1. 研究目的与意义（文献综述）

1. background and significance of the research

in2012, the production of automobiles has exceeded 80 million (data from oica) ^[1].because of the nature of mass production in the automotive industry, everypenny saved in cost will make a considerable profit and every pound-forcereduced in weight will have a significant contribution in improving the fuel efficiencyand reducing the carbon emissions of the entire fleet of cars. with theincreasing energy shortage and intensifying of environmental pollution problemsin the world, the requirements for energy conservation and environmentalprotection of automobiles are also increasing. on the one hand, governments andautomobile manufacturers are vigorously promoting the research and developmentof new energy vehicles and electric vehicles. on the other hand, they alsoincrease investment in automotive lightweight technology ^[2]. theeffect of lightweight vehicles on energy conservation and emission reduction isdirect and significant. according to the statistics ofinternational authorities, about 60% of automobile fuel is consumed by theweight of the car. for every 10% reduction in vehicle quality, the fuel consumptioncan be reduced by 6%-8% ^[3]. at present, the lightweight design ofthe car is mainly positioned in the body structure and the chassis. the lightweightdesign of the metal parts for other parts is rarely noticed, and thelightweight design of cross car beam is also ignored. on the other hand, lightweightingalso plays an important role in improving vehicle handling performance,reducing vibration, shock and noise.

theinstrument panel beam assembly usually includes: the main beam of theinstrument panel (cross car beam referred to as ccb), the fixed bracketconnected to the vehicle body, the mounting bracket of the instrument paneltrim, the steering column mounting bracket, the airbag and the bracket. most ofthe cross car beams are always fixed on the main beam by welding. therefore,when optimizing the cross car beam, the cross car beam assembly is often seenas a cross car beam with several bracket connectors ^[4]. the structuralstrength of the driver and passengers in the car is the primary indicator ofits performance and the parameter that we need to pay attention to in ourlightweight design.

computer-aideddesign (cae) now occupies a high position in industrial practice. it mainlysimulates and optimizes products in the early stages of product design toimprove product design and improve product performance ^[5]. by usingcae to lightly design the cross car#8194;beam of the car, it can realize the overallstructural design, analyze the shape and thickness of the parts, and at thesame time perform modal analysis and stiffness strength analysis, which is veryconvenient and fast, and reduces development costs.

2. 研究的基本内容与方案

1.the main design content

inthis paper, the vehicle instrument panel beam is taken as the research object.the lightweight design of the cross car beam mainly adopts the method ofimproving the structure, and the variable section tube is used to replace theequal thickness tube. firstly, analyzing the design demand and performancedemand of the light truck cross car beam. and then, designing the light truck crosscar beam light weight structure design and drawing of the picture.

themain design contents are:

3. 研究计划与安排

accordingto the design situation, the design progress is as follows:

(1)7^th week of the semester 19-20: determine the graduation designtopic, improve the graduation design task book (related parameters), collectdata in school.

(2)first week of the 8^th semester: plan conception, literature search,completion of the opening report.

4. 参考文献（12篇以上）

[1] oica. organisationinternationale des constructeursd’automobiles.production

statistics, http://www.oica.net/category/production-statistics/ (10 march 2019).

[2] yang yanping，tang jie. china's automobilelightweight technology status and research focus [j]. cars and accessories, 2006, 42(20):20-22.