基于数值模拟的发动机连杆强度分析及结构改进

Strength Analysis and Structural Improvement of Engine Connecting Rod Based on Numerical Simulation

连杆是发动机的重要组成零件之一,在各种载荷的作用下,容易出现塑性变形、断裂而导致失效。为了分析连杆在工作过程中的应力大小及分布情况是否满足强度设计要求,通过SolidWorks软件建立了连杆的三维模型,将连杆的三维模型导入ANSYS Workbench中建立了连杆的结构力学有限元分析模型,并对其进行最大拉伸工况和最大压缩工况下的数值模拟分析。结果表明,连杆在最大拉伸工况下的最大等效应力大于材料的许用应力,需要对连杆结构进行改进,以满足连杆的强度设计要求。改进后,连杆最大拉伸工况下的最大等效应力由原来的392.16 MPa降低至223.38 MPa,下降43.04%,最大压缩工况下的最大等效应力由原来的164.02 MPa降低至160.68 MPa,下降2.04%。改进后的连杆在两种工况下的最大等效应力均小于材料的许用应力,满足了强度设计要求,该研究为发动机连杆或其他类似产品的结构设计提供了一种思路和方法。

The connecting rod is one of the important parts of the engine.Under the action of various loads,it is easy to appear plastic deformation and fracture,which resulting in failure.In order to analyze whether the stress size and distribution of connecting rod in working process meet the strength design requirements,the 3D model of the connecting rod is established by SolidWorks software,the 3D model is imported into ANSYS Workbench to establish the structural mechanics finite element model of the connecting rod,and the numerical simulation analysis is carried out under the maximum stretch and maximum compression working condition.The results show that the maximum equivalent stress of connecting rod under the maximum stretch working condition is out of the allowed stress of the material,it is necessary to improve the structure of connecting rod to meet the strength design requirements of connecting rod.The maximum equivalent stress of the improved connecting rod under the maximum stretch working condition is reduced from the original 392.16 MPa to the improved 223.38 MPa by 43.04%,the maximum equivalent stress under the maximum compression working condition is reduced from the original 164.02 MPa to the improved 160.68 MPa by 2.04%.The maximum equivalent stress of the improved connecting rod under two working conditions is less than the allowed stress of the material,which meet the strength design requirements.The research provides an idea and method for the structural design of engine connecting rod or other similar products.