Crashworthiness is one of the main concerns in civil aviation safety particularly with regard to the increasing ratio of carbon fiber reinforced plastic (CFRP) in aircraft primary structures. In order to generate dates for model validations, the mechanical properties of T700/3234 were obtained by material performance tests, and energy-absorbing results were gained by quasi-static crushing tests of composite sinusoidal specimens. The correctness of composite material model and single-layer finite element model of composite sinusoidal specimens were verified based on the simulation results and test results that were in good agreement. A typical civil aircraft fuselage section with composite sinusoidal specimens under cargo floor was suggested. The crashworthiness of finite element model of fuselage section was assessed by simulating the vertical drop test subjected to 7 m/s impact velocity, and the influences of different thickness of sub-floor composite sinusoidal specimens on crashworthiness of fuselage section were also analyzed. The simulation results show that the established finite element model can accurately simulate the crushing process of composite sinusoidal specimens; the failure process of fuselage section is more stable, and the safety of occupants can be effectively improved because of the smaller peak accelerations that was limited to human tolerance, a critical thickness of sub-floor composite sinusoidal specimens can restrict the magnitude of acceleration peaks, which has certain reference values for enhancing crashworthiness capabilities of fuselage section and improving the survivability of passengers.

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Crashworthiness design and certification have been and will continue to be the main concern in aviation safety. The influence of composite skin on crashworthiness of composite fuselage section was investigated in the paper. A finite element model of fuselage section was built, and the dynamic responding characteristics of composite fuselage section subjected to vertical impact velocity of 6.67 m/s were analysed by changing composite ply numbers and ply angles in the explicit finite element code LS-DYNA. The failure modes and acceleration response of fuselage section under different conditions were presented. The results show that the peak overload on the seat can be significantly reduced by selecting appropriate composite ply numbers and ply angles, and the crashworthiness of composite fuselage section can be efficiently improved.