DYNAMIC-RESPONSES OF COMPOSITE SANDWICH PLATE IMPACTED BY A RIGID BALL

A refined formulation of composite sandwich plate is employed to study the dynamic response of impacted sandwich plate. In this refined formulation, the faces of the sandwich plate are modeled as two separate Mindlin plates whereas the core is considered to have both transverse shear and normal stiffnesses. This model allows the including of relative deformations of two faces under concentrated load. The capability of modeling relative deformation of two faces is important since the impacted face behaves differently from the opposite one. Finite element method is used to discretize the sandwich plate based on this refined theory. Experimental works are conducted on the impact of [0(2)/90(2)/0(2)/FOAM]s sandwich plate with graphite/epoxy faces and FR10110 rigid foam core. Dynamic strain histories obtained from theoretical analysis and the strain-gage experimental results are compared in good agreement. It indicates that the theoretical model employed herein describes the dynamic behavior of composite sandwich plates due to low velocity impact. In addition, effects of impact velocity and mass of the impactor are investigated.