摘要连杆作为发动机的关键传动机构之一，它连接着曲轴和活塞。在连杆运动的过程中， 承受着周期性交变的拉压载荷，受到极其复杂的力，所以连杆的安全性和可靠性在很大程 度上影响了柴油机的寿命。正因如此，发动机要求连杆具有足够的强度。84563

目前,有限元分析技术在对发动机零部件进行强度校核时，不仅精确程度高,还与实际 情况更为接近。因此，在本课题中，使用了有限元分析对连杆进行强度校核。首先，以 4L68 柴油机连杆的相关参数作为参考，利用Pro/E软件建立了连杆的三维实体模型，并进行了运 动学和动力学的相关计算；然后，在ANSYS中对模型进行网格的划分，约束和载荷的施加， 得到了连杆在最大压缩和最大拉伸两种工况下的应力、应变云图；最后，根据所得到的数 据，对连杆进行了强度校核，验证了连杆的可靠性和安全性。

毕业论文关键词：连杆；有限元分析；强度校核

Abstract The connecting rod is one of the key transmission mechanisms of the engine, which is connected with the crankshaft and the piston。 In the process of the connecting rod's motion, the connecting rod is subjected to the tension and compression load ,which is periodic and complicated。 So the safety and reliability of the connecting rod greatly influence the service life of the engine and the engine requires a connecting rod with sufficient strength。

At present, in the aspect of the strength check of the engine parts, the finite element analysis technology has high precision and it is close to the actual situation。 Therefore, the finite element analysis was used to check the strength of the connecting rod。 First, according to the relevant parameters of the 4L68 diesel engine's connecting rod, Pro / E was used to establish the 3D solid model of the connecting rod。 And the relevant calculation of the kinematics and dynamics has been finished。Then,ANSYS was used to mesh the model pision,apply the constraints and loads。 The distributions of the stress and strain when the connecting rod under the two conditions of the maximum compression and the maximum tensile have been obtained 。 Finally, according to the obtained data, the strength check of the connecting rod  has been finished and the reliability and safety of the connecting rod has been verified。

Key words: connecting rod; finite element analysis; strength check;

目 录

第一章 绪论 1

1。1 选题的目的和意义 1

1。2 国内外研究现状及存在的问题 1

1。3 主要研究内容 4

第二章 连杆的三维实体建模 5

2。1 Pro/E 简介 5

2。2 三维实体建模过程 5

2。3 本章小结 13

第三章 连杆载荷的计算 14

3。1 曲柄连杆机构的运动情况 14

3。2 4L68 柴油机主要性能参数 14

3。3 曲柄连杆机构中的作用力 15

3。4 连杆在两种工况下所受载荷 17

第四章 有限元分析 20

4。1 有限元分析与 ANSYS 20

4。2 边界条件的确定 21

4。3 最大压缩工况下 ANSYS 有限元分析 22

4。3。1 网格的划分