| With the increasingly serious energy crisis and environmental pollution,new energy electric vehicles with zero emission and low noise have become the main development trend of the automobile industry.The design rationality of the powertrain suspension system of electric vehicles,which is a system for the elastic connection between the motor and reducer and the sub-frame,will directly affect the performance of the whole vehicle NVH(Noise,Vibration and Harshness,Noise,Vibration and comfort).At present,the research on the design method of powertrain suspension system of traditional fuel oil vehicle has been mature at home and abroad,but the research on the design of electric vehicle suspension system is still in the preliminary stage,and the analysis of the characteristics of pure electric vehicle suspension system has certain theoretical and application value.In this paper,the powertrain suspension system of a pure electric vehicle of a company is taken as the research object to study the characteristics of the suspension system of a pure electric vehicle and its influence on the performance of the whole vehicle NVH.The main research contents are as follows:This paper analyzes the research status of vehicle suspension system and the excitation of ev at home and abroad,and determines the layout plan of ev suspension system according to the basic theory of suspension vibration isolation,system design principle and characteristics of suspension element.The dynamic model of the 6-dof suspension system of the electric vehicle powertrain is established by using the method of Lagrange equation,the rigid body model mode of the powertrain is analyzed by using the method of multi-body dynamics and the numerical method respectively,and the natural frequency,main mode and decoupling rate of the first six orders of the original powertrain are determined.Aiming at the coupling vibration problem of decoupling rate in modal analysis of powertrain,the energy decoupling method is applied to improve thedecoupling rate of mounted system,and the multi-body dynamic method is used to optimize the system.Suspension system for optimization analysis for the nonlinear stiffness design,based on the working condition of gm,28,using the multi-body dynamics analyses some conditions of the powertrain mass center displacement and suspension center of elastic displacement,suspension force,at the same time,using the finite element analysis software to mount bracket for the static and dynamic analysis,to ensure that the suspension nonlinear stiffness and bracket design rationality.In order to design a reasonable mount sample loading Test,the amplitude of mount active and passive acceleration and in-car noise under WOT condition were collected by LMS.Scadas front end,and the collected data were analyzed by LMS Test.Lab. |
