Crashworthiness Study of a Newly Developed Civil Aircraft Fuselage Section with Auxiliary Fuel Tank Reinforced with Composite Foam

Abstract

Over the past two decades, aircraft crashworthiness has seen major developments, mainly with modern computing systems and commercial finite element (FE) codes. The structure and the material have been designed to absorb more kinetic energy to ensure enough safety during a controlled crash condition. However, the fuselage section with an onboard auxiliary fuel tank requires special arrangements, since the inclined strut system with an efficient energy absorber is difficult to install under the cabin floor due to the space occupied by the fuel tank. To solve this shortcoming, a PVC composite foam along with an aluminum plate is introduced beneath the fuel tank to improve the crashworthiness metrics of the fuselage. Drop tests for both the conventional design and the proposed model are investigated by adopting the nonlinear explicit dynamics code Ansys Autodyn, with an impact velocity of 9.14 m/s. It was found that the kinetic energy absorption of the original fuselage section can be improved by 3.54% by reinforcing the foam and the plate. Moreover, they contribute to 20% of total internal energy dissipation. Numerical outcomes also suggest that the cabin floor surface experiences a 41% lower maximum stress, in addition to the mitigation of the maximum peak acceleration responses of the cabin floor at different measured locations from 6% to 36%.