强力旋压连杆衬套残余应力仿真及试验研究

发布时间：2018-03-23 21:40

本文选题：连杆衬套　切入点：强力旋压　出处：《中北大学》2017年硕士论文

【摘要】：柴油机连杆衬套在工作过程中主要受到两个力交替作用:气缸的爆发压力和连杆的惯性力,工作条件非常恶劣,且维修成本高,因此对连杆衬套的工作性能要求非常之高。经过强力旋压工艺加工的连杆衬套具有综合性能好、疲劳强度高、承载能力大等优点,因此,强力旋压工艺也被视为是柴油机连杆衬套的理想的加工工艺。但是,在强力旋压工艺进行连杆衬套的加工过程中,由于不同工艺参数、金属堆积、金属流动不均匀等各种可控以及不可控因素,导致加工后连杆衬套表面会产生残余应力。残余应力的存在则导致连杆衬套的尺寸精度、形状误差、疲劳强度、静强度、硬度等性能发生改变,进而影响到柴油机的使用寿命,因此,研究强力旋压加工后残余应力的分布规律、强力旋压工艺参数对残余应力的影响规律以及减小残余应力,对提高连杆衬套的使用寿命指导实际生产有着重要意义。本文以锡青铜(QSn7-0.2)为原材料,以强力旋压连杆衬套为研究对象,基于弹塑性有限元,对强力旋压加工过程以及加工后的连杆衬套表面残余应力进行有限元仿真。主要研究内容:(1)基于金属弹塑性有限元,采用ABAQUS有限元仿真软件,建立了三旋轮错距旋压的仿真模型,并进行了有限元仿真;(2)对连杆衬套的成形过程进行了分析,并对仿真成形过程中的轴向、周向、径向残余应力的形成过程进行了研究;(3)通过设计仿真方案并进行强力旋压成形过程的仿真,得到多组数据,基于此数据,分析了强力旋压工艺参数对残余应力的影响规律(4)通过设计正交试验,分析了强力旋压加工工艺参数对残余应力的影响顺序,并验证了仿真的可靠性。研究结果表明,减薄率、进给比以及主轴转度等工艺参数对连杆衬套表面残余应力有着重要影响,其中减薄率影响最为明显,通过ABAQUS可进行连杆衬套的成形过程仿真,可在实际生产中降低试验成本、节省时间。
[Abstract]:The connecting rod bushing of diesel engine is mainly subjected to two forces alternately in the working process: the burst pressure of the cylinder and the inertia force of the connecting rod, the working conditions are very bad, and the maintenance cost is high. Therefore, the working performance of the connecting rod bushing is very high. The connecting rod bushing processed by the strong spinning process has the advantages of good comprehensive performance, high fatigue strength, high bearing capacity and so on. The strong spinning process is also regarded as the ideal processing technology for the connecting rod bushing of diesel engine. However, during the processing of the connecting rod bushing in the strong spinning process, the metal accumulates due to the different technological parameters. Various controllable and uncontrollable factors, such as uneven metal flow, lead to residual stress on the surface of connecting rod bushing after machining. The existence of residual stress leads to dimensional accuracy, shape error, fatigue strength and static strength of connecting rod bushing. The hardness and other properties are changed, which will affect the service life of diesel engine. Therefore, the distribution law of residual stress after strong spinning, the influence of strength spinning process parameters on residual stress and the reduction of residual stress are studied. It is of great significance to improve the service life of connecting rod bushing and guide the practical production. In this paper, tin bronze QSn7-0.2) is used as raw material, and strong spinning link bushing is used as research object, based on elastic-plastic finite element method. The finite element simulation of the machining process and the surface residual stress of the connecting rod bushing is carried out. The main contents of this paper are as follows: (1) based on the metal elastoplastic finite element method, the ABAQUS finite element simulation software is used to simulate the residual stress of the connecting rod bushing. The simulation model of three-wheel offset spinning is established, and finite element simulation is carried out to analyze the forming process of connecting rod bushing, and the axial and circumferential directions in the simulation process are analyzed. The forming process of radial residual stress is studied. The influence of strength spinning process parameters on residual stress is analyzed. (4) by designing orthogonal test, the influence sequence of process parameters on residual stress is analyzed, and the reliability of simulation is verified. The research results show that the thinning rate is reduced. The feed ratio and spindle rotation have important influence on the surface residual stress of connecting rod bushing, among which the thinning rate is the most obvious. Through ABAQUS, the forming process of connecting rod bushing can be simulated, and the test cost can be reduced in actual production. Save time.
【学位授予单位】：中北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TK426;TG306

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