Low-velocity impact of functional gradient honeycomb sandwich plate with CFRP face sheets

The impact process and resistance capability of honeycomb plate with carbon fiber reinforced polymer (CFRP) face sheets were studied by using finite element model (FEM), and the FEM was verified by comparing with impact experiment. The density gradient was introduced into the traditional honeycomb structure by changing the wall thickness and the protection characteristics of functional gradient (FG) honeycomb sandwich plate under low-velocity impact (LVI) were simulated under different impact energies and gradient coefficients α. The energy absorption characteristics of the FG and the traditional sandwich plate were compared through FEM. The results show that, under low impact energy, the honeycomb sandwich plate with α>1 has better energy absorption. With the increase of impact energy, the core with absorbing energy advantages changes gradually from α>1 to α<1, when the whole sandwich plate is penetrated, the sandwich plate with α<1 has better energy absorption characteristics. Under the impact energy of 20 J, 50 J and 100 J, the energy absorptions of functional gradient sandwich plates are 7.54%, 5.33% and 8.65% higher than that of traditional sandwich plates with the same mass.