Numerical Assessment of Impact Behavior of Composite Laminates with Variable Interply Delamination Strength

Abstract

The reasons of increasing use of composite laminates in modern aircrafts, vehicles and other applications are related to their high specific strength and modulus, together with their flexibility in design. Delamination is one of most common failure mechanisms for composite materials. By interleaving a nanofibrous mat between laminate plies it can be possible to control the interlaminar delamination strength. The nanofibrous mat at a laminate interface is impregnated by the resin during the curing process. In previous works, the authors tested delamination toughness and identified the cohesive zone properties of nanomats with varying fibre diameter, fiber arrangement (random, aligned) and mat thickness. The results showed that, by varying those parameters, a toughening or an embrittlement of the interface can be obtained. The modification induced by the nanomat can be therefore exploited in order to tailor the interply delamination strength of the laminate. The aim of this work is simulate the impact strength of a composite laminate giving different strength to interplies in order to proof that it is possible to increase the impact energy absorbed by the composite, in the perspective of optimization for use in impact attenuation.