Simulation Research For Composite Material Thin-Walled C-Channel Energy Absorption Characteristics

The crashworthiness is the most important property of aircraft to ensure the crew survival. Energy-absorbing structure under the aircraft floor is the main structure to decide the crashworthiness. High specific energy absorption characteristics of composite materials make it become the ideal material for the energy absorption structure and help to improve the crashworthiness. This paper studies the energy absorption characteristic of composite thin-walled C-channel and the crushing simulation method, and establishes the finite element model of the Wide-bodied aircraft fuselage and researched the feasibility of using the scaled model to assessment the crashworthiness of aircraft. The main work content is as follows:(1) The paper established quasi-static axial crushing simulation method of single shell element composite thin-walled C-channel with LS_DYNA modeling simulation software. Then the paper compared simulation results with the test data to verify the correctness of the simulation method. On this basis, the material parameters for the model was analyzed, the influence of failure trigger and loading rate to energy absorption characteristics was studied.(2) Quasi-static axial crushing simulation method of multilayer shell element composite thin-walled C-channel was created. It compared results with the test data and results of single shell element simulation method to verify the correctness of the multilayer shell element simulation method and the advantages and disadvantages. On this basis, the influence of loading rate to energy absorption characteristics and the energy absorption characteristics of different layer angle was studied.(3) On the basis of quasi-static axial crushing simulation method of single shell element composite thin-walled C-channel, the paper studied the energy absorption characteristics of the composites thin-walled C-channel dropped plies mechanism. Compared the results with SEA of the single shell element composite thin-walled C-channel, and assessed dropped plies mechanism.(4) Conducting the axial crushing simulation about the energy absorption structure with composite thin-walled C-channel as the main part. The reasonable simulation results proved that it’s feasible to apply the composites thin-walled C-channel to the lower part of the airplane floor structure.