目  錄

摘  要 I

ABSTRACT II

第一章 緒論 1

1.1 微型汽車的產(chǎn)生與發(fā)展 1

1.2微型汽車的特點(diǎn) 4

1.3本設(shè)計(jì)的主要內(nèi)容 5

第二章 車架概述 6

2.1車架的功用 6

2.2對(duì)車架的要求 6

2.3有車架與無(wú)車架結(jié)構(gòu)的比較 6

2.4作用在承載系統(tǒng)上的載荷 7

2.5承載系統(tǒng)的扭轉(zhuǎn)和彎曲剛度 9

2.6車架的類型 11

第三章 車架設(shè)計(jì) 15

3.1車架寬度的確定 15

3.2車架長(zhǎng)度的確定 15

3.3車架縱梁型式的確定 15

3.4車架橫梁型式的確定 16

3.5車架縱梁與橫梁連接型式的確定 17

3.6車架的制造工藝及材料 17

3.7車架的強(qiáng)度計(jì)算 18

3.7.1彎曲強(qiáng)度計(jì)算的基本假設(shè) 18

3.7.2縱梁的彎矩計(jì)算 18

        3.7.3縱梁、橫梁截面特性計(jì)算...................................................................20

3.7.4彎曲應(yīng)力計(jì)算 20

3.7.5臨界彎曲應(yīng)力的計(jì)算 21

3.7.6車架的剛度校核 21

第四章 用ANSYS分析車架 23

4.1ANSYS簡(jiǎn)介 23

4.2實(shí)體模型的建立 23

4.3有限元分析 24

4.3.1車架模型導(dǎo)入有限元軟件 24

4.3.2車架的網(wǎng)格劃分 25

4.3.3車架結(jié)構(gòu)的靜力性能分析 26

4.3.4分析結(jié)果 27

總  結(jié) 28

致  謝 29

參考文獻(xiàn).....................................................................................................................30

附  錄..........................................................................................................................31

摘  要

　　　　

　　　車架是汽車的重要部件，支承著發(fā)動(dòng)機(jī)、離合器、變速器、轉(zhuǎn)向器、駕駛室等所有簧上質(zhì)量的有關(guān)機(jī)件，承受著傳給它的各種力和力矩。車架應(yīng)有足夠的彎曲剛度，以使裝在其上的有關(guān)機(jī)構(gòu)之間的相對(duì)位置在汽車行駛過(guò)程中保持不變并使車身的變形最小；車架也應(yīng)有足夠的強(qiáng)度，以保證其有足夠的可靠性與壽命，縱梁等主要零件在使用期內(nèi)不應(yīng)有嚴(yán)重變形和開(kāi)裂。車架剛度不足會(huì)引起振動(dòng)和噪聲，也使得汽車的乘坐舒適性、操作穩(wěn)定性及某些機(jī)件的可靠性下降。但車架的扭轉(zhuǎn)剛度又不宜過(guò)大，否則將使車架和懸架系統(tǒng)的載荷增大并使汽車輪胎的接地性變差，使通過(guò)性變壞。

　　　本文通過(guò)參考同類型汽車設(shè)計(jì)一款適合廣大農(nóng)村用戶使用的微型轎車的車架。首先，介紹微型汽車的發(fā)展史和發(fā)展趨勢(shì)以及微型汽車的特點(diǎn)；其次，對(duì)車架進(jìn)行結(jié)構(gòu)設(shè)計(jì)，確定車架的主要參數(shù)，對(duì)車架進(jìn)行剛度校核；再次,對(duì)ANSYS軟件進(jìn)行了簡(jiǎn)單的介紹，利用Pro/e建立車架結(jié)構(gòu)的實(shí)體模型，將模型導(dǎo)入ANSYS中；最后，用ANSYS對(duì)車架模型進(jìn)行應(yīng)力分析。

　　　由于對(duì)車架的設(shè)計(jì)及有限元分析涉及的內(nèi)容很多，范圍較廣，受經(jīng)驗(yàn)、知識(shí)面及能力的限制，文中還存在一些不足之處，還需要進(jìn)一步加以完善。比如，在模型簡(jiǎn)化過(guò)程中，對(duì)縱梁上所有孔對(duì)車架的影響都沒(méi)有考慮，直接用鋼單元進(jìn)行單元的連接，沒(méi)有考慮到螺栓的柔度。所有這些簡(jiǎn)化對(duì)分析的結(jié)果存在一定的影響。

　　　

關(guān)鍵詞：汽車車架,彎曲剛度,車架模型，ANSYS，應(yīng)力分析 

　　　　

　　　　

　　　

　　　　ABSTRACT

　　　

　　　

　　　The frame，as a most important of a car,supports some accessories such as engine,clutch,gearbox,diverter,and withstands all kinds of force.The frame should have enough  flexural rigidity,so as to keep the related positions of some parts unchange while the car goes;There also should be enough intensity in the frame,so as to ensure its enough reliability and life-span,frame rigidity not only causes vibration and noise while being insufficient,but also makes the comfortableness of driving,stability of operation,reliability of some parts decline too.But the torsional rigidity of frame should not too big,otherwise it makes the load of the frame and hanging system enlarge.

　　　This article references the same type car to design a miniature car frame which suits the vast rural customers. First,this article introduces the history and development trends and characteristics of mini car； Secondly, the structure design of the frame is going, the main parameters of the frame is determined , the rigidity checking of the frame is done； Again,simply introducing the ANSYS , establishing the solid model of the frame with Pro/e and importing it into ANSYS；

Finally,goes ahead stress analysis of the frame model.

　　　Because of the frame design and finite element analysis invole in many contents, which is limited by the range of knowledge and experience and ability.This paper has some shortcomings which still need to be further perfected. For instance, in the process of the simplifying model,all the influences of longitudinal holes to frame are not considered, connect the units with steel unit directly without considering the flexibility of the bolt.All these simplifications will result in some influences to the anlysis.

KEY WORDS：car frame,flexural-rigidity,frame model,ANSYS, stress analysis