Response of composite panels subjected to varying impact energies

The advantages of using fiber reinforced plastics, composed of glass fibers embedded in a resin mix, for offshore structures and shipbuilding have been recognized for many years. These advantages include: (a) reduced weight, (b) better corrosion resistance, (c) lower life cycle costs, (d) no hot work required for retrofitting and (e) better thermal, acoustic and vibration properties. For naval vessels, they have the added advantages of lower signatures and the elimination of fatigue crack issues between steel decks and composite deckhouses. Despite this, their use on large scale structures as primary members has been restricted in the offshore industry. Naval applications have recently increased from the traditional mine countermeasure vessels to large hangers on destroyers. Many other naval applications are being proposed and a large volume of research is currently being undertaken. One of the drawbacks with composites is the lack of robust damage models applicable to large composite structures capable of reliably predicting damage growth and ultimate failure loads. This is particularly so in the prediction of delamination which can occur when composites are subjected to lateral impact or shock loads. The focus of this research is to examine the effects of low-velocity impact loading on the behavior of large-scale composite panels. Comparisons of the contact force and panel displacement are made using both an energy balance model and non-linear finite element analysis (FEA).