Load-bearing Analysis Of Composite Honeycomb Sandwich Vehicle Body Floor

The lightweight design of vehicle body is an important means to achieve sustainable development in the field of rail transit.The application of new materials and new structures is an important way to realize the lightweight of vehicle body.Composite honeycomb sandwich structure is widely used in lightweight design of vehicle body due to its excellent mechanical properties and strong designability.The traditional vehicle body floor structure is difficult to meet the growing demand for lightweight.In this paper,the floor structure of high-speed train body is taken as the research object,and the carbon fiber/aluminum honeycomb sandwich structure is used for lightweight design.The main work contents are as follows :Firstly,the out-of-plane quasi-static compression test of aluminum honeycomb with different structural parameters was carried out by SHIMADZU universal testing machine.The effects of height and relative density on the out-of-plane quasi-static compression performance of aluminum honeycomb were studied.It was found that the relative density had a great influence on the out-of-plane quasi-static compression performance of aluminum honeycomb,while the height had little effect on it.At the same time,the out-of-plane quasi-static compression simulation model of aluminum honeycomb is established.In order to verify the reliability of the simulation model,the results are compared with the test,and the results are in good agreement.Secondly,based on the Hashin failure criterion,the corresponding simulation model is established for the quasi-static three-point bending test of carbon fiber/aluminum honeycomb sandwich panel in the literature.The accuracy of the finite element model was verified by comparing the curve trend,deformation mode,peak load and energy absorption between the simulation results and the test results.The finite element simulation model of carbon fiber/aluminum honeycomb sandwich structure under bending load was obtained.Finally,combined with the actual floor structure layout of high-speed train,the sub-region is selected.Based on the out-of-plane quasi-static compression performance of aluminum honeycomb and the three-point bending simulation model of carbon fiber/aluminum honeycomb sandwich panel,the simulation model of carbon fiber/aluminum honeycomb sandwich floor is established.The bearing capacity of the floor under uniformly distributed load and concentrated load is analyzed,and its influencing factors are discussed.The results show that the carbon fiber/aluminum honeycomb sandwich floor has a weight loss of 45.23% compared with the original CRH5 vehicle floor structure,and meets the strength requirements under both working conditions.Changing the honeycomb wall thickness and panel thickness distribution can improve the floor bearing capacity.