Dynamic Simulation Analysis On Rigid-flex Coupling Model Of Electric Vehicle Based On Virtual Prototyping Technology

With the development of social economy and people's living standards,the automobile consumption requriement keeps increasing in China.Coupled with the rapid development of automotive technology in recent years,the customer's requirements for the car performance is also getting higher and higher.All of these have intensified the competition among car companies.How to quickly respond to market demand and develop high-quality and cheap car products in the shortest time as possible,has become the goal that major automobile companies have been pursuing.The emergence of virtual prototyping technology makes this goal become a reality.Virtual prototyping technology is a kind of technology that developed with the progress of computer technology.Its digital design method is based on the computer simulation analysis.In the early stages of product development before the physical prototype is manufactured,the product is digital designed and simulated.In order to achieve the goal of reducing the development cycle and costs as well as improving product quality,the performance of product will be measured,evaluated and optimized in advance.The study subject of this thesis is a new type of electric vehicle,which is being developed by a company.Unlike traditional car for its unique structural design,through the utilization of the mechanical system dyanmic simulation software ADAMS and the finite element analysis software HyperMesh in virtual prototyping technology to model,simulate and evaluate the dynamic performance of the vehicle.For the past optimize research work of vehicle dynamic performance,mostly just simply optimize a single performance indicator in handling stability or ride comfort.This thesis use orthogonal experimental design method and weighting matrix analysis to optimize these two performances at the same time.All of these will provide reference and guidance for the company in product development.The main work of this thesis is as follows:1.According to the unique structure type and designing of the new electric vehicle,the various parts of it have been reasonably simplified based on the fully consideration of the overall structure of the vehicle and the movement relationship among its various systems.The finite element model of the flexible axis considering the deformation effect of this vehicle model is established and the modal neutral file(MNF file)of the flexible axis is generated through modal analysis by using HyperMesh.Then the modal neutral file is imported into ADAMS / Car to establish the front and rear suspension subsystem model.After that,ADAMS / Car is used to establish the steering,braking,body system model and so on.Finally,all these subsystems model are assembled into rigid-flex coupling vehicle model through the information communicator between them.2.According to automotive performance test requirements and evaluation criteria formulated by the state,the simulation tests on handling stability,ride comfort and breaking have been carried out on the rigid-flex vehicle model through ADAMS / Car.3.The orthogonal design method is used to optimize the two objectives including handling stability and random input test on ride comfort.Several corresponding vehicle design parameters are selected as the influencing factors.The orthogonal test results are analyzed and the optimal combination of the level of different test factors is determined by matrix weighting analysis method.Through the optimal design of the relevant parameters,the handling stability and ride comfort of this electric vehicle have both been improved at the same time.