【作者】 罗丹；

【导师】 陈吉清； 王玉超；

【作者基本信息】 华南理工大学 ， 工程硕士（专业学位）， 2017， 硕士

【摘要】 近年来由于汽车产量和保有量的日益上升,产生了交通堵塞、环境恶化、能源危机加重以及交通事故频发等一系列的问题,使得汽车对于节能、环保以及安全的需求日益增强。为改善这个现状,将以电动车为主的新能源汽车作为重要的发展方向。对于目前国内主流电动汽车,车身结构往往沿用同级别传统燃料汽车车身,但搭载动力电池后导致产品重量过大,续航里程无法满足需求且安全性较差,这是众多电动汽车产品不成功的原因之一,也是制约电动汽车推广的主要技术障碍。在这个大背景下,本文以现代汽车的开发流程及设计准则为基础,利用相关数学及商业软件工具,并应用轻质吸能材料铝合金、PDCPD和泡沫铝,设计开发了一款新能源车型的概念车,并对其性能进行验证。首先选定一款同级别的车型作为对标车,采用逆向工程的方法获取对标车的车身数据并建立有限元模型,通过车身结构的仿真模态与试验模态的对比,验证所建立的有限元模型的有效性,分析对标车白车身的刚度、轻量化水平及整车的碰撞安全性等性能,为新能源车型的概念开发设计提供参考数据;对新能源概念车的结构形式进行探讨,选择了桁架式的车身结构,根据整车的基本参数以及造型、电池的布置、动力系统及底盘等所确定的空间,利用拓扑优化的方法确定车身设计,对新能源概念车车身的刚度、模态以及轻量化水平等性能进行研究,并与对标车进行对比,为后期的详细设计提供参考;最后为提高整车的碰撞安全性,在铝合金空间框架式结构的前纵梁和门槛梁结构中填充泡沫铝,并对两结构方案进行多目标优化设计,填充泡沫铝后的优化方案相比对标车,车身质量只有对标车的47%,刚度和吸能能力有所提升,正面碰撞加速度峰值降低了31%。填充结构与未填充的原始结构相比,质量基本保持不变,正面和侧面碰撞的加速度峰值分别降低了5.4%和5.8%,说明泡沫铝应用于汽车的吸能结构,能够显著改善车辆的碰撞安全性。本文通过应用多种优化及分析技术,基本完成了一款满足轻质高强度吸能的新能源概念车结构的开发设计,并对其整车碰撞安全性进行了优化,对新能源汽车的结构设计优化有一定的借鉴意义。更多还原

【Abstract】 In recent years,the increasing production and ownership of vehicles lead to a series problems,such as traffic congestion,environmental degradation,energy crisis,traffic accidents and so on.So car’s demand for energy conservation,environmental protection and safety is strengthening.In order to improve this situation,all the countries take the new electric vehicles as the important development direction.The body structure of the current EV often follow the same form as conventional fuel vehicle body.So the mileage of EV is hard to meet the need of customer thanks to the high weight of battery.It makes many EV to become an unsuccessful products and also restricts the promotion of EV.Under this background,this paper development and design a electric concept vehicles based on the development process of the modern automobile body structure and automobile body structure design criteria,using relevant mathematical and commercial software tools.Validate the performance of the conceptual vehicle,which is designed by using lightweight and energy absorbing materials aluminum alloy,PDCPD and foamed aluminum.A standard car is selected to gain the body data and establish the finite element model of body structure using the method of reverse engineering.Compare the simulation modal with experimental modal of body structure to demonstrate the effectiveness of established model.Basis on this model,analysis static characteristics and collision safety performance to provide a reference for the concept development of the new energy vehicles.The forms of the new energy vehicles concept car’s body structure have been investigated,and the frame structure form is selected.By means of topology optimization,the body structure’s design space can be determined on the basis of the layout design,modeling and chassis systems.Compared the stiffness,modal and lightweight level performance of the new energy vehicles concept car with the standard car to provide a reference for detailed design of late.In order to improve the collision safety of vehicle,multi-objective optimization about filled aluminum foam in the front rail beam and threshold beam scheme is conducted.Finally,aluminum space frame structure filled with aluminum foam structure is designed.Compared to the standard form,the quality has decreased by 47% and the peak acceleration has decreased by 31%.Meanwhile,the specific energy absorption and stiffness can be promoted.Compared to the non-foam form,the peak acceleration has decreased by 5.4%.This illustrated that if aluminum foam materials are applied to energy absorption structures,the crash safety can be significantly improved and lightweight performance is also considered.To sum up,thisthesis bascically completed a new energy vehicle’s concept design and optimized collision safety of the vehicle by ueing a variety of optimization and analysis techniques.The structure and design method have reference significance on the new energy vehicles optimization design.更多还原