本文關鍵詞： 摩擦磨損 微動磨損 扭動微動 力學行為 數(shù)值模擬　出處：《西南交通大學》2013年博士論文　論文類型：學位論文

【摘要】：扭動微動作為一種基本相對運動和變形方式,大量存在于實際工況中,如交通工具中大量存在的球窩配合件及旋轉(zhuǎn)緊固件、輪軸配合、人體關節(jié)、及各種人工關節(jié)等。其產(chǎn)生的磨損損傷會引發(fā)機械零部件服役安全及人體生命健康問題。但扭動微動研究起步較晚,報道較少,解析解存在一定局限性。西南交通大學摩擦學研究所開展的系統(tǒng)試驗研究,主要在二類微動圖基礎上,建立了扭動微動磨損的運行和損傷機理,但扭動微動的力學行為和機理卻有待分析與研究。同時,減緩微動損傷措施的研究主要集中于切向微動,表面工程技術在抗扭動微動損傷中的應用研究極為少見。因此開展扭動微動磨損和防護的力學行為分析,不僅可以深化扭動微動磨損損傷機理、豐富微動摩擦學理論,而且對實際應用中抗扭動微動磨損失效具有重要的工程指導意義。 本研究基于接觸問題有限元方法對扭動微動開展數(shù)值分析,研究關鍵微動參數(shù)對接觸表面及次表面的應力應變分布的影響。從力學角度分析扭動微動磨損損傷特性,并將力學行為和實驗現(xiàn)象進行對比分析；并利用ABAQUS用戶子程序Fric引入接觸表面隨時間和空間各項同性變化的摩擦系數(shù),對扭動微動磨損進行數(shù)值模擬。在摩擦扭矩曲線和試驗結(jié)果較好吻合基礎上,進一步分析扭動微動力學行為；同時開展MoS2涂層扭動微動有限元分析,通過與基體力學行為的比較,探討固體潤滑涂層在抗扭動微動磨損中應用的可行性。獲得的主要結(jié)論如下： (1)扭動微動有限元分析結(jié)果顯示：不同運行區(qū)域扭矩曲線形狀與試驗結(jié)果較好吻合,說明有限元分析中接觸表面的變形行為和摩擦行為與實際基本相符。在有限元分析中,需依據(jù)T-θ曲線形狀結(jié)合接觸狀態(tài)轉(zhuǎn)變特征分析來劃分運行區(qū)域。橢圓型T-θ曲線,并且接觸狀態(tài)云圖中粘著區(qū)隨循環(huán)周次增加有減小趨勢,表明微動運行于混合區(qū)。 (2)數(shù)值模擬結(jié)果的三種微動運行區(qū)域下摩擦扭矩—角位移幅值曲線與試驗結(jié)果無論在形狀還是數(shù)值上均較好吻合,說明所采用摩擦系數(shù)模型能夠模擬扭動微動接觸界面摩擦系數(shù)演化及變形行為,在扭動微動磨損力學機理分析中考慮摩擦系數(shù)的動態(tài)變化非常有必要。在此基礎上,扭動微動的力學行為分析和損傷機理揭示更加可靠。 (3)表面塑性變形和摩擦剪力對表面磨損起主控作用。三種扭動微動運行區(qū)域塑性應變和摩擦剪應力的分布和演化不同,相應的磨損損傷程度和演化也不同。 (4)結(jié)合SWT參數(shù)和關鍵平面方法,對混合滑移區(qū)接觸副表面的裂紋萌生與擴展位置進行預測分析。結(jié)果表明：次表面應力應變分布狀態(tài)決定了裂紋萌生與擴展,裂紋應在粘滑交界處和滑移區(qū)內(nèi)接近接觸邊緣處萌生與擴展,預測結(jié)果與試驗結(jié)果較好吻合。 (5)與LZ50鋼相比,MoS2涂層的運行區(qū)域沒有混合區(qū),其滑移區(qū)向小角位移幅值和高法向載荷方向移動,說明通過微動運行區(qū)域的改變消除了混合區(qū)的損傷；MoS2涂層表面呈現(xiàn)的低摩擦使其與基體相比極易進入滑移區(qū),表面相對運動幅度較大,但摩擦扭矩值卻處于較低水平,表面摩擦剪力始終較小,故由摩擦磨損產(chǎn)生的表面損傷比基體材料輕微。
[Abstract]:Torsionalfretting as a basic relative motion and deformation mode, exists in the actual condition, such as the existence of a large number of vehicles with a ball and a rotating shaft with fasteners, body joints, and various artificial joints. The wear damage can cause mechanical spare parts service life safety and human health problems. But the torsional fretting of a late start, few reports, analytical solutions of some certain limitations. Experimental study of Tribology Research Institute of Southwest Jiao Tong University carried out, mainly in two kinds of fretting maps based on a micro operation and damage mechanism of torsional wear, mechanical behavior and mechanism of torsional fretting but remains to be studied. At the same time. Study on mitigation measures focused on the fretting damage of tangential fretting, surface engineering technology in the application of torsional fretting damage in extremely rare. Therefore the development of micro twist The analysis of mechanical behavior of dynamic wear and protection can not only deepen the torsional fretting wear damage mechanism, but also enrich the fretting tribology theory. It also has important engineering guiding significance for the practical application of torsional fretting wear failure.
In this study, the finite element method of torsional fretting contact problems based on the development of numerical analysis, the key parameters of fretting contact surface and sub surface stress and strain distribution effect. From the point of view of mechanics analysis of torsional fretting wear damage characteristics, and contrasts the mechanical behavior and phenomena; the friction coefficient and the ABAQUS user subroutine Fric change time and space into isotropic contact surface, numerical simulation of torsional fretting wear. In good agreement with the curves of friction torque and the test results on the basis of further analysis of torsional fretting mechanical behavior; at the same time to carry out MoS2 coating torsionalfretting finite element analysis, by comparing with the mechanical behavior of the matrix, to investigate the feasibility of solid lubrication coatings on resisting torsional fretting wear in the application. The main results are as follows:
(1) torsionalfretting finite element analysis results of different operation area of torque curve shape and test agree well, indicating the contact deformation and friction behavior of the surface are basically consistent with the practice of finite element analysis. The finite element analysis, according to the T- curve of contact node theta state transition characteristics to divide operation area elliptic curve T-. Theta, and contact state image sticking zone with cycles decreases with increasing trend, showed that the fretting running on the hybrid zone.
(2) three fretting region of numerical simulation results of the friction torque and angular displacement amplitude curves and experimental results in terms of shape or values are in good agreement, which show that the model can simulate the torsional fretting friction coefficient of contact friction coefficient evolution and deformation behavior, the torsional fretting wear mechanism is considered in the analysis of dynamic change the friction coefficient is very necessary. Based on the analysis of mechanical behavior and damage mechanism of torsional fretting reveals more reliable.
(3) surface plastic deformation and friction shear force play a major role in surface wear. The distribution and evolution of plastic strain and frictional shear stress in three kinds of fretting operation region are different, and the corresponding wear damage degree and evolution are also different.
(4) combined with the SWT parameters and the critical plane method, the crack on the surface of the hybrid slip zone contact initiation and propagation position were predicted and analyzed. The results show that the surface stress and strain distribution determines the initiation and propagation of crack, crack in the stick slip and slip zone near the junction of the inner edge of the contact initiation and propagation. The prediction results and the test results are in good agreement.
(5) compared with LZ50 steel, the operating range of MoS2 coating without mixing zone, the slip zone to the small angular displacement amplitude and normal load direction, the mixed zone damage is eliminated by the fretting regime change; the low friction surface of MoS2 coating showed the compared with the matrix easily enter the slip zone the surface, the relative motion greatly, but the friction torque value is at a low level, the surface friction shear was always small, so the friction and wear surface damage of the matrix material produced slightly.

【學位授予單位】：西南交通大學
【學位級別】：博士
【學位授予年份】：2013
【分類號】：TH117

【參考文獻】

相關期刊論文 前10條

1 王運動;羅軍;莫繼良;劉家浚;朱e，

本文編號：1525487