基于声发射技术的 T800 碳纤维复合材料拉伸失效机制分析

To reveal the failure mechanism of the carbon fiber wound composite case in solid rocket motors under multiple load conditions‚ tensile tests were carried out on unidirectional T800 carbon fiber reinforced plastic specimens under different off-axis angles. By employing acoustic emission(AE) non-destructive testing technology‚ complete waveform signals of the specimens were acquired‚ and characteristic parameters of AE signals were selected using the Pearson correlation coefficient. The K-means clustering algorithm was used to cluster AE signals‚ and the different damage mechanisms were corresponding to the AE cluster based on the microscopic fracture morphology captured by scanning electron microscopy(SEM). Furthermore‚ representative volume elements in conjunction with a progressive damage method was utilized to realize the numerical simulation of damage process of unidirectional composites. The analysis results show that the correlation coefficient between the peak frequency and amplitude of the AE signal is less than 0.2. By combining with the stress-strain curve obtained from numerical simulation‚ cluster analysis is conducted on the AE signal using the two parameters‚ which indicate that fiber breakage has the highest peak frequency‚ matrix cracking has an intermediate peak frequency‚ interface debonding has the lowest peak frequency and the AE signal amplitude is highest when macroscopic damage occurr in the test specimen.