Energy Absorption Characteristics And Optimization Design Of CFRP Thin-walled Tube

The popularity of automobiles has brought many inevitable problems,such as frequent traffic accidents and environmental pollution.Carbon fiber reinforced composites have great potential application in the design of automotive structural parts due to their excellent characteristics of light weight and high strength.Studies have shown that CFRP thin-walled structures have several times the specific energy absorption of metals.Therefore,the study of the energy absorption characteristics of CFRP thin-walled tubes is of great significance for the design of automotive lightweight and automotive collision energy absorbing structure.Firstly,the energy absorption characteristics of CFRP thin-walled circular tubes under quasi-static compression conditions are studied by experiments and finite element simulations,and the two finite element modeling methods of single-layer shell elements and double-layer shell elements are used to verify the results.Secondly,the finite element simulation method is used to study the dynamic response of different CFRP thin-walled tubes under different loading conditions.The results show that the CFRP round tube has excellent comprehensive energy absorption characteristics under axial crushing conditions.Further analysis of the parameters of the CFRP tube found that the diameter of the circular tube and the thickness of the single-layer carbon fiber composite layer have a great influence on the specific energy absorption and peak force of the thin-walled tube,while the effect of the length was smaller.On this basis,a comparative study on the energy absorption characteristics of CFRP thin-walled cone tubes and round tubes under oblique crushing conditions was carried out.The results show that the existence of the loading angle changes the stress condition and failure mode of the thin-walled tube.The energy absorption indexes of the two thin-walled tubes become smaller with the increase of the loading angle,and the cone tube shows better energy absorption characteristics under the oblique crushing condition.Finally,based on the DOE and Kriging surrogate model method,the non-dominated sorting genetic algorithm NSGA-II is used to CFRP round tube under axial crushing condition and CFRP cone tube under single loading angle oblique crushing condition respectively.The energy absorption characteristics are optimized and the corresponding Pareto front is obtained.The multi-objective optimization work in this paper can provide a theoretical reference for the design of CFRP thin-walled structures in engineering practice.