摘 要:通过钢梁损伤试验,验证基于小波包能量谱的结构损伤预警方法在实际结构上应用的有效性。对钢梁进行完好工况和三个损伤工况的动力响应测试,对得到的响应进行小波包分解,考察损伤前后各个特征频带的能量变化。试验结果显示,损伤预警指标ERV和ERVD能够对三种损伤工况做出有效预警;同一工况的多次测试得到的损伤预警指标ERVD虽有变化但变化不大。基于小波包能量谱的结构损伤预警指标对结构损伤具有敏感性、对测试噪声具有鲁棒性,可以用于实际结构损伤预警。
Abstract:Through a steel beam damage experiment, the validity of the structural damage alarming method based wavelet packet energy spectrum is proved. This experiment has four cases, one of which is the initial case and others are three damage cases. Dynamic responses of a steel beam are measured and decomposed by wavelet packet and energy varieties of characteristic frequency bands are investigated. Experimental results reveal that three damage cases can be alarmed by the damage alarming indices ERV and ERVD and that ERVD varies slightly along with different measurements of the same damage case. The structural damage alarming indices based on wavelet packet energy spectrum are sensitive to damages, robust to noise and can be applied to actual structures.