Damage control using discrete thermoplastic film inserts

A technique for controlling delamination growth in a GFRP panel subjected to a low velocity impact is presented. Deploying discrete thermoplastic film rings at selective interfaces centred around the impact site has been shown to arrest delamination thus allowing damage control. Using six different layup configurations the thermoplastic film rings have been shown to suppress delamination crack growth at the desired interfaces. This resulted in manipulation of the damage footprint areas. Configurations that reduced delamination area by up to 38% demonstrated an improved CAI strength of up to 18% relative to a baseline panel. However, two configurations which saw an increase in delamination area by up to 30% showed similar CAI strengths to the baseline panel. This finding would confirm that it is the delamination interface location that influences the CAI strength not the damage footprint area.