基于各向异性模型的电池包结构耐撞性分析

Analysis on crashworthiness of battery pack’s structure based on anisotropy model

对电池包箱体机械结构进行耐撞性分析和优化设计是提高电池包结构耐撞性的关键。文中基于各向异性理论,建立更加精细的18650单体电池有限元分析模型,开展试验验证了模型的有效性;结合电池单体各向异性模型,建立了含有电池包结构的电池包局部精细有限元分析模型,分析了异物冲击工况下箱体厚度、支架厚度对电池包冲击响应的影响;最后,采用灰色关联度方法,对箱体厚度、支架厚度、材料属性的灵敏度进行了分析。研究结果表明,增加箱体和支架厚度能有效降低物体侵入位移量、内部电池冲击力,电池包箱体材料属性和厚度是影响电池包能量吸收和冲击应力的关键参数。研究结果对动力电池包结构安全设计提供理论基础。

Crashworthiness analysis and optimization design of the mechanical structure of the battery pack’s box are the keys to improving crashworthiness of the battery pack’s structure.In this article,based on the theory of anisotropy,the finite-element model of the 18650 lithium-ion battery is set up,and some experiments are carried out to verify the whether the model is valid.In combination with the the battery cell’s anisotropy model,the finite-element model of the detailed parts of the battery pack;the analysis is conducted on the effect of box thickness and bracket thickness on the battery pack’s impact stress under the condition of impact load.Finally,the gray-correlation method is used to analyze sensitivity of box thickness,bracket thickness,and material properties.The results show that thanks to increased thickness and bracket thickness,the displacement due to the intruding objects and the impact stress of the internal battery can be effectively reduced..The material properties and thickness of the battery pack’s box are the key parameters that affect energy absorption and impact stress.This research provides theoretical reference for the structural safety design of those power-driven battery packs.