碳纤维增强复合材料层合板Lamb波衰减特性研究

Attenuation characteristics of Lamb wave in carbon fiber reinforced composite laminated plate

为提取适用于碳纤维增强复合材料层合板声发射故障诊断的模态信号,利用三维弹性理论及传递矩阵法获得Lamb波的频散曲线。以碳纤维增强复合材料层合板为研究对象搭建实验平台,改变断铅激励位置从而获得不同声发射信号。对采集的声发射信号进行小波尺度谱分析,结合频散曲线分离出不同模式的Lamb波,分别研究其不同频率的幅度及能量衰减特性。实验结果表明,较其它信号,低频率S0波幅度信号衰减速度较低,对碳纤维增强复合材料层合板的声发射故障诊断研究具有较大优势。

In order to acquire the modal signal suitable for acoustic emission fault diagnosis on carbon fiber reinforced composite laminated plates, the 3D elastic theory and transfer matrix method were introduced to get Lamb wave dispersion curves. An experimental platform was setup to test the Lamb wave propagation property of carbon fiber reinforced composite laminated plate, and different acoustic emission signals were motivated by changing the location of pencil breakpoints. The wavelet scale spectrum and dispersion curves were used to separate different Lamb wave modes, and then the amplitude and energy attenuation characteristic were investigated respectively under different frequency. The experimental results show that, compared with other modal signals, the amplitude signal of SO mode with low frequency has great advantage in the aspect of acoustic emission fault diagnosis on carbon fiber reinforced composite laminated plates because of its slower attenuation speed.