Crashworthiness of Aircraft Composites Structures (Invited Talk)

More and more aircraft components are made of fiber reinforced composite material because of high stiffness, strength and low weight. These composites are made of glass or carbon fibers embedded into a polymer matrix. In some case, for equivalent energy absorption, composite components can be 50% lighter than steel components. The resistance of aircraft composite components to impact of various debris or birds must be assessed. Extensive literature exists describing the energy absorption mechanism of composite laminate tubes crushed between two rigid plates. Triggers are usually used to initiate material peeling inside and outside of the tube. The energy is absorbed by more complex mechanisms than for metallic tubes, such as delamination, fibers debonding, pulverization of material and friction. A constitutive model using damage mechanics is described in this paper. The model has been validated on composite tube crushing. This paper also describes the numerical results obtained with RADIOSS for the crash of composite sine wave beam and of sub cargo floor structure. Bird strike simulation results are also shown in the case of impact on a commuter leading edge structure. Comparison with tests results is shown. RADIOSS is an explicit finite element code developed by MECALOG, used for non linear simulations and validated industrially for crash analysis of metallic structures in automotive and aeronautic applications.