Vulnerability of composite aircraft components to fragmenting warheads - experimental analysis, material modeling and numerical studies

Modern aircraft designs increasingly employ advanced composite materials for their primary structures, the most commonly used being Carbon Fibre Reinforced Plastics (CFRP). When subjected to blast and fragment impact e.g. by small calibre warheads, such structures demonstrate failure sensitivities and mechanisms which can be very different from those associated with "conventional" metallic components. The present study combines a programme of full-scale firing trials, non-destructive and structural testing with material characterisation and numerical simulations. Perforation statistics, strain gauge data and stiffness and strength degradation in compression after impact tests have been used to characterise the vulnerability of the structure. Comparison with three-dimensional hydrocode simulations using an accurate warhead model demonstrates the state of the art of finite element methods as an assessment tool for predicting the vulnerability of CFRP structures.