基于转角模态小波分析的弹性地基梁损伤识别研究  

DAMAGE IDENTIFICATION OF ELASTIC FOUNDATION BEAMS BASED ON WAVELET TRANSFORM OF ROTATING ANGLE MODES

作　　者：管德清[1] 黄燕[1] 

机构地区：[1]长沙理工大学桥梁与结构工程学院,长沙410076

出　　处：《振动与冲击》2008年第5期44-47,共4页Journal of Vibration and Shock

基　　金：国家自然科学基金(50578018)

摘　　要：基于转角模态小波变换研究了带刚度下降段的弹性地基梁损伤识别问题,提出了采用文克尔地基力学模型,用等效刚度代替梁内损伤段的刚度,通过有限元计算求解损伤梁的转角模态参数,来识别梁内刚度下降段位置的方法。以两端简支弹性地基梁为例,分别考虑了梁单独损伤、弹簧单独损伤、梁和弹簧同时损伤且损伤位置不同的三种情况,通过建立带损伤段梁的有限元模型,用Lanczos法对结构的转角模态进行了计算分析;再应用mexh小波对其进行连续小波变换,通过小波系数模极大值点判断梁内刚度下降段的位置。数值算例验证了方法的有效性,研究对工程结构损伤诊断的应用具有参考价值。The wavelet finite element method based on transform of rotating angle modes was proposed for damage identification of beam segment with declined stiffness on elastic foundation. The location of declined stiffness segment of beam was identified by adopting a Winkler-type elastic foundation model, using equivalent stiffness to replace the stiffness of damaged beam segment, and solving modal parameters of damaged beam. Taking a simply-supported beam on elastic foundation as an example, based on wavelet finite element method the model of damaged beam was constructed, and Lanczos numerical method was used to modal analysis of structure and its rotating modes were calculated. Then the mexh (Mexican Hat) wavelet was used to transform it,and the location of the beam segment with declined stiffness was identified by examing the maximum wavelet coefficient. The numerical example indicates that the current method is effective and accurate, and the method may be useful in damage identification and diagnosis for structures.

关 键 词：弹性地基梁 损伤识别 转角模态 小波变换 有限元 

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]