Influence of matrix ductility and fibre architecture on the repeated impact response of glass-fibre-reinforced composites

This paper describes the results of falling weight impact tests on glass-fibre-reinforced laminates. The test program consisted of (i) falling weight impact tests for the determination of the penetration energy and the influence of laminate construction on damage development and (ii) repeated falling weight impact tests for the determination of the impact fatigue life-time and damage development under repeated impact conditions at sub-penetration energy levels. The objective of this work is to compare the impact behaviour of cross-ply laminates based on a standard isophthalic unsaturated polyester and a rubber toughened vinyl ester resin and two types of glass reinforcement, i.e. a woven roving and a multiaxial fabric. The penetration energy of the various composite laminates appeared to be mainly influenced by the type of reinforcement, whereas damage development during (repeated) impact is strongly influenced by both fibre architecture and resin. No significant effect of the different material parameters investigated on the number of impacts to penetration (impact fatigue life-time) is observed. Especially when the repeated impact energy is normalized with respect to the penetration energy, all laminates showed similar behaviour.