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

我们研究了超高速冲击试验的CFRP（碳纤维增强塑料）层压板使用激光加速铝飞片。通过短脉冲强激光束的照射，铝飞片被加速到6〜 9 km/s。利用高速分幅相机成功地观测了CFRP靶板的变形和断裂过程。结果表明，CFRP从靶板的碰撞表面飞溅出来。靶后表面的变形速度约为100 ~ 700 m/s。在冲击实验后，我们用光学显微镜、扫描电子显微镜（SEM）和激光显微镜研究了CFRP靶的损伤。我们在飞片撞击的背面发现了I型断裂面。在后部观察到了II型损坏，在那里它稍微离开了弹着点。通过对靶板截面的观察，发现了多层层间脱层现象，并据此提出了CFRP层合板在超高速冲击载荷下的断裂模型.裂纹是由火花（模式I）2引发的。然后，裂纹在剪切力的作用下沿着碳纤维扩展（模式II）3。最后，在背面的纤维断裂的张力使用Dyna 3D的超高速碰撞进行了三维模拟。介绍了从实验中的分幅图像和CFRP靶的损伤观察推测的断裂机理。冲击变形与试验结果定性一致。

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.