Impact and compression-after-impact behavior of sandwich panel comprised of foam core and wire nets/glass fiber reinforced epoxy hybrid facesheets

In this paper, we manufactured a novel sandwich panel that comprised of the foam core and the hybrid facesheets by vacuum-assisted resin infusion process. In the hybrid facesheets, the reinforcing phases are made of woven glass fabric cloth in company with wire nets, while the matrix is epoxy resin. Four categories of specimens with different wire nets contents are designed. To investigate the impact resistance ability of the designed sandwich panel, low-velocity impact tests are performed with respect to the contact load, absorbed energy, and failure mode. Compression-after-impact test is conducted to determine the residual mechanical properties of the postimpact sandwich panels. Digital image correlation technology is adopted to measure the strain distribution in the panels in compression-after-impact test. Results show that wire nets in the facesheet of the sandwich panel could enhance the energy absorb ability as well as the compression-after-impact strength significantly. Fiber/wire nets breaking, delamination, and foam core cracking are the main damage modes formed in the impact event, while the incident energy is mainly absorbed by wire nets breaking. In compression-after-impact test, bucking and delamination are the main damage modes, and the compressive stability is enhanced by the wire nets.