| Thin-walled structures have been extensively studied as component with high energy absorption efficiency in the past decades,including their material composition and structures with better performance.Recently,as the control of fuel consumption poses greater challenges to automobile production and manufacturing,lightweight design has become one of the important means to improve the fuel efficiency.As one of the lightest materials with the best application prospects at present,carbon fiberreinforced polymer(CFRP)are gradually replacing traditional metal materials in automotive production for its high specific strength and specific stiffness.Compared with traditional metal materials,related research has proved that CFRP have a significant weight reduction effect.In order to combine the high specific strength and other properties of CFRP with the characteristics of low price and stable deformation of traditional metals,this paper carried out the research on the axial crushing performance of CFRP-metal hybrid square tube to improve the crashworthiness and lightweight effect of autobody,and apply it to the design of automobile.In this paper,the mechanical characteristics of aluminum alloy and carbon fiber reinforced polymer were first tested.The mechanical properties of the two materials were obtained as inputs for finite element analysis.The samples of CFRP-metal hybrid square tubes with unidirectional angle-ply and antisymmetric angle-ply were manufactured and the experiments of the tubes under axial quasi-static crushing were performed.The relationship between the deformation mode of and the layered form of CFRP-metal hybrid square tubes was analyzed and the axial crushing performance was compared with pure aluminum tube.The experimental results show that compared with pure aluminum tube and CFRP-metal hybrid square tubes with unidirectional angle-ply,CFRP-metal hybrid square tubes with antisymmetric angle-ply show stable axial crushing deformation and excellent energy absorption capacity,which improves the specific energy absorption by up to 11%.The finite element analysis software Ls-dyna was used to establish simulation models for the axial crushing of CFRP-metal hybrid square tubes with antisymmetric angle-ply.The mesh size,contact settings between aluminum alloy and CFRP,and non-physical parameters of the MAT54 material model were studied to simulate the behavior.The results are compared with experimental results to verify the accuracy of the simulation model.Based on the finite element model,the correlation between structure parameters of CFRPmetal hybrid square tubes with antisymmetric angle-ply and the axial crushing performance was studied.The results show that due to the existence of energy absorption through bending deformation,the increase of the total thickness lead to a monotonous increase in the SEA,and as the thickness ratio of CFRP to aluminum alloy increases,the SEA decreases first and then increases.On the premise of maintaining the same mass,as the proportion of CFRP increases,the SEA decreases first and then increases.When the number of CFRP layer is larger than a certain value,CFRP-metal hybrid square tubes with antisymmetric angle-ply shows a better energy absorption performance than pure aluminum tube of the same mass.Finally,the CFRP-metal hybrid square tubes with antisymmetric angle-ply were applied to the improved design of the energy absorption box of automobile.The simulation results show that energy absorption box made of CFRP-metal hybrid square tubes with antisymmetric angle-ply absorbed energy absorption 26.9% higher than that of the traditional metal on the premise of maintaining the same mass.The maximum acceleration of collision waveform is reduced by 8.49 g,and the automobile showed better quality of waveform.Compared with the traditional tube made of metal,CFRP-metal hybrid square tubes with antisymmetric angle-ply provides a good energy absorption performance,which will extend application of CFRP in the vehicle body. |
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