基于回传射线矩阵法和Hilbert-Huang变换简支梁损伤检测

Damage Detection of Simple Beam Based on the Reverberation-ray Matrix Method and Hilbert-Huang Transform

基于回传射线矩阵法和Hilbert-Huang变换,研究了有损伤简支梁桥在方波脉冲荷载作用下速度波的时域、频域和时频响应,桥梁结构的局部损伤用减小横截面面积来模拟.结果表明:在时域里纵波可以判定简支梁桥存在损伤及损伤位置和损伤区域,横波只能判定结构有损伤存在;在频域里,纵波的振幅谱、功率谱只能判定简支梁桥存在损伤,相位谱不能用于结构检测;在时域-频域里,纵波可以清晰、直观的确定简支梁桥存在损伤、损伤位置及损伤区域,对结构的损伤诊断有较好的适用性.

Based on the reverberation-ray matrix method and Hilbert-Huang transform,the paper studied time domain,frequency domain and time-frequency response of velocity wave when the damaged simple beam bridge was under the pulse load of square waves.The partial damage of simple beam bridge was modeled by reducing the cross-sectional area.Results show that,in time domain,the axial velocity wave helps to determine whether damages have been caused to a simple beam bridge,and to discover the location of damages and the damaged areas,while transverse velocity wave can only help to determine if damages happen to the bridge structure.Results also show that,in frequency domain,the amplitude spectrum and power spectrum of axial velocity wave can only help to judge if damages exist in simple beam bridges,and phase spectrum can not be used for structure detection.The axial velocity wave in the time-frequency domain helps to clearly and intuitively detect damages of a simple beam bridge and helps to determine the location of the damages and the damaged areas,and is significantly applicable for the detection of structure damages.