Environmental Effects on Fracture Mechanical Properties of Polymer Composites

Delamination is a fairly common failure mechanism of composite materials due to their laminated nature. Like any other failure mode, delamination too is affected by environmental parameters that control the service conditions. This happens because a failure mode usually comprises a sequence of fracture processes that are sensitive to the interference of environmental parameters. This chapter addresses the question of environmental effects on delamination resistance. In particular, the effects of exposure to temperature, water and in-service fatigue on the fracture surface energy of delamination are discussed. Despite the wide range of materials for composite structures, attempts are made to interrelate environmental parameters with micromechanisms, and to propose general behaviour patterns.