Deformation and Fracture of CFRP under Hyper-Velocity Impact Test Using Laser-Accelerated Flyer.

Using laser-accelerated Al flyers, we examined hyper-velocity impact tests of CFRP (carbon fiber reinforced plastics) laminates as a simulation of orbital debris impact. A short-pulsed intense laser beam can accelerate a small flyer as fast as LEO (low earth orbit) satellite velocity. We succeeded in observing the deformation and fracture processes of the CFRP targets with a high-speed framing camera. When the pulsed laser was set the single shot energy of 26.4 J, corresponding to Al flyer velocity 8.3 km/s, we observed that the fiber breakage at the back surface of the CFRP target occurred at about 500 ns after the impact. After the impact experiments, we investigated damages of the CFRP target with an optical microscope and a scanning electron microscope (SEM). The damage to the back surface of the target varied with the laser energy. In the case that the laser energy was 19.5 J, cracks along carbon fibers were found. When the laser energy was 26.4 J, interlaminar delaminations as well as cracks along carbon fibers were observed.