基于弹性导波的厚钢梁结构的损伤检测

弹性导波由于其对损伤的敏感性和长距离传播特性,成为近年来结构健康监测领域的一个研究热点.探讨了利用 PZT 换能器在较厚结构中进行基于弹性导波方法的损伤识别的可能性.首先参考 Lamb 波的频散曲线,设置了导波的激励信号参数如激励频率、激励波形周期数等;基于优化的激励波形和 PZT 换能器布局,在结构健康监测实验平台上对试件进行了检测.通过对实验结果的处理分析,计算出导波的群速度,并根据群速度和飞行时间(ToF)得到了损伤的位置信息.结果表明利用导波方法能够针对较厚结构进行损伤定位并能识别出不同大小的损伤.

Damage detection in thick steel beam based on elastic guided wave

Because of the good characteristics of long range propagation and high sensitivity to damage,elastic guided wave is being a hot spot in the structure health monitoring community. The possibility for damage detection in relatively thick structures with PZT transducers based on guided wave approach was discussed. The excitation wave parameters such as the center frequency and the wave cycles were studied based on the dispersion curves of Lamb waves. Based on the designed excitation waveform and the PZT layout,the diagnosis experiment was conducted. The guided wave group velocity was calculated according to the experiment result,and the location of damage was estimated with the group velocity and time of flight (ToF). The analytical result shows that with the approach the existence of damage can be detected and the damages with different depth in some thick structures can be identified.