CFRTP-聚氨酯夹芯板内部缺陷的Lamb波检测方法研究

Study on Lamb Wave Testing Method for Internal Defects of CFRTP-Polyurethane Sandwich Panels

针对碳纤维增强热塑性复合材料(CFRTP)-聚氨酯夹芯板在发泡过程中产生的气孔缺陷问题,利用Lamb波对这一界面缺陷实施检测。采用COMSOL软件建立了基于压电效应的聚氨酯夹芯板多物理场耦合检测模型,以掌握Lamb波的激发特性,并确定了垂直入射方式有利于产生非对称型Lamb波。通过仿真计算与试验验证相结合的方式,证明了聚氨酯夹芯板内部缺陷会引起Lamb波接收信号幅值和传播时间发生变化,以幅值变化较为明显。结果表明:当间距固定时,信号幅值与缺陷面积呈正相关变化,缺陷深度对其影响较小。

The porosity defect of carbon fiber reinforced thermoplastic composite(CFRTP)-polyurethane sandwich plate during the foaming process was detected by Lamb wave.The multi-physical field coupling detection model of polyurethane sandwich panel based on piezoelectric effect was established by using COMSOL software to grasp the excitation characteristics of Lamb wave,and it was determined that the vertical incident mode was beneficial to the generation of asymmetric Lamb wave.Through the combination of simulation calculation and experimental verification,it was proved that the internal defects of polyurethane sandwich panel can cause the amplitude and propagation time of Lamb wave to change,especially the amplitude change was more obvious.The results show that when the spacing is fixed,the signal amplitude is positively correlated with the defect area,and the defect depth has little effect on it.