极限工况下动力电池箱体结构设计和性能分析

Design and Performance Analysis of Power Battery Pack Structure Under Extreme Operating Conditions

动力电池是电动车辆的核心部件,电池箱体在确保动力电池的安全使用方面有着重要作用,特别是在恶劣工况条件下。以某型电池箱体为例,根据规范技术要求对其箱体布置和结构进行设计,运用三维CAD建立箱体数模,采用有限元方法对箱体在极限工况下的静态强度、刚度和模态特性进行分析。极限工况主要考虑:急转弯工况、急加速工况和急刹车工况。强度分析结果显示:该型箱体在极限工况下最大工作应力为64.67 MPa,远小于材料的屈服强度,最大变形量发生在箱体上盖,为0.076 9 mm,具有充足的刚度储备;模态分析结果显示:箱体的最小固有频率是57.30 Hz,避开了综合激励频率,在车辆行驶过程中不会产生共振。最后对该箱体结构的设计提出改进建议:该箱体存在优化空间,适于进一步开展轻量化设计;箱体上盖适宜增加加强筋进行强化,提高其刚度及抗振能力;箱体设计亟待进一步规范。

The power battery is the core component of electric vehicles,and the battery pack plays an important role in ensuring the safe use of the power battery,especially under harsh operating conditions.Taking a certain type of battery pack as an example,this paper designs the arrangement and structure of the pack based on the technical requirements of the specifications,establishes a three-dimensional CAD model of the pack,and analyzes its static strength,stiffness,and modal characteristics under extreme operating conditions using the finite element method.The extreme operating conditions mainly include sharp turns,rapid acceleration,and emergency braking.The strength analysis results show that the maximum working stress of the pack in extreme operating conditions is 64.67 MPa,far below the yield strength of the material,and the maximum displacement occurs on the top cover of the pack,which is 0.0769 mm,indicating sufficient reserve stiffness.The modal analysis results show that the minimum natural frequency of the pack is 57.30 Hz,avoiding the excitation frequency,thus preventing resonance during vehicle operation.Finally,improvement suggestions are made for the design of the pack structure:there is room for optimization in the pack structure,suitable for further lightweight design;reinforcing ribs should be added to strengthen the top cover of the pack to improve its stiffness and vibration resistance;and further standardization is needed for the pack design.