Research On Lightweight Of Electric Vehicle Battery Box

Battery box is a loading component for the electric vehicle battery system.Its bearing severity is the key factor to the safety of the power battery.On the other hand,the lightweight design of electric vehicles is the efficient way to improve the efficiency of the battery.As the battery box have larger dimensions and heavier loads,so it’s structure need to meet the premise of strength and lightweight.Therefore,the composite material is applied to reduce the battery box weight and improve its stiffness,because the composite material has high specific strength and large specific modulus.In this paper,the metallic material is insteaded by composite material for battery box of a sanitation electric vehicle.The design method has been researched.Laminated composite plate is the basic structural element of the composite structure,and as the foundation of the design of the composite materials.In this paper,the battery box has been designed and optimized according to composite laminate strength and stiffness.According to the strength criterion of composite materials,the battery box strength as constraint conditions,on the basis of the elastic mechanical properties of the laminate,the total thickness of the composite laminates and the thickness of the single layer in the direction of each ply are assured.And four layer model of composite laminate is established,analysis of static structure strength of the battery box with four layer model to achieve optimal structure.Based on the car battery box in the process of moving over uneven road and turn to slam the brakes on two kinds of extreme stress conditions to analyze its structure strength.In order to improve its capacity to withstand dynamic load,the strength of the structure of the battery box is analyzed by using finite element software ABAQUS,the stress and strain results of each layer under dynamic loading are obtained,and the results provide the basis for the design of the structural stiffeners.At the same time,in order to improve the vibration characteristics of the battery box,the modal characteristics of the composite battery box are analyzed in ABAQUS,and the first six constrained modes of the box structure are obtained.By using the optimized design module in HyperWorks,the size parameters of the ribs are set and the shape of the structure is optimized.The whole structure of the composite battery box under dynamic and static conditions is obtained.In this paper,base on the finite element theory CAE analysis,using of composite materials instead of the traditional metal materials and optimization design methods to improve the existing battery box structure.In the enhanced battery box structure strength but also to improve the natural frequency of the plate,the dynamic characteristics of the battery box to is also improved,and reduce it’s 69.64% weight of its battery box,The method and the way of designing the composite battery case are explored.