STUDY ON ENERGY ABSORPTION CHARACTERISTICS OF THE SUB-CARGO FUSELAGE SECTION OF LARGE AIRCRAFTS

To study the energy absorption characteristics of sub-cargo fuselage section of a large passenger aircraft, based on the crash test that was carried out on the sub-cargo fuselage section with three frames and two spans, the detailed finite element model of the structure was established, and the crash dynamics simulation analysis was carried out. The deformation mode, key point displacement and fall velocity of the sub-cargo fuselage section were analyzed compared with the test results, and the energy absorption of each component was obtained. The results show that the overall stiffness of the finite element model of the sub-cargo fuselage section is basically the same as the test part, which verifies the accuracy of the finite element model and the material model. The model of vertical impact of sub-cargo fuselage section is established, and the equivalence of vertical impact and falling weight impact of the sub-cargo fuselage section is verified. At the same time, the vertical impact models (pitch 3°, 5°, 7°, 9°; roll 3°, 5°, 7°, 9°) of the sub-cargo fuselage section are established, and the influence of pitch and roll on the sub-cargo fuselage section is analyzed through deformation mode and energy absorption analysis. The results show that the pitch and roll of the sub-cargo fuselage section have great influence on the deformation and energy absorption of the frame assembly, the column and the beam. The study on the sub-cargo fuselage section can provide technical support for the design and analysis of the substructure of passenger floor.