Low energy impact behaviour of polyester-glass composites formed by resin transfer moulding

The impact behaviour of polyester-glass composites formed by resin transfer moulding has been studied to determine the effects of glass content, lamin ate thickness, and reinforcement geometry on damage developed during a low energy (9.56 J) subcritical impact. The force time responses of composites containing bidirectional and random reinforcements were analysed in terms o f an initiation and growth energy for delamination. All the materials exhib ited significant damage as a result of absorbed impact energy. The damage g enerated in the bidirectional composites was predominantly delamination and therefore these materials exhibited no significant reduction in post-impac t tensile strength. In contrast, the random composites exhibited significan t fibre fracture. with concomitant reductions in post-impact tensile streng th (>40%). The damage resistance of the bidirectional composites was quanti fied using impact energy/damage area ratios, but this approach was not appl icable to the random composites owing to the difference in the main damage mechanisms. PRCPA/1481 (C) 1998 The Institute of Materials.