电动汽车动力电池箱结构稳健优化设计

发布时间：2018-01-12 18:43

本文关键词：电动汽车动力电池箱结构稳健优化设计　出处：《北京理工大学》2016年硕士论文　论文类型：学位论文

【摘要】：本文在汽车轻量化的大背景下,以某电动汽车动力电池箱为研究对象,基于有限元理论,综合运用拓扑优化和形貌优化技术,对动力电池箱结构进行了稳健优化设计,提高其动静态综合性能并且实现轻量化。主要研究内容和结论如下:首先,基于连续体结构拓扑优化方法基本理论,建立了动力电池箱有限元分析模型。分析总结了有限元建模过程中的关键技术,如模型简化、几何清理、网格划分规律及网格质量控制指标等,并针对焊接和螺栓连接等机械连接方式,对比讨论了其常用的模拟方式,最终建立了网格质量达到标准的有限元模型。其次,利用有限元分析方法对动力电池箱模态特性和静态特性进行分析。计算了电池箱的前六阶自由模态及约束模态,并对其模态特性进行了分析与评价;计算了电池箱在垂向颠簸、左转弯、右转弯、前进制动、倒车制动五种典型载荷工况下结构的应力、变形情况,并对其静态特性进行了分析与评价。然后,运用连续体结构拓扑优化方法,对动力电池箱进行确定性拓扑优化设计。针对单区域拓扑结构材料分布不理想的问题,利用多区域拓扑优化方法,提出四种分区方案,并分别进行动态、静态、多目标多区域拓扑优化。动态拓扑优化以提高结构前五阶固有频率为目标;静态拓扑优化以提高结构在五种典型载荷工况下的刚度为目标;动静态多目标拓扑优化以同时提高结构刚度和固有频率为目标,实现同时改善结构动静态性能的目的。最后,对动力电池箱进行稳健优化设计。提出了基于稀疏网格技术的稳健优化设计方法,并在概率论的基础上,将稳健设计问题的目标函数处理成目标性能均值与标准差的线性加权组合。针对三种精度等级情况,对电池箱进行了稳健拓扑优化计算,同时应用形貌优化技术,综合考虑加工工艺性要求,提出了两种加强筋布置方案,并重构模型,通过与动力电池箱原始结构进行动、静态性能对比,结果表明两种新结构在提高电池箱动、静态性能的同时实现了轻量化,减重达7~10%。
[Abstract]:In this paper, under the background of automobile lightweight, taking a power battery box of an electric vehicle as the research object, based on the finite element theory, the topology optimization and morphology optimization technology are used synthetically. Robust optimization design of power battery box structure is carried out to improve its dynamic and static performance and achieve lightweight. The main research contents and conclusions are as follows: firstly, based on the basic theory of topology optimization method of continuum structure. The finite element analysis model of power battery box is established, and the key technologies in the process of finite element modeling are analyzed and summarized, such as model simplification, geometric cleaning, mesh division rule and mesh quality control index, etc. According to the mechanical connection such as welding and bolt connection, the common simulation methods are compared and discussed. Finally, the finite element model of mesh quality is established. Secondly, the finite element model is established. The modal and static characteristics of power battery tank are analyzed by finite element method. The first six free modes and constrained modes are calculated, and the modal characteristics are analyzed and evaluated. The stress and deformation of the battery box under five typical load conditions, such as vertical jolt, left turn, right turn, forward brake and reverse braking, are calculated, and its static characteristics are analyzed and evaluated. The deterministic topology optimization design of power battery box is carried out by means of continuum structure topology optimization method. In order to solve the problem that the material distribution of single area topology structure is not ideal, the multi-region topology optimization method is used. Four partition schemes are proposed, and dynamic, static, multi-objective and multi-region topology optimization is carried out respectively. The dynamic topology optimization aims at increasing the first five natural frequencies of the structure. The aim of static topology optimization is to improve the stiffness of the structure under five typical load conditions. Dynamic and static multi-objective topology optimization aims at increasing the stiffness and natural frequency of the structure at the same time to achieve the purpose of simultaneously improving the dynamic and static performance of the structure. Finally. A robust optimization design method based on sparse grid technology is proposed and based on probability theory. The objective function of the robust design problem is treated as a linear weighted combination of the mean value and standard deviation of the target performance, and the robust topology optimization calculation of the battery box is carried out according to the three classes of accuracy. At the same time, using the topography optimization technology, considering the processing technology requirements, two reinforcement arrangement schemes are proposed, and the model is reconstructed, through the dynamic and static performance comparison with the original structure of the power battery box. The results show that the two new structures can improve the dynamic and static performance of the battery box and achieve lightweight, and the weight loss can be as high as 71010.
【学位授予单位】：北京理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U469.72

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