Performance Research Of Light Composite Material For Railway Train Body

The lightweight design of the train body can greatly reduce the traction power of the train,thus reducing the difficulty of raising the speed of the train.Sandwich panel has the advantages of light weight,high bending stiffness and strength,high stability,heat insulation and noise absorption.As the body material of railway train,it can not only provide the rigidity and strength,but also reduce the weight of the body,and has the functions of flame retardant and noise absorption.Based on the aluminum panel / polyester(PET)foam sandwich structure,the bending resistance,local compression and impact properties of the sandwich panel were studied by means of experiment and simulation analysis.In order to obtain accurate material parameters to ensure the reliability of simulation analysis,tensile test on aluminum faceplate of sandwich panels was carried out.The elastic modulus,yield strength and true stress-strain curves of aluminum faceplate were obtained.Compression tests and shear tests were carried out on PET foam core,and the compressive strength,elastic modulus,shear modulus,shear strength,failure shear strain,compressive stress-strain curve and shear stress-strain curve of the core were obtained.Four kinds of sandwich panels were made for different tests.Three-point bending tests were carried out on four kinds of sandwich panels,and the load-displacement curves and deformation patterns were analyzed.The results show that the thickness of the faceplate mainly affects the load and overall deformation patterns of the sandwich panels,while the density of the core layer mainly affects the failure patterns of itself.The simulation analysis of sandwich panels with different faceplate thickness and core thickness shows that the average bending load of sandwich panel increases with the increase of the thickness of the faceplate and the thickness of the core layer.Considering the lightweight design of car body,the concept of specific load is introduced.It is found that the specific load of sandwich panel decreases first and then increases with the increase of panel thickness,and increases linearly with the increase of core thickness.Local quasi-static compression tests were carried out on three kinds of sandwich panels.The load-displacement curves and deformation patterns were analyzed.The results show that the thickness of the faceplate has a great influence on the load and the failure modes of the sandwich panels,while the core layer has little effect on the load and failure modes.The simulation results of sandwich panels with different faceplate thickness show that the average peak load and specific load of sandwich panels increase with the increase of panel thickness.Drop hammer impact tests were carried out on sandwich panels of two different specifications.Compared with local quasi-static compression,the load of sandwich panels increased significantly,and the failure mode changed fundamentally,mainly shear failure.The drop hammer impact process of sandwich panels at different impact velocities is simulated and analyzed.It is found that the load of sandwich panels increases with the increase of impact velocities.The composite roof model of tramcar based on sandwich plate is established.The finite element analysis of the composite roof model is carried out according to the loadbearing requirements of rail transit.The results show that the composite roof can meet the requirements of uniform load-bearing and local load-bearing.