Experimental and numerical characterization of low-velocity impact damage of a CFRP laminate with interlayers

In this paper, the microscopic damage behavior of a carbon fiber reinforced plastic laminate with interlayers subjected to low-velocity impact was experimentally and numerically investigated. Impact tests were conducted by using a guided drop-weight test rig, whereas in numerical analysis, finite element (FE) software was employed to simulate low-velocity impact damage on the laminate. The base ply and the interlayer were modelled as an orthotropic elastic material and an isotropic elastic material, respectively. Cohesive elements were introduced not only between the base ply and the interlayer but also inside the base plies to simulate the interlaminar and intralaminar delaminations. From the experimental and numerical results, it is proved that the crack and the dent on the front surface of the laminate was due to compressive stress in the fiber (0°-) direction. Both interlaminar and intralaminar delaminations extend in the 0°- and transverse (90°-) directions. Especially, the both delaminations should be considered to reproduce the overall impact behavior including damage in the FE analysis.