基于模态应变能和小波变换的结构损伤识别研究

针对单一方法对结构同时发生多处不同程度损伤识别的不敏感性缺陷，本文结合小波变换在时域、频域内表征信号局部特性且能够聚焦到信号或函数的任意细节进行处理的能力，提出了一种基于单元模态应变能和小波变换的结构损伤识别方法。在单元模态应变能基础上，利用小波变换系数的变化和分布情况构建单元模态应变能小波变换结构损伤指标，通过对简支梁的数值模拟和斜拉桥模型试验研究的结果与单元模态应变能平均变化率作为损伤识别指标的计算结果进行对比，结果表明该方法能有效确定结构同时发生多处不同程度损伤的位置和估计损伤程度，为实际工程应用奠定了基础。

Structural damage identification based on modal strain energy and wavelet transformation

Single identification method is not sensitive to structural multiple different level damages.An approach of structural damage identification based on modal strain energy and wavelet transformation with the ability to denote local features of a signal in time domain or frequency domain and to process any details of a signal or a function was proposed.The structural damage index was built with the change and distribution of wavelet transformation coefficients based on elemental modal strain energy.Through numerical simulation of a simply supported beam and a cable-stayed bridge model experiment study,compared with the elemental modal strain energy method,the proposed method could effectively determine multiple different level damage locations in a structure and estimate damage levels.The results laid a foundation for the practical engineering applications of the proposed method.