某微型纯电动轿车正面碰撞安全仿真分析研究

发布时间：2018-08-13 08:59

【摘要】：当今,极端天气出现的频率不断增加,由此造成的损失越来越大,导致这些发生的重要原因就是人类活动造成的空气污染,汽车尾气的排放就是造成空气污染的其中一个主要原因,因此,人们更加倾向于更环保的纯电动汽车。随着纯电动汽车保有量的不断增加,如何提高纯电动汽车的安全性能成为研究人员的重点研究方向。参考传统燃油车每年交通事故造成的人员伤害和财产损失情况,纯电动汽车的安全性主要指的是碰撞安全性。本文旨在研究纯电动汽车的正面碰撞性能和纯电动汽车的轻量化问题,探讨如何在对纯电动汽车进行轻量化的同时不影响纯电动汽车的正面碰撞性能,以及纯电动汽车正面碰撞中的关键部件前纵梁的轻量化设计。本文建立了某款纯电动汽车的有限元模型,对其进行了正面碰撞仿真计算,将得到的仿真数据与试验数据相比较,判定模型的精确性,然后对正面碰撞的关键部件和数据进行详细的分析研究,初步掌握整车碰撞性能的好坏。针对前纵梁在碰撞过程中的较差表现,决定对前纵梁进行优化设计。本文运用了一种结合生产成本和乘员安全性的前纵梁轻量化优化设计方法。以前纵梁内板、外板和加强板为研究对象,将材料、厚度分别作为离散型、连续型设计变量,由于头部伤害指标值(HIC)是评价正面碰撞安全性的重要指标,因此选用材料成本以及HIC作为约束条件;最后,运用克里金法、遗传算法以及果蝇优化算法对前纵梁进行轻量化优化设计。确定优化方法后,先对比仿真模型加速度曲线与实车试验加速度曲线来验证模型的有效性,然后对前纵梁进行优化仿真计算。与优化前的前纵梁相比,经过优化后的前纵梁,乘员头部损伤指标值(HIC)降低0.9%,吸能性能提高了9.65%,质量减轻了11.05%,且前纵梁变形模式得到改善,在对前纵梁进行轻量化的同时也在一定程度上改善了车辆的正面碰撞安全性能。本文的研究成果对电动汽车其它部件的轻量化优化设计也具有参考意义。
[Abstract]:Today, the frequency of extreme weather is increasing and the resulting losses are increasing. The major cause of these events is air pollution caused by human activities. Automobile exhaust emissions are one of the main causes of air pollution, so people tend to more environmentally friendly pure electric vehicles. With the increasing number of pure electric vehicles, how to improve the safety performance of pure electric vehicles has become an important research direction. Referring to the personal injury and property loss caused by the traffic accidents caused by traditional fuel vehicles, the safety of pure electric vehicles mainly refers to the collision safety. The purpose of this paper is to study the frontal impact performance of pure electric vehicle and the lightweight problem of pure electric vehicle, and to discuss how to reduce the weight of pure electric vehicle without affecting the frontal impact performance of pure electric vehicle. And the lightweight design of front longitudinal beam, which is the key component in front impact of pure electric vehicle. In this paper, the finite element model of a pure electric vehicle is established, and the frontal impact simulation calculation is carried out. The simulation data obtained are compared with the experimental data to determine the accuracy of the model. Then, the key components and data of frontal impact are analyzed and studied in detail, and the impact performance of the whole vehicle is preliminarily grasped. In view of the poor performance of the front longitudinal beam in the process of collision, it is decided to optimize the design of the front longitudinal beam. In this paper, a lightweight optimization design method of front longitudinal beam is used, which combines production cost and crew safety. In the past, the inner, outer and stiffened plates of longitudinal beams were considered as discrete and continuous design variables. The head injury index (HIC) was an important index to evaluate the safety of frontal impact. Therefore, the material cost and HIC are chosen as the constraint conditions. Finally, the light weight optimization design of the front longitudinal beam is carried out by using Kriging method, genetic algorithm and Drosophila optimization algorithm. After the optimization method is determined, the effectiveness of the model is verified by comparing the acceleration curve of the simulation model with the acceleration curve of the real vehicle test, and then the optimization simulation of the front longitudinal beam is carried out. Compared with the front longitudinal beam before optimization, the head injury index value (HIC) of the crew member was decreased by 0.9%, the energy absorption performance was improved by 9.65%, the mass was reduced by 11.05%, and the deformation mode of the front longitudinal beam was improved. In addition to lightening the front longitudinal beam, the safety performance of vehicle frontal collision is improved to a certain extent. The research results of this paper also have reference significance for the light weight optimization design of other parts of electric vehicle.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U467.14

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