Structural Design And Optimization Of Carbon Fiber Reinforced Plastic Engine Hood

In recent years,with the fast development of national economy and the improvement of our living standard,automobile has become one of necessary parts in our life.It brings us many conveniences about traveling with the car ownership increasing,meanwhile,the question about energy and environment comes out,with higher demand.Vehicle weightless has become a important solution for above questions,the reduction of automotive weight not only can improve the performance of the automobile,but also can satisfy the demand of energy conservation and environment protection.Composite material becomes the perfect material for lightweight because of its advantages,such as,light weight,high specific strength,anti-corrosion,anti-fatigue,damping.This main aim is to apply the fibrous composite on auto-panel,researching on kinds of performance through the finite element simulation and sample test,discussing if possible that the composite material could take place of the steel.this dissertation also researches on the technology,resin transfer molding(RTM),for the production of composite parts.Based on above aims,four aspects of the research are carried out.Sectionl,taking the basic properties and price of fiber reinforcement into consideration,this paper uses carbon fiber and glass fiber reinforcement to design the lamination layer individually,to establish the finite element model of composite hood.By comparing the simulation results with steel parts,it is verified that the modal and stiffness of the composite hood can meet the design requirements.Through the trial of engine hood samples,manufactured according to the design scheme.verifying that various properties of carbon fiber composite materials engine hood meet the design requirements and lightweight effect is obvious.Section2,the paper will carry out the optimization design of the composite engine hood.Based on design scheme above,it will optimize the design of composite engine hood under the premise performance guaranteed.This paper uses two kinds of optimization methods,one is to optimize the ply thickness and angle of each single layer under the condition that the fiber single cut shape and the stacking sequence are unchanged.The other is to start with the shape of fiber cutting,through the conceptual design,system design and detailed design,to optimize the composite hood.Good optimization results are obtained through two optimization methods.Section 3,this paper has a research on pedestrian safety protection of composite engine hood.According to the laws,the pedestrian safety protection includes the impact test of the legs and the bumper,the head and the engine hood.In this paper,the head impact simulation is carried out to verify whether the composite hood meets the regulatory requirements.Section 4,the technology,resin transfer molding(RTDM),for the production of composite parts is studied.Through the finite element simulation,this paper researches on the effects of parameters,such as fiber permeability,resin injection temperature and injection pressure on the time,and then obtain a set of reasonable parameters.