MULTI-CORE COMPOSITE LAMINATES

Laminates containing multiple core layers and additional reinforcing s heets, differing from traditional sandwich construction which contains one thick core layer and two outer skins, are constructed and tested. These constructions are compared with similar traditional sandwich co nstructions with an emphasis on impact behavior. Nondestructive evalua tion of impacted panels quantitatively displays the relative damage be tween the two constructions. Although the multicore construction does possess less flexure strength, residual compression strength test resu lts show that the multi-core construction possesses greater strength t han the traditional sandwich laminate. Ballistic limits are determined for some multicore laminates, and a simple static punch energy method is shown to provide good predictions of these limits.