汽车尾门的轻量化设计开题报告

1. 研究目的与意义（文献综述）

the topic of this graduation design is "lightweight design of automobile tailgate". the purpose of this design is to realize the light weight of automobile body in tailgate by optimizing the design of automobile tailgate. due to the need of environmental protection and energy conservation, the lightweight of automobiles has become the development direction of automobiles in the world. on the premise of ensuring the strength and safety performance of the automobile, through the lightweight structural optimization design of the core components and the application of lightweight materials such as high-strength steel, aluminum/magnesium alloy, carbon fiber composite materials and advanced manufacturing and forming processes, the curb weight of the automobile is reduced as much as possible, thus improving the dynamic performance of the automobile, reducing fuel consumption and reducing exhaust pollution.

it can be seen that improving fuel economy is an inevitable development trend of automobiles. under the same technical conditions, the fuel consumption of automobiles has an obvious linear relationship with the vehicle weight. the fuel consumption of automobiles increases with the increase of the vehicle weight. therefore, adopting lightweight design for automobiles is undoubtedly a development direction to improve fuel economy ^[1]. according to the report of the world aluminum association, for every 10% reduction in the vehicle weight, the fuel consumption can be reduced by 6%~8%, and the emission can be reduced by about 4%. as an important part of the car body, the car door is also an independent assembly on the car body, which is a frequently used part of the car. the car body is directly related to the comfort and safety of passengers, so lightweight design of car doors is an effective method to reduce fuel consumption and carbon emissions on the premise of ensuring comfort and safety. the concept of light weight originates from racing, which brings good power and maneuverability with low weight, and is not aimed at fuel economy. later, with the proposal of energy saving and environmental protection, light weight is also widely applied to ordinary cars. today's car lightweight, of course, also includes the door lightweight, mainly from the structural optimization design, the application of lightweight materials and advanced manufacturing technology in three aspects ^[2]. in addition, the design of vehicle doors should be considered comprehensively from the aspects of safety and comfort.

structural optimization design technology for automobiles is the earliest and most mature lightweight technology at present. after 1970, u.s. general motors and other companies began to apply finite element analysis to automobile design. with the development of various technologies, cae technology has been increasingly applied in the field of automobiles ^[3]. xu xiaofeng used catia software to carry out door simulation analysis and verification to verify the design rationality of the door structure. through the simulation analysis of the door structure, the development cycle of the automobile appearance design can be effectively shortened and the development cost can be reduced ^[4]. li mengfan and others used hyperworks software to mesh the tailgate assembly with shell elements, and carried out free mode analysis, torsional stiffness analysis, dead weight analysis when fully opened, force analysis when closed and sag analysis ^[5]. at present, most of the methods used are the combination of size optimization, material optimization, topology optimization and multi-objective optimization. jianguang fang proposed a reliability-based multi-objective design optimization method to study the design of vehicle doors. response surface method was used instead of time-consuming finite element simulation, which improved the efficiency. monte carlo simulation and descriptive sampling technology were combined, and probability adequacy factor was used as the design constraint. multi-objective particle swarm optimization algorithm was adopted for optimization ^[6]. gao yunkai of tongji university ^[7] and deng junhong of south china university of technology ^[8] introduced in detail the application of multi-objective optimization in vehicle door lightweight design. most of zhen wang's researches on vehicle door lightweight were single-objective optimization, which not only realized lightweight, reduced 0.97kg, but also had good robustness ^[9]. hua huangwei of guangdong university of technology chose pure electric vehicle doors for lightweight design research and proposed a lightweight extension design method for doors to reduce the weight of doors and enrich the extension design theory and method system ^[10]. in terms of material optimization, xing haobin used composite materials for lightweight design of tailgate. the inner plate was made of pp lgf material, the outer plate was made of pp epdm td20 material, and the inner and outer plates were connected by polyurethane adhesive. compared to the sheet metal tailgate, there was no corrosion problem with the plastic tailgate, and the plastic tailgate showed stronger environmental adaptability. in addition, it has better elasticity and less damage under low-speed collision ^[11]. according to kang bin ^[12], the light-weight status of foreign automobiles was studied. at present, the proportion of high-strength steel and ultra-high-strength steel in automobile steel is increasing, while arcelormittal used high-strength steel to optimize the lightweight of many automobile parts. wang wei of chongqing jiaotong university used aluminum alloy to replace the ordinary steel plate of the inner and outer panels of the car door to carry out lightweight optimization ^[13]. in addition, novita sakundarini et al. adopted multi-material technology to realize light weight and cost control ^[14]. ulsac consortium used 6 kinds of high-strength steel and adopted traditional stamping technology to make high-quality door outer panel ^[15]. in addition, the multi-material connection technology researched by martin ivanjko^[16] et al. is a new type of lightweight connection technology. manufacturing lightweight refers to the adoption of appropriate manufacturing technology to reduce manufacturing steps and additional weight in the manufacturing process on the premise of certain body design and material lightweight. at present, many manufacturing technologies are widely used, such as laser tailor welding technology, hot forming technology of high strength steel, hydraulic forming technology, roll forming technology of high strength steel, surface cutting treatment technology, electromagnetic forming and other advanced joining and forming technologies.

2. 研究的基本内容与方案

2.1 basic contents of design

first of all, through the research and analysis of existing cars, determine the research benchmark. the design of the car tailgate and the drawing of the three-dimensional model should take into account the safety, comfort and other indicators in the process of establishing the three-dimensional model. the crashworthiness and light weight of the car door assembled by modeling are optimized, and the car door is further improved through finite element analysis.

3. 研究计划与安排

4. 参考文献（12篇以上）

[1]林程.汽车车身结构与设计[m].北京:机械工业出版社，2013.6.

[2]李永湘.汽车车门轻量化设计研究现状及其技术措施[j].贵州: 贵州工程应用技术学院，2019.2.

[3]范子杰.汽车轻量化技术的研究与进展[j].北京:清华大学，2014.1.