Impact simulation and energy absorption characteristics investigation of composite fuselage structures

After the 7.9 m/s vertical drop anti-crash simulation of a full scale composite fuselage structure with energy-absorbing subfloor, the corresponding dynamic impact parameters of the average acceleration, velocity and impact force of the structure were obtained. Different assessment methods were considered to evaluate the crashworthiness characteristics of the structure. The full scale composite fuselage structure was divided into different sections in the design, and the energy-absorbing foam was added into the bottom structure of the fuselage section. The calculated results indicate that the crashworthiness design can meet the corresponding specifications. The impact simulation was carried out using the professional nonlinear explicit transient dynamic finite element software. Compared with the test results, the calculated average acceleration does not exceed 13g, with the relative error being less than 11%. The maximum vertical impact load is less than 6 kN, and the persistent time of the average minus acceleration of crash is not more than 0.03 s. All these results are reasonable. The model can be used for the anti-crash design of the helicopter.