Damage detection in glass fibre-reinforced plastic composites using self-sensing E-glassfibres

Abstract

The detection of damage in fibre-reinforced composite materials is important in areaswhere these materials are used for load-bearing applications. This paper reports on the useof conventional reinforcing E-glass fibres that were made to act as light guides. Thesereinforcing fibre light guides were used to detect damage induced in the composite byimpact, indentation and flexure. The E-glass fibres were converted into light guides byapplying an appropriate cladding material. The coating resins used in this study were anepoxy- and a polyurethane-based resin system. These self-sensing fibres or reinforcing fibrelight guides were surface mounted and also embedded at two specified locations within16-ply glass fibre-reinforced epoxy prepreg composites. The data generated in this studydemonstrated that the self-sensing concept could be used to study in situ and in realtime the failure processes in glass fibre-reinforced composites. A detailed studywas also undertaken to characterize the various failure modes observed when thecomposites with the self-sensing light guides were subjected to impact, indentationand flexural loading. The damaged areas in the composite were easily located bymeans of the ‘bleeding’ light emanating from the broken self-sensing E-glass fibres.