Impact damage processes in reinforced polymeric materials

This study investigates the impact toughness of two grades of Sheet Moulding Compound (SMC) and one grade of Glass Mat Thermoplastic (GMT) material. A servo-hydraulic impact machine and a drop-weight impact facility are used to obtain and relate different degrees of deformation and penetration damage of the two grades of SMC and GMT materials to load displacement records. The servo-hydraulic impact data provides a step-by-step damage history of drop-weight impact penetration of these materials. The impact energy absorbed by the different composite materials is determined for different degrees of deformation and penetration of the specimens. Notable in the findings is that, in some cases, the onset of through-thickness damage can occur before there is visual evidence of surface damage at the point of contact between the striker and the specimen. (C) 2003 Elsevier Science Ltd. All rights reserved.