibration and Shock

基　　金：湖南省教育厅科学研究项目 (O3C468)资助

摘　　要：利用小波分析对简支梁的裂缝进行识别。通过对带裂缝简支梁在移动荷载作用下的跨中响应用Mexicanhat小波进行连续小波变换 ,从小波系数的模极大值点有效地得到荷载经过裂缝的时间 ,从而识别裂缝位置 ,从模极大值处的Lipschitz指数判断裂缝深度 ,Lipschitz指数随裂缝深度的增加而减小。同时讨论了荷载移动速度和裂缝位置对Lips chitz指数的影响。通过分析和仿真计算获得满意结果 ,在梁结构损伤诊断中具有较高的应用价值。A wavelet-based approach is proposed for crack identification in beam structure. The displacement at the midpoint of a cracked simple-supported beam under mobile force is analyzed with the continuous wavelet transform by using a Mexican hat fundamental wavelet. The time when the load moves through a crack is determined by the modulus maximum of wavelet coefficients. So the location of the crack can be detected. It is also addressed that the magnitude of the Lipschitz exponent can be used as an indicator of the damage extent. The Lipschitz exponent decreases with the increase of crack depth. The influences of the velocity of moving load and the crack location on the Lipschitz exponent are discussed. The validity of the proposed method is investigated by both analysis and simulation.

关 键 词：粱 小波分析 振动 移动荷载 Lipschitz指数 裂缝 

分 类 号：TU317.5[建筑科学—结构工程]