Damage resistance and low-velocity impact behaviour of hybrid composite laminates with multiple thin steel and elastomer layers

In the presented investigation composites consisting of carbon and glass fiber reinforced plastics in combination with steel and elastomer layers are subjected to experimental drop-weight impact tests and compression after impact tests. The objective is to study the low-velocity impact behaviour, damage resistance and residual strength of composite laminates dependent on position and proportion of additional layers. In continuation of earlier studies two additional laminate configurations containing thin steel layers and two elastomer layers are tested. Impact damage and damage tolerance are determined respecting the aspect of differing bending stiffnesses and structure densities. It is found that concerning the elastomer addition the damage area, which mainly depends on the elastomer layer position, is an essential influencing factor on the residual strength. The steel addition leads to wide delaminations but high residual strengths.