Optimal Design Of CFRP Typical Body Parts For An Electric Vehicle

With the vigorous implementation of national policies and regulations such as energy saving and emission reduction,electric vehicles have gradually become the emerging mainstream in the development of the automotive industry.However,the limitation of battery life has been the main reason to hinder electric vehicles’ development and popularization.Lightweight has become a top priority,and as the way of lightweighting structures gradually approaches saturation,the lightweight by materials has gradually become one of the main ways to help the development of electric vehicles.For the application of CFRP in electric vehicles,with the higher specific strength,lower density and more excellent designable performance,the automotive industry and composite material related scientific research institutions have expressed high affirmation and expectations.At present,due to the complexity of CFRP design and the limitation of simulation accuracy and failure mode,A lot of automobile companies use the way of trial and error to design the vehicle body composite parts,which can not give full play to the excellent performance of the CFRP material and realize the integrated design of material and performance.Therefore,it is necessary to study the method of the vehicle body CFRP parts optimization.In this paper,the structure analysis,dynamic side impact performance and static bending and torsion stiffness of an electric vehicle are carried out,and the initial performance of the electric vehicle is obtained.Then the tensile,shear,compression and drop hammer impact tests of T300 CFRP are carried out according to ASTM series standards,and the mechanical behavior simulation and prediction technology is used to obtain the CFRP performance and finite element modeling.The validity of CFRP modeling simulation is confirmed.Based on the analysis of the initial floor performance by the finite element software,the electric vehicle components are decoupled to obtain the substructure component with high optimization efficiency.According to the main static bending and torsion stress conditions,the three-step process of free size optimization,size optimization and ply sequence optimization is used to optimize,and the engineering process is combined with the process.The results show that the lightweight effect is more than 50% on the basis of meeting the performance requirements.The B-pillar reinforced plate is optimized on the basis of considering the side impact condition,and the dynamic process of impact is equivalent to static force.After three-step optimization method,the optimized scheme of CFRP B-pillar reinforced plate is finally obtained.The effect of weight loss more than 70% is achieved.Compared with traditional metal materials,the cost of carbon fiber composite is higher,but its designability is surprising.It has great potential in automobile application,but it is limited to simulation,optimization and production,so it cannot be used on a large scale.In this paper,through the optimization and engineering interpretation design of the vehicle parts under different main stress conditions combined with the characteristics of CFRP,the parts meeting the performance requirements are obtained,and the excellent lightweight effect is achieved.In this paper,the optimization method of CFRP is studied,which provides a reference for the application of composite materials in body parts.