基于小波分析的简支梁桥损伤识别

提出了基于小波子带信号能量曲率变化的损伤识别方法。分别对完好和损伤状态下结构的振动响应进行二进离散小波变换,通过信号子带分解与重构将响应分解到不同频带,使叠加的模态响应分离。定义了信号相对能量曲率差损伤指标,利用该指标对结构的损伤进行识别定位。应用此方法对一简支梁桥进行损伤数值分析,结果表明:二进离散小波变换可以对结构振动响应中叠加的多阶模态信息进行有效分离;信号相对能量曲率差指标可以对损伤进行有效识别,且不受激励位置及荷载大小影响。最后通过模型实验验证了该方法的正确性及可行性。

Damage Identification of Simply Supported Beam Bridges Based on Wavelet Analysis

An approach to structural damage identification based on the change of wavelet sub-band signal energy curvature is proposed. To analyze the vibration responses of the intact and damaged structures, the dyadic discrete wavelet transform is adopted. The signal is then decomposed into different sub-bands at the same time the different modal responses are separated. The damage index of the relative energy curvature difference is defined and used to identify the damage location. The numerical simulation study of a simply supported beam bridge shows that the dyadic discrete wavelet transform can successfully separate the different modal responses into different bands, and the damage index can be used to effectively determine the location of the damage, which cannot be affected by the vibration position and the load size. Finally, the method is verified with the experiment of a simply supported beam bridge model.