A Study On Structure Design Of Battery Pack And Collision Safety Based On Micro Electric Vehicle

With the increasing number of electric vehicle's inventory in China, more and more electric vehicle is counted into traffic security, and the collision will happened unavoidably. For the collision security of electric vehicle, we should not only meet the security standard of traditional fuel vehicle's collision, but also take the specific security problems that happened during collision process into consideration intensively. For example, in the process of power battery's collision, such phenomenon as vehicle fire, explosion, the electrolyte leakage,and high voltage short circuit may probably happened and cause great threat to passengers'security. Thus, it is extremely necessary to study the collision security of electric vehicle.This paper aims to design a battery pack that is suitable for the body structure of a blade electric vehicle (BEV), and verify the designing demand that meet the strength under two typical operating conditions. Besides, this paper also studies the vehicle's security in head-on and side collisions, providing theoretic basis for future electric vehicle's crash-worthiness design.This paper firstly establishes its 3D structure model in accordance with the principle of the battery pack design, and establishes mesh generation and finite element model upon the 3D structure. Besides, this paper analyzes two typical conditions according to automotive driving onto bumpy road and verify the designing demand that meet the strength of designed battery pack's structure.And then establishing the finite element model of vehicle's head-on collision in accordance with the regulatory requirements, and analyze its result on the premise of effective verification. The analytical result shows that the transformation of front longitudinal is not ideal and its endergonic effect is not good, besides the great transformation of front floor is bad for the protection of crew cabin and battery pack. In addition, both the battery pack's front displacement and body bracket's transformation are beyond the expected limit. Improving the weak parts of the vehicle in accordance with the analytical results, we could know by making before and after comparison that the optimization is so obvious that the regulatory requirements have been met generally.Finally establishing the finite model of side collision upon the basis of the finite element model in head-on collision, the paper analyzes intensively the transformation model, intrusion measurement and intrusion velocity of B-Pillar to verify whether the security regulations of side-collision can be met. The analytical results show that the transformation of automotive chassis is not obvious, which is good for the protection of battery pack. The transformation of B-Pillar cannot meet the designing demand. According to an ideal transformation model, we strengthen middle frontal parts of B-pillar, weaken the chassis. The optimizing results show that the transformation of B-Pillar's middle frontal parts have been decreased obviously and the transformation of chassis increase, which are in accordance with the model of ideal transformation.