The Structure Design Analysis And Optimization Of Electric Vehicle Battery Box

With the energy shortage and environmental pollution problems becoming increasingly prominent, the development of electric vehicles is becoming increasingly fierce. Developing electric vehicles is an important way to promote sustainable development of the automotive industry. Battery pack of electric vehicles acts as the main source of energy, which directly affects the vehicle’s performance. As a power carrier, the battery case plays a key role in the security and guarding of battery power. So it has great significance of studying of power battery pack. This paper takes the battery pack of a pure electric vehicle as a research object, and the following aspects of the research work are carried out.Firstly, the design criteria and the requirements of the power battery box are described. Then, according to the existing vehicle body model, the arrangement and structure design of the battery box are conducted with CATIA. A preliminary finite element model of the new battery box is built by using Hyper Mesh, which sets a foundation for the further structural analysis and optimization of the power battery pack.Secondly, the static strength analysis and modal analysis of the power battery box are carried out by using Radioss. The result of the static strength analysis under typical operating conditions shows that the stress of battery bottom framework is smaller, which is far less than the yield strength of the material. The design of the bottom supporting frame of the battery box is too conservative and needs to be further optimized. The modal analysis result shows that the first six mode of the battery box are mainly the local vibration of the cover of the battery box, and the first order frequency is low. And it also shows that the strength of the cover is relatively inadequate, which provides an important reference for the following optimization.Thirdly, on the basis of the conclusion of the third chapter, the size optimization and shape optimization of the power battery box are carried out by Opti Struct. The batter box model is rebuilt based on the result of optimization, and then the finite element analysis is conducted. Compared with the result before optimization, the weight is lessened and the stiffness is obviously increased under the premise of satisfying the strength. The feasibility and effectiveness of the optimization are proved.Lastly, according to the existing random vibration standard of the power battery pack, the Nastran and Fatigue software are used to conduct the random vibration Fatigue analysis and predict the Fatigue life with the random vibration theory and the finite element method, which is valuable for engineering application.