Experimental study on impact and flexural behaviors of CFRP/aluminum-honeycomb sandwich panel

To investigate the impact and flexure behavior of carbon fiber reinforced polymers/aluminum-honeycomb sandwich panel, low-velocity impact, compression-after-impact (CAI), and three-point flexure tests are conducted carefully. Four kinds of carbon fiber prepregs are selected to make face sheets by hot press preparation. Further, the digital image correlation technique is employed to record the damage evolution under the compression and flexure loads. The results show that the sandwich structure has two stages of impact response, first, the brittle behavior of the upper panel, and then the resistance of both sandwich and lower panel to absorb energy. In the CAI test, the failure position shifts from the ends to the impact cross section, and the compressive strength can be reduced by 40% only by 1 J impact. The strength of in-plane flexure is at least twice greater than that of out-of-plane flexure. The damage and deformation of in-plane flexure are found mainly in the upper panel and sandwich core, and the lower panel bends significantly.