レーザ誘起衝撃波を用いた航空宇宙材料の衝撃破壊に関する研究

我们使用激光加速Al飞片对CFRP（碳纤维增强塑料）层压板进行了超高速冲击试验。利用短脉冲强激光束辐照，使铝飞靶加速到6 ~ 9km/s。利用高速分幅相机成功地观察了CFRP靶材的变形和断裂过程。结果发现，碳纤维布从目标的碰撞表面溅射出来。靶体背面的变形速度约为100 ~ 700m/s。在撞击实验结束后，采用光学显微镜、扫描电镜和激光显微镜对CFRP靶材的损伤进行了研究。我们在飞片撞击的背面发现了I型断裂面。II型损伤出现在后部，在撞击点有一点脱落。通过对靶材截面的观察，发现了多层层间分层。基于以上结果，提出了CFRP复合材料在超高速冲击载荷作用下的断裂模型：裂缝是由剥落引起的（模式1）2。然后，裂纹通过剪切力（模式II）沿碳纤维扩展。最后，利用Dyna3D软件进行了超高速冲击的三维模拟。介绍了从实验分幅图像中推测的断裂机制和CFRP靶材的损伤观察。含剥落的冲击变形与实验结果定性一致。

We examined hyper-velocity impact tests of CFRP (carbon fiber reinforced plastics) laminates using laser-accelerated Al flyers. Al flyers were accelerated to 6〜9km/s by irradiation of a short-pulsed intense laser beam. We succeeded in observing the deformation and fracture processes of the CFRP targets with a high-speed framing camera. It was found that the CFRP was splashed out from the collision surface of the targets. The deformation velocity of the back surface of the targets was about 100〜700m/s.After the impact experiments, we investigated damages of the CFRP target with a optical microscope, a scanning electron microscope (SEM) and a laser microscope. We found fracture surfaces of mode I type exactly on the back of the flyer impact. Damages of mode II type were observed in the back where it came off the impact point a little. Multi-interlaminar delaminations were discovered by observation of the section of the targets.The following fracture model of CFRP laminates under hyper-velocity impact loading is proposed as these results.1. A crack is initiated by spallation (Mode I)2. Then, the crack is propagated along carbon fibers by shear force (Mode II)3. Finally, fibers at the back surface were broken by tensionThree-dimensional simulations of the hyper-velocity impact were performed using the Dyna3D. We introduced the fracture mechanisms presumed from the framing images at the experiments and the damage observation of the CFRP targets. Impact deformations with spallation agreed with the experiment results qualitatively.