Research on typical metal aircraft fuselage substructure crashworthy performance and designs

In order to study crashworthy performance and energy absorption characteristics of the aircraft fuselage substructure and carry out structural crashworthy design, this paper takes the typical metal aircraft as the object of study, and a typical fuselage substructure drop test was conducted. The energy-absorbing characteristics of the fuselage substructure were evaluated based on the experimental results and simulation analysis results. On this basis, the energy absorption design of fuselage substructure was carried out. The influence of the structural layout parameters of the new fuselage substructure on the crash response was studied through simulation analysis. The research results show that in the crash process of the original structure, the main energy absorption modes include plastic deformation and fracture after skin contact with the fuselage frame, plastic deformation and fracture of the column, frame and beam connection area, bending deformation of cabin floor beams and failure of the connectors. Since all the columns bend and break in the area near the connection area, the other areas of the column are almost not involved in plastic deformation. The energy absorption of the column is limited. The new substructure proposed in this paper has new configuration and also make full use of advantages of metal and composite materials. Compared with the original configuration, the deformation of new substructure proposed in this paper is more adequate while maintaining the same total mass of the fuselage structure. The peak load and acceleration at the early stage of the crash can be significantly reduced. The proportion of energy absorption by the frame and the energy-absorbing component has increased significantly. After optimization, the average overload of the new fuselage structure decreased by 30.8% compared with the original configuration, and the average acceleration of the two mass points on the cabin floor decreased by 25% and 37.6% respectively compared with the original configuration. The research results can provide a reference for the fuselage substructure crashworthy design.