Selection of patch and adhesive materials for helicopter battle damage repair applications

The rapid repair of battle damage to composite aircraft structure has been investigated by Defence Science and Technology Organisation and Cooperative Research Centre for Advanced Composite Structures, Australia. Part of this investigation was to select candidate composite repair materials. The material systems considered require a long shelf life, high mechanical performance and the ability to be processed in the field or at depot with minimum equipment. The material system must also be able to withstand elevated temperature environment without significant degradation in repair performance. Several candidate adhesive and patch material systems were investigated including two-part adhesive epoxy resin and dry fabric for wet-layup applications, room temperature curing acrylic adhesive and room temperature storage epoxy resin/prepreg material systems. A series of material property characterisation tests were carried out to evaluate the performance of these materials. Test results showed that these materials could be applied in various situations for battle damage repair (BDR). The property data generated from these tests may be used in BDR design analyses.