【摘要】：磨合是機(jī)器系統(tǒng)必須經(jīng)歷的重要磨損階段,磨合磨損是機(jī)加工表面經(jīng)過動態(tài)磨損達(dá)到穩(wěn)定低磨損率表面的過程,它對防止發(fā)生咬合、獲得低磨損率的穩(wěn)定持續(xù)工作狀態(tài)、延長使用壽命等都有重要影響。摩擦副表面形貌變化是磨合過程中的重要特征表現(xiàn),磨合后表面形貌直接影響摩擦副穩(wěn)定工作狀態(tài)下的性能。此外,與穩(wěn)定磨損相比,磨合過程磨損量大,磨合磨損量直接影響摩擦副的使用壽命。由于滑動摩擦過程中摩擦副表面接觸面積較大,表面形貌對滑動摩擦副的影響較為顯著。探討滑動摩擦副磨合磨損表面形貌的變化規(guī)律,研究磨合磨損前后摩擦副表面形貌的關(guān)聯(lián)關(guān)系,研究基于磨合前初始表面形貌的磨合磨損特性包括磨合后表面形貌與磨損量的預(yù)測理論和方法,對于摩擦副表面形貌優(yōu)化設(shè)計(jì),以保證摩擦副工作性能、和使用壽命都具有重要意義。本文主要工作與創(chuàng)新如下： 以接觸力學(xué)為理論基礎(chǔ),建立了滑動摩擦副的磨合磨損解析模型�；诮佑|力學(xué)與混合潤滑特征,依據(jù)Greenwood-Williamson摩擦模型與表面微形貌凸峰結(jié)構(gòu)受力原理,同時(shí)考慮摩擦副黏著接觸,并以摩擦系數(shù)穩(wěn)定為磨合結(jié)束判據(jù),提出并建立了一種基于滑動摩擦副的磨合磨損解析模型。 理論和實(shí)驗(yàn)論證了滑動摩擦副磨合前后表面形貌的相關(guān)性,為基于摩擦副表面形貌的磨合磨損特性預(yù)測提供了依據(jù)�；谀ズ夏p解析模型,模擬磨合磨損過程并分析表面形貌的變化規(guī)律,論證了磨合前后表面形貌的相關(guān)性。同時(shí),試驗(yàn)分析了不同工況與初始表面形貌對磨合后表面形貌的影響,實(shí)驗(yàn)驗(yàn)證了磨合前后表面形貌的相關(guān)性。 基于最大相關(guān)最小冗余特征選擇方法,提出了磨合磨損預(yù)測模型的表面形貌特征參數(shù)有效提取方法。由于區(qū)域法表面形貌評定參數(shù)眾多,將全部參數(shù)進(jìn)行磨合磨損預(yù)測建模不但使模型復(fù)雜度過高,且勢必造成表面表征的冗余性,因而,必須對區(qū)域法表面形貌評定參數(shù)進(jìn)行選擇,提取出與磨合磨損特性相關(guān)的特征參數(shù)。通過區(qū)域法表面形貌評定參數(shù)的特性分析,本文提出了基于最大相關(guān)最小冗余特征選擇,面向磨合磨損預(yù)測模型的特征參數(shù)集合的有效提取方法。 提出了基于最小二乘支持向量機(jī),建立磨合磨損特性包括表面形貌與磨損量預(yù)測模型的有效建模方法。根據(jù)提取到的表面形貌特征參數(shù)集合,建立能夠預(yù)測磨合表面形貌參數(shù)與磨合磨損量的磨合磨損預(yù)測模型。該方法基于磨合前后表面形貌的相關(guān)性論證結(jié)論,考慮到解析磨合模型不能有效表征磨合過程的復(fù)雜性,將磨合過程作為黑箱過程進(jìn)行機(jī)器學(xué)習(xí),避免由于對磨合過程的簡化造成的偏差,建立磨合過程輸入變量(工況與表面形貌)與磨合過程輸出變量(表面形貌或磨合磨損量)之間的相互關(guān)系,以實(shí)現(xiàn)基于摩擦副表面形貌的磨合磨損特性預(yù)測。。 實(shí)驗(yàn)測試驗(yàn)證了磨合磨損特性預(yù)測建模方法的有效性和準(zhǔn)確性。
[Abstract]:Running-in is an important wear stage that the machine system must go through. Running-in wear is a process in which the machined surface achieves a stable low wear rate surface through dynamic wear. It has an important influence on preventing occlusion, obtaining a stable and continuous working state with low wear rate and prolonging service life. In addition, compared with stable wear, the wear amount during running-in process is larger, and the wear amount during running-in directly affects the service life of the friction pair. The relationship between the surface topography of friction pairs before and after running-in wear is studied. The theory and method of predicting the surface topography and wear amount after running-in based on the initial surface topography before running-in wear are studied. In order to ensure the working performance and service life of the friction pair, the design is of great significance.
On the basis of contact mechanics, an analytical model of running-in wear of sliding friction pairs is established. Based on contact mechanics and mixed lubrication characteristics, according to Greenwood-Williamson friction model and the stress principle of surface micro-topography convex structure, the adhesive contact of friction pairs is considered, and the stability of friction coefficient is taken as the end criterion of running-in. An analytical model of running in wear based on sliding friction pair is presented.
The correlation between the surface topography of sliding friction pairs before and after running-in is theoretically and experimentally demonstrated, which provides a basis for predicting the running-in wear characteristics based on the surface topography of sliding friction pairs. The influence of different working conditions and initial surface morphology on the surface morphology after running-in was analyzed. The correlation between the surface morphology before and after running-in was verified by experiments.
Based on the method of maximum correlation and minimum redundancy feature selection, an effective method for extracting surface topography parameters of wear prediction model is proposed. It is necessary to select the parameters of regional surface topography evaluation and extract the characteristic parameters related to running-in wear characteristics.Based on the characteristic analysis of the parameters of regional surface topography evaluation, an effective method for extracting the feature parameters set of running-in wear prediction model is proposed.
An effective modeling method based on least squares support vector machine (LS-SVM) is proposed to establish a prediction model of running-in wear characteristics including surface topography and wear loss. Considering that the analytical running-in model can not effectively characterize the complexity of running-in process, the running-in process is regarded as a black box process for machine learning to avoid the deviation caused by the simplification of running-in process, and the input variables of running-in process (working condition and surface morphology) and the output variables of running-in process (surface shape) are established. In order to predict the running-in wear characteristics based on the surface morphology of the friction pair, the relationship between the wear morphology and the running-in wear amount was studied.
The experimental results verify the validity and accuracy of the prediction method of running in wear characteristics.
【學(xué)位授予單位】：華中科技大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2013
【分類號】：TH117

【參考文獻(xiàn)】

相關(guān)期刊論文 前4條

1 韓德寶,關(guān)德林;船舶主機(jī)汽缸套—活塞環(huán)磨合過程的模擬試驗(yàn)[J];大連海事大學(xué)學(xué)報(bào);2004年04期

2 張移山,孔憲梅,陳大融;磨合過程的摩擦學(xué)設(shè)計(jì)研究[J];清華大學(xué)學(xué)報(bào)(自然科學(xué)版);1998年04期

3 楊練根,謝鐵邦,蔣向前,李柱;表面形貌的Motif評定方法及其發(fā)展[J];中國機(jī)械工程;2002年21期

4 葛世榮,陳國安;磨合表面形貌變化的特征粗糙度參數(shù)表征[J];中國礦業(yè)大學(xué)學(xué)報(bào);1999年03期

相關(guān)博士學(xué)位論文 前1條

1 汪選國;銷盤滑動磨損試驗(yàn)的仿真方法研究[D];武漢理工大學(xué);2009年

，

本文編號：2190626