碳纤维复合材料超声脉冲反射信号频域建模

对碳纤维复合材料(CFRP)层板超声脉冲反射信号频域进行研究,首先分析了CFRP层板中纤维层和树脂层的声波反射系数频域特征,结果表明,正常纤维层和树脂层、含孔隙纤维层和厚树脂层对反射系数有不同的影响。在此基础上建立了CFRP层板超声脉冲反射信号频域模型,反射信号频谱由正常纤维/树脂层频响、含孔隙纤维层频响、厚树脂层频响、探头频响以及噪声信号频响组成。使用该模型对含孔隙和无孔隙CFRP层板分别进行数值模拟,得到的频谱和对应CFRP层板实验信号频谱相比,两者主要频率成分具有一致性。

Ultrasonic Pulse-echo Model for Carbon Fiber Reinforced Polymer in Frequency Domain

The frequency domain of ultrasonic pulse echo signal obtained from carbon fiber reinforced polymer (CFRP) was studied. First the frequency domain feature of reflection coefficient for the fiber layer and resin layer in CFRP laminate was analyzed. The result shows that normal and porous fiber layer, and normal and thick had different influence on the acoustic reflection coefficient. Based on the result above, the frequency domain model for the pulse echo signal acquired from CFRP laminate was established. The pulse echo signal spectrum was composed of normal fiber/resin layer response, porous fiber layer response, thick resin layer response, probe response and noise signal response. Then the numerical simulation of CFRP laminate was implemented based on the model. The simulation signal spectrum of CFRP laminate with voids as well as the spectrum of CFRP laminate without voids was obtained. The results show that the simulation signal spectrums had the same main frequency components with the corresponding experimental signal spectrums.