摘   要连杆是发动机的主要运动件，承担着将热能转化为机械能的核心任务，是最为重要的构件之一。发动机在工作时，连杆承受周期性的交变载荷而易产生疲劳破坏，疲劳破坏多表现为工作中突然性疲劳断裂。对摩托车而言，在行驶过程中发动机突然损坏会带给驾驶者生命危险。因此对连杆进行疲劳可靠性分析是十分必要的。86275

本文主要确定摩托车发动机连杆的结构和尺寸，并对发动机各工况下的连杆进行运动与受力分析；然后利用Pro/E软件对连杆进行三维建模，并将其导入ANSYS Workbench软件中，对极限工况下的连杆进行静力学分析，得到应力和总变形，分析得出连杆满足静强度要求，其危险部位主要在连杆小端孔内壁和小端与杆身的过渡区；再对连杆进行模态分析，计算分析连杆的固有频率，分析得到的模态频率及各阶振型；最后运用ANSYS Workbench中的Fatigue Tool对连杆小端最大拉伸和最大压缩工况进行疲劳可靠性分析，分析连杆的等效交变应力、损伤、疲劳安全系数、疲劳寿命和寿命疲劳敏感性，分析得出本文连杆不仅满足静强度要求，而且也满足疲劳强度要求。

毕业论文关键词：摩托车发动机；连杆；有限元分析；疲劳可靠性

Abstract The connecting rod is the main moving parts of engine, undertaking the central task of converting heat energy into mechanical energy, is one of the most important component。 When engine is at work, connecting rod is under periodic alternating load and easy to produce fatigue damage。 Fatigue damage often performance for sudden fatigue fracture。 For motorcycle, the damage in the process of working will bring the driver suddenly life risk, so fatigue reliability analysis of connecting rod is very necessary。

This article mainly determine the structure and size of motorcycle engine connecting rod, and engine connecting rod of movement and force analysis under various operating conditions; Then we use Pro/E software for 3 d modeling of connecting rod, import it into ANSYS Workbench, operate the statics analysis of limit condition of connecting rod, and get the stress nephogram and total deformation diagram, make sure that analysis connecting rod satisfies the requirement of static strength and the main dangerous parts are on the inner wall of the connecting rod small end and the transition zone of small end to shaft; Then carry out modal analysis on the connecting rod, calculate and analyze its natural frequencies and obtain the various order modal frequencies and vibration mode; Finally use the Fatigue Tool in ANSYS Workbench to operate Fatigue reliability analysis of connecting rod small end under the maximum tensile and the maximum compression, analyze the equivalent alternating stress, the damage, Fatigue safety factor, the Fatigue life and Fatigue sensitivity of life, and the analysis shows that the connecting rod not only meets the requirements of static strength, but also meets the requirements of fatigue strength。

Keywords: Motorcycle Engine; connecting rod; Finite Element Analysis; Fatigue Reliability

目  录

第一章 绪论 1

  1。1 选题的背景和研究意义 1

  1。2国内外研究现状 1

  1。3本文研究目的和内容 2

第二章 连杆的运动与受力分析 4

  2。1连杆的运动分析 4

   2。1。1连杆的角位移 5

   2。1。2连杆的角速度 6

   2。1。3连杆的角加速度