Experimental Investigation on the Effects of Core/Facing Interface Performance on the Low-Velocity Impact Behavior of Honeycomb Sandwich Panels

This paper gives an important contribution by investigating the effectiveness of core/facing interface performance of aluminum honeycomb sandwich panels under low-velocity impact energy. Low-velocity drop tests were conducted on five different panels under 50, 75, and 100 J impact energies (loads). The following procedure is followed to evaluate the impact response of panels: the force-time histories are acquired; the numerical integration method is applied, and force-displacement histories are obtained; and then the damage mechanism and theoretical energy balance modeling are used to analyze the effectiveness of core/facing interface performance on the impact behavior of the panels. Scanning electron microscopy is used to examine the microstructural and the morphology of the core/face sheet interface of the aluminum honeycomb sandwich panels. The effects of voids, interface, and cohesive cracks on the impact behavior of the panels are analyzed. Energy balance modeling proved that energy absorbed in the bending and shear deflections increased as the resistance at the core/facing interface is increased. In addition, changing the initial impact energy from 50 to 100 J produced more than 120% increase in the effectiveness of the panels in terms of energy absorbed in shear and bending deformations.