Impact tests on VARTM fabricated woven roving vinyl ester laminates

Damage caused to composite marine vessels due to impact with floating debris is an important design consideration for modem vessels. Experimental results of small scale panels subjected to low velocity impact on Vacuum Assisted Resin Transfer Moulding (VARTM) produced specimens are presented. The effect of impactor size and kinetic energy are investigated. Damage was observed for all impact energies, in particular delamination on the back face. Comparison of the contact force and panel deflections are investigated using a simple analytical model based on a spring mass idealisation and a non-linear finite element analysis (FEA). The simple analytical model was found to give good correlation at low energy values despite the fact that only elastic behaviour was considered. The FEA model allowed for delamination, which was the dominant damage mechanism observed in the tests, using novel cohesive elements placed at natural resin rich layers throughout the thickness of the panels. Reasonable correlation with the damage patterns observed was obtained. Modifications to the model also are currently under investigation to improve the through thickness behaviour.