柴油机连杆衬套微动特性研究-机械设计及理论专业论文 word格式.docx

Fretting Characteristics Analysis of Connecting Rod Bushing of Diesel Engine
Abstract
The connecting rod is acted upon by the alternating load of piston pin and inertia force of connecting rod during the running process of engine, The contact surface under the same contact pressure can produce the different degree of deformation resulting in two contact bodies mutual slip in the contact surface because the material character of connecting rod and bushing is different, it is called fretting. The fretting would not only cause fretting wear, but also cause fretting fatigue, which can leads to Interference of connecting rod bushing is insufficient. Insufficient Interference of connecting rod bushing can cause serious damage for engine. So, it is great significance for improving service life of bushing by finding the fretting characteristics of connecting rod bushing.
Combined with actual working condition of connecting rod and bushing of a certain type diesel engine, this paper simulates the contact process of the connecting rod and bushing by contact mechanics theory and finite element method for analyzing the fretting characteristics of bushing. The specific work is as follows:
(1)Access to a large number of literatures of fretting characteristic analysis, this paper
expounds the current status of development of the fretting. The key of research, analysis methods and the problems that need to be solved of this paper are decided.
(2) This paper summarizes structure and classification of the connecting rod bushing.
On the basis of the elastic contact theory, this paper analyses monly ball and plane contact model to get the theory resolution method of key parameters of fretting.
(3)This paper expounds finite element theory and algorithm of the contact problem. O ne
half of the solid model of connecting rod, bushings and piston pin are established, and the boundary conditions of model are ascertained. This paper analyzes the changing regularity of prehensive stre