基于有限元法的农用车辆发动机连杆动静态态特性分析

连杆是农业车辆发动机的重要组成部分,由于农业车辆作业强度大,连杆作业过程中其结构、位移及应力变化严重影响作业性能。针对以上问题,本文以某厂生产的内燃机连杆为研究对象,利用三维建模软件NX10.0建立连杆组模型。采用有限元法对连杆杆身,大头轴瓦,小头衬套进行受力分析。研究表明:连杆受拉伸载荷时最大应力为199Mpa,受压缩载荷时最大应力为230Mpa,且在杆身两侧会发生翘曲变形,最大变形量为0.03mm。对连杆在自由模态和预应力模态下进行了动态特性分析,在设置了相同的接触条件和约束条件下,得到自由模态下前10阶的振型和预应力下前6阶的振型,发现变形总是在大、小头处,杆身与两端的过渡处,杆身的中间部位。本文研究结果为指导连杆组及发动机设计提供理论依据。

Analysis of Dynamic and Static Characteristics of Connecting Rods in Agricultural Vehicle Engines Based on Finite Element Method

The connecting rod is an important component of agricultural vehicle engines. Due to the high intensity of agricultural vehicle operation, the structural, displacement, and stress changes of the connecting rod during operation seriously affect the operational performance. In response to the above issues, this article takes the internal combustion engine connecting rod produced by a certain factory as the research object, and establishes a connecting rod group model using 3D modeling software NX10.0. Use finite element method to analyze the force on the connecting rod body, large end bearing shells, and small end bushings. Research shows that the maximum stress of the connecting rod under tensile load is 199Mpa, and the maximum stress under compressive load is 230Mpa. Warping deformation occurs on both sides of the rod, with a maximum deformation of 0.03mm. The dynamic characteristics of the connecting rod were analyzed in both free and prestressed modes. Under the same contact and constraint conditions, the first 10 modes of vibration in free mode and the first 6 modes of vibration in prestressed mode were obtained. It was found that the deformation always occurs at the large and small ends, the transition between the rod body and both ends, and the middle part of the rod body. The research results of this article provide a theoretical basis for guiding the design of connecting rod assemblies and engines.