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

The results of falling wt. impact tests on glass fiber-reinforced laminates are described. The test program consisted of (i) falling wt. impact tests for the detn. of the penetration energy and the influence of laminate construction on damage development and (ii) repeated falling wt. impact tests for the detn. of the impact fatigue life-time and damage development under repeated impact conditions at sub-penetration energy levels. The impact behavior is compared for cross-ply laminates based on a std. isophthalic unsatd. 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 fiber architecture and resin. No significant effect of the different material parameters investigated on the no. of impacts to penetration (impact fatigue life-time) is obsd. Esp. when the repeated impact energy is normalized with respect to the penetration energy, all laminates showed similar behavio