激光超声技术在先进复合材料无损检测中的应用研究

为实现航空航天先进复合材料的非接触、高精度检测，研究激光超声技术在复合材料无损检测中的应用。制备预埋人工缺陷的碳纤维树脂基复合材料和陶瓷基复合材料试样，利用自主研制的激光激励、激光探测的全光学激光超声无损检测系统进行试验研究，实现碳纤维复合材料层压结构模拟分层缺陷检测，层压复合材料紧固孔边沿分层检测，以及陶瓷基复合材料分层检测。研究结果表明:激光超声检测技术可以有效检出碳纤维树脂基复合材料内部直径2 mm以上分层型缺陷，可检出碳纤维复合材料紧固孔边沿的小尺寸分层，可表征C/SiC复合材料内部直径5 mm以上分层，在航空航天工程领域应用前景广阔。

Application of Laser Ultrasonic Technology for Nondestructive Testing of Aerospace Composites

In order to realize the noncontact and high precision testing of aerospace composites, the application research for the testing of composite materials with laser ultrasonic technology is carried out. Various kinds of composite materials with simulated defects are prepared as specimen, including the carbon fiber reinforced composites and ceramic matrix composites. An all optical laser ultrasonic testing system with laser generation and detection is self-developed and the corresponding experiments are conducted based on the system. The nondestructive testing of the composite specimens with simulated defects are realized, including the detection of delamination in carbon fiber reinforced composites, the detection of drilling-induced delamination in carbon fiber reinforced composites, and the detection of internal delamination in C/SiC composites. The results prove that the laser ultrasonic testing technology is applicable for the testing of internal delamination with a diameter larger than 2 mm in carbon fiber reinforced composites, the pony-size drilling-induced delamination can be detected, and the internal delamination with a diameter larger than 5 mm in ceramic matrix composites can be characterized. It has a wide range of applications in aerospace industry.