先进树脂基复合材料纤维褶皱缺陷阵列超声全聚焦成像

Array ultrasonic total-focus imaging for advanced resin matrix composite fiber wrinkle defect arrays

先进树脂基复合材料因其密度低、强度高等特点,广泛应用于航空航天领域。纤维褶皱是先进树脂基复合材料制造过程中产生的一种缺陷,常规超声检测效率低,而阵列超声全聚焦成像检测技术则依赖准确的声传播延时。针对先进树脂基复合材料中的各向异性和多层折射界面而导致声波延时计算困难的问题,提出了一种使用Viterbi搜索算法的声线示踪方法,用于计算阵列超声全聚焦成像检测的时间延迟。对5.92 mm厚的多向碳纤维复合材料层压板进行阵列超声全聚焦成像检测实验,结果表明,使用声线示踪法计算延时,可以使采集的全矩阵信号被准确地相干叠加,有效检测出多向碳纤维复合材料层压板中的纤维褶皱缺陷。

Advanced resin matrix composites were widely used in aerospace applications because of light weight and high strength. Fiber wrinkle defects were one of the defects in advanced resin matrix composites, which were inefficiently detected by conventional ultrasonic inspection, while the array ultrasound total-focus imaging detection technique relies on accurate acoustic propagation delay. To address the problem of difficult acoustic delay calculation due to anisotropy and multilayer refractive interfaces in advanced resin matrix composites, ray tracing method based on the Viterbi search algorithm was proposed for calculating the time delay of array ultrasonic total focus imaging inspection. The results of the array ultrasonic full-focus imaging inspection experiments on 5.92 mm thick multidirectional carbon fiber composite laminates show that the use of the ray tracing method to calculate the delay time allows the collected full-matrix signals to be accurately and coherently superimposed, effectively detecting the fiber winkle defects in multidirectional carbon fiber composite laminates.