Research On The Battery System Structural Design Of Electric Vehicle And Power Battery Collision Safety

With the continuous deterioration of the environment and energy issues,electric vehicles have become an important trend in the future development of the automotive industry.However,with the increase of its number,the accident of short-circuit and fire after the collision of electric vehicles has gradually increased in recent years,which has brought certain negative impacts on the popularization of electric vehicles and restricted it’s normal development.Therefore,the research on the collision safety of electric vehicles is of great significance.As the core component of electric vehicles,power batteries are critical to their safety in collisions.At present,foreign scholars have studied the mechanical properties and mechanical short circuit of power batteries.However,domestic scholars mostly use concentrated mass points or rigid bodies to simulate power batteries and modules when conducting electric vehicle crash research and rarely consider the collision short-circuit failure.Research on the optimization of electric vehicle battery system and body structure mainly focuses on static and dynamic stiffness,front impact,rear collision and side collision,while lesson the pole side impact.The research on this form of severe collision is more focused on traditional car.In response to the above questions,this paper introduces the short-circuit failure analysis of power battery into electric vehicle crash research,and optimizes the battery system structure of the electric vehicle by using dynamic topology optimization and orthogonal experiment method for each collision,especially the side column collision condition.In this paper,the mechanical short circuit prediction model of power battery is established and applied to the collision of electric vehicle,such as front impact,offset collision,side collision and pole side impact,to study the deformation and short circuit conditions of power battery under collision.The collision results show that the structure of the battery system is less deformed under other collisions of the electric vehicle,but the structural deformation of the battery system is bad after the pole side impact,and a lot of batteries are invalid.Therefore,the dynamic topology optimization and orthogonal test method are used to redesign the skeletal structure of the electric vehicle battery system for the pole side impact,and a new battery system structure with better bearing path and thickness distribution is obtained.Then the newbattery system structure is installed in the whole vehicle to check and further optimize in all the collisions,and finally a new battery system structure which can protect battery well under all collision conditions is obtained.Compared with the original structure,the new battery system structure greatly reduces the structural deformation of the battery system and the short circuit failure of the battery without increasing the weight.The battery failure ratio of the side column collision on the weakest position was reduced from 8.56% to 3.51%,the cylindrical intrusion amount was reduced from 123.1mm to 35.70 mm,and the battery failure and intrusion amount of the other four side column collision positions were also significantly reduced.The battery failure ratio under the frontal 40% overlap deformable barrier collision decreased from 1.78% to 0.68%,and the intrusion amount decreased from 18.01 mm to 9.12 mm.The structural deformation of the battery system under the collisions which include the frontal collision,offset collision,side collision and side column collision condition is small,the proportion of battery collision failure is less than 4%,and the probability of occurrence of short circuit or even fire is small.