Abstract: In order to reduce the qualities of electric vehicles， the bearing characteristics of electric vehicle battery boxes were analyzed， based on the design method of rigidity equivalent， composite materials were used instead of metal materials based on the design method of rigidity equivalent.The laminated structure of the battery boxes was constructed by the theory of laminated structures of composite materials， the mechanics equations of equivalent stiffness and optimization functions were established and the structure parameters of the battery-boxes were determined.In order to verify the effectiveness of lightweight， the combination method of theoretical analysis and finite element numerical analysis was used， and the stiffnesses and deformations of metal materials and composite materials were compared.The results show that the method of equivalent stiffness is a convenience method for lightweight design of auto parts， and this method also provide references to the lightweight design for plate type parts of bearing structures.

Key words: lightweight, battery box, composite material, stiffness analysis, finite element analysis

摘要： 为了减小电动汽车车体的质量，分析了电动汽车电池盒的承载特点，基于刚度等效的设计方法，采用复合材料替代金属材料。应用复合材料的叠层结构力学理论对电池盒体进行叠层结构构建，建立了力学方程和优化方程，确定了复合材料电池盒的结构参数。为了验证轻量化效果，运用理论解析和有限元数值分析相结合的方法，对比了金属材料和复合材料的刚度和形变，研究结果表明：采用复合材料利用刚度等效设计法是对电动汽车零部件进行轻量化设计的有效途径，也可为汽车板型零件承载结构的轻量化设计提供借鉴。

关键词: 轻量化, 电池盒, 复合材料, 刚度分析, 有限元分析