Evaluation of Energy Absorption and Damage for Sandwich Panels Subjected to Low Velocity Impact

抄録

Impact resistance and energy absorbing capability are of great interest in the design of sandwich structures. Thispaper experimentally studies damage, failure, and energy absorption properties of polyurethane (PUR) and polystyrene (PS)foam core sandwich panels with aluminum and glass fiber reinforced (GFR) composite face sheets subjected to low velocityimpact. Tests are performed using an Instron Ceast 9340 drop tower impact system at different impact velocities. Drop weighttests were conducted on sandwich panels with different types of foam and face sheet. Two commercial foams were used ascore for the sandwich panels: polyurethane Necuron 100 of 100 kg/m³ density and extruded polystyrene of 32 kg/m³ density.The experimental results were compared in terms of force-displacement response and damage status. It was found that theaddition of short glass fibers to the composite face sheets increased the maximum impact force and reduced the debonding ofthe bottom face sheets for both foam grades. The use of lower density polystyrene foam increased the flexibility of the panelsand improved the ultimate failure response of the composite sandwich panels. The energy absorbing capabilities of aluminumand composite face sheet sandwich panels with PUR and PS foam cores are evaluated by means of absorbed energy-timehistories and by specific parameters as normalized absorbed energy, specific energy absorption, and crush force efficiency.Stiffer panels behave better at lower impact velocities, while more ductile ones perform better if impact energy is increased.