Lightweight Design Of Automobile Engine Hood

With the rapid development of society and economy,automobiles have gradually become an indispensable means of transportation for people’s daily lives.The consumption of energy by automobiles has also increased significantly,and the contradictions between automobiles and energy and environmental protection have become increasingly intensified.In order to solve these above-mentioned problems,the energy-saving and emissionreduction laws and regulations have been formulated by countries around the world.As far as the existing technical means are concerned,the lightweight design of automobiles is one of the effective ways to improve energy shortage and environmental pollution.However,lightweight design cannot be achieved at the expense of other performances.Therefore,how to achieve lightweight under the requirements of ensuring the performance of auto parts is one of the main problems that need to be faced in lightweight design.This paper takes the hood of a certain car as the research object.First,by discretizing the CAD geometric model of the hood,a reasonable way is selected to connect the mesh of the hood’s parts,the material properties of each part are analyzed,and by accurately assigned,the finite element model of the engine cover are achieved.At the same time,in accordance with the relevant specifications,a simulation model for the performance analysis of the hood is established in order to lay the foundation for subsequent analysis of the initial performance of the hood.Second,this paper analyzes the simulation results of various working conditions,and extracts the bending and torsional stiffness performance of the engine cover;strength performance;the first six free mode frequencies;and the pedestrian head protection performance in the initial state to determine the lightweight of the engine cover constraints and evaluation indicators.Third,this paper chooses 6061T6 aluminum alloy as the lightweight material for the inner and outer panels of the engine hood,carries out the lightweight design of aluminum alloy material for the engine hood,and determines the reference thickness of the aluminum alloy cover plate,so it can provides a reference for the subsequent multi-objective lightweight cover plate thickness design variables.Finally,based on the morphing function of Hypermesh,the cross-section size of the bonnet beam is modified.Isight software is used to build a multi-objective optimization platform for the bonnet.The bonnet structure is optimized and parameterized,and multiple software is used for co-simulation,and by combining with the optimization algorithm of Isight software to solve the optimal solution of the hood lightweight,and finally realize the lightweight design of the hood.The main research results obtained in this paper are as follows: 1.The finite element modeling process of engine hood is proposed,which can provide certain guidance for modeling of other engine hoods.2.Through theoretical analysis,the reference thickness of replacing the steel hood plate with aluminum hair hood plate is given,which provides a reference for the determination of the thickness of aluminum alloy materials.3.An automatic lightweight optimization process is built based on Isight,which can efficiently complete lightweight optimization.4.The material structure of the original engine hood is optimized,and the weight reduction effect of the engine hood is obvious.