Crashworthiness of a composite fuselage barrel and related certification aspects: Evaluation of the passengers safety under critical drop test conditions by numerical simulations

The increasing use of composite materials in aviation has enabled the design of lighter and more performant aircraft, while maintaining passenger safety as a primary design criterion. However, the development of fully composite structures raises the need to thoroughly investigate their crashworthiness performance and the potential they may offer in impact scenarios. In this work, a composite fuselage barrel section has been modelled in Ls-Dyna to simulate different drop test scenarios. Specifically, several impact conditions have been analysed, varying both impact velocity and attitude to investigate the structural response of the composite fuselage and the passengers safety. The use of an Anthropomorphic Test Device enabled the evaluation of the lumbar load perceived by the occupant and its comparison with regulatory thresholds, above which severe spinal injuries may occur. The comparison of simulations results at different impact velocities, with zero pitch and roll angles, highlighted the effective crashworthy features of the composite structure and the ability to ensure occupant protection even under more demanding conditions than those required by certification standards. The comparison of simulations results with nonzero roll angles underlined the ability of the composite fuselage to withstand such impact conditions without compromising either its structural integrity or the safety of the passengers. Overall, results confirmed the capability of composite structures to provide efficient energy absorption during impact and effective occupant protection.