本文關(guān)鍵詞： 齒形配合面 微動疲勞損傷 有限元 裂紋預(yù)測　出處：《天津大學》2012年碩士論文　論文類型：學位論文

【摘要】：本文針對連桿齒形配合面在服役過程中過早出現(xiàn)裂紋的現(xiàn)象，從微動疲勞角度出發(fā)，進行裂紋萌生位置和擴展方向的觀察統(tǒng)計，并運用有限元軟件建立齒形配合面的接觸模型，展開應(yīng)力場與位移場的數(shù)值模擬和裂紋萌生位置的預(yù)測，最終提出減緩微動疲勞損傷的建議措施，，為工程應(yīng)用提供一定的理論依據(jù)。本文主要包括以下工作和研究成果： 1.對工程應(yīng)用中因齒形配合面發(fā)生失效的一批連桿進行裂紋位置的統(tǒng)計，得出損傷重點部位為齒形面；從某一典型失效連桿上切割得到齒形面部位，進行裂紋萌生位置和擴展方向的進一步觀察，總結(jié)微動疲勞損傷的特點；化學成分、力學性能和金相組織等一系列試驗檢測得到連桿材料性質(zhì)，其中力學性能為后續(xù)有限元分析提供數(shù)據(jù)支持。 2.根據(jù)連桿的動力學分析計算結(jié)果，應(yīng)用非線性有限元分析軟件ABAQUS對連桿進行多工況接觸分析；在全局模型的基礎(chǔ)上，運用子模型技術(shù)建立適于微動研究的齒形配合面精細有限元模型，分析齒面應(yīng)力、位移分布特點。 3.提出累計Ruiz準則法，考慮各個工況載荷大小和作用時間的不同進行加權(quán)，將單一工況的Ruiz準則統(tǒng)計值乘以相應(yīng)的加權(quán)系數(shù)，最終得到一個工作循環(huán)的累計微動疲勞損傷參數(shù)，在對比短臂端預(yù)測結(jié)果與實際損傷位置吻合程度較高后，進行了長臂端齒形面的裂紋位置預(yù)測，為連桿的改進設(shè)計和損傷評估提供參考。 4.針對螺栓預(yù)緊力、配合面摩擦系數(shù)、連桿結(jié)構(gòu)設(shè)計和表面工程，提出減緩齒形配合面微動損傷的改進措施，為工程應(yīng)用提供指導(dǎo)。
[Abstract]:In view of the phenomenon that cracks appear prematurely in the service process of the tooth fitting surface of connecting rod, from the angle of fretting fatigue, the observation and statistics of crack initiation position and propagation direction are carried out in this paper. The contact model of tooth fit surface is established by using finite element software, the numerical simulation of stress field and displacement field and the prediction of crack initiation position are carried out. Finally, the suggested measures to reduce fretting fatigue damage are put forward. This paper mainly includes the following work and research results: 1. According to the statistics of the crack position of a batch of connecting rods which have failure due to the failure of the tooth fitting surface in engineering application, it is concluded that the key site of the damage is the tooth shape surface; The tooth profile face position was obtained from the cutting of a typical failure connecting rod. The crack initiation position and propagation direction were observed further, and the characteristics of fretting fatigue damage were summarized. A series of tests such as chemical composition, mechanical properties and metallographic structure are used to test the properties of connecting rod materials, among which the mechanical properties provide data support for the subsequent finite element analysis. 2.According to the dynamic analysis results of the connecting rod, the contact analysis of the connecting rod under multiple working conditions is carried out by using the nonlinear finite element analysis software ABAQUS. On the basis of the global model, the fine finite element model of tooth fit surface is established by using submodel technique, and the distribution characteristics of stress and displacement of tooth surface are analyzed. 3. The accumulative Ruiz criterion method is put forward, considering the different load size and working time of each working condition, the statistical value of Ruiz criterion is multiplied by the corresponding weighting coefficient. Finally, the cumulative fretting fatigue damage parameters of a working cycle are obtained. After comparing the predicted results of short arm end with the actual damage location, the crack location of the tooth surface of the long arm end is predicted. It provides reference for the improved design and damage assessment of connecting rod. 4. Aiming at the pretightening force of bolt, friction coefficient of fit surface, design of connecting rod structure and surface engineering, the improvement measures of reducing fretting damage of tooth fitting face are put forward, which can provide guidance for engineering application.
【學位授予單位】：天津大學
【學位級別】：碩士
【學位授予年份】：2012
【分類號】：TH114;TH133.5

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相關(guān)期刊論文 前4條

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本文編號：1466664