MIXED LUBRICATION, WEAR AND CONTACT FATIGUE OF ROUGH SURFACES

粗糙表面的混合润滑、磨损和接触疲劳

• 批准号: EP/G06024X/1
• 负责人: R W Snidle
• 金额: $ 53.9万
• 依托单位: CARDIFF UNIVERSITY
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2009
• 资助国家: 英国
• 起止时间: 2009 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FG06024X%2F1
• 关键词: MIXED; LUBRICATION; WEAR; CONTACT; FATIGUE

Full-film hydrodynamic lubrication is an ideal which is rarely achieved in practice. In most practical rolling/sliding contacts such as those in gears, bearings and replacement human joints the roughness of the surfaces plays an important part in their lubrication, wear and surface fatigue. In gears, for example, the combined roughness of even the best quality ground surfaces is usually of the order of the oil film which can be generated hydrodynamically. A similar situation occurs in roller bearings at low speed or high temperature and in replacement human joints because of the low effective viscosity of the lubricant. This leads to a lubrication regime which has been loosely described as mixed (meaning a mixture of hydrodynamic and boundary lubrication), or more specifically as micro-elastohydrodynamic lubrication (micro-EHL) in which high ripple pressures occur and colliding asperities on the two surfaces act as individual, transient elastohydrodynamic/solid contact encounters. This project addresses two important engineering consequences of mixed lubrication: (1) mild wear/wear particle generation, and (2) near-surface rolling contact fatigue/micropitting. Much progress has been made in numerical modelling of micro-EHL, but such analyses, if they are to be of practical use, must now be developed to include the detailed behaviour of solid contact events in terms of a wear model. The project will therefore produce an analysis of contact duration, traction, adhesion, flash temperatures and particle removal. The second major development required, in order to advance the study of near-surface distress due to fatigue, is the effect of initial plastic deformation of asperities during the crucial running-in phase when machine surfaces are brought into heavy contact for the first time. This will include a detailed treatment of plastic deformation, permanent set and residual stress field of asperity features.Our specific objectives are to:1. Develop a consistent mixed hydrodynamic/solid contact treatment for real surfaces which includes the detailed modelling of transient dry asperity contacts.2. Develop a model of mild wear particle generation based on the detailed friction, adhesion, deformation and temperatures occurring at transient contacts.3. Produce a model of near-surface fatigue, relevant to the phenomenon of micropitting and rolling contact fatigue, which includes the permanent set and residual stress field obtained from elastic/plastic contact analysis.4. Carry out controlled experiments under realistic engineering load and speed conditions to validate each of these modelling developments.

全膜流体动力润滑是一种在实践中极少实现的理想润滑方式。在大多数实际的滚动/滑动接触中，如齿轮、轴承和人体关节中的滚动/滑动接触，表面的粗糙度对它们的润滑、磨损和表面疲劳起着重要作用。例如，在齿轮中，即使是质量最好的磨削表面的综合粗糙度通常也是可以由流体动力产生的油膜的量级。由于润滑剂的有效粘度低，在低速或高温下的滚子轴承和更换人体关节时也会出现类似的情况。这导致了一种被松散地描述为混合润滑(即流体动力和边界润滑的混合物)的润滑状态，或者更具体地说，被描述为微弹流润滑(Micro-EHL)，其中出现高波纹压力，并且两个表面上的碰撞粗糙处作为单独的、瞬时的弹流/固体接触接触。该项目解决了混合润滑的两个重要工程后果：(1)轻微磨损/磨损颗粒的产生；(2)近表面滚动接触疲劳/微点蚀。在微观弹流润滑的数值模拟方面已经取得了很大的进展，但如果要有实际用途，现在必须发展这种分析，以包括固体接触事件在磨损模型方面的详细行为。因此，该项目将对接触时间、牵引力、附着力、闪光温度和颗粒清除进行分析。为了推进疲劳引起的近表面损伤的研究，需要的第二个主要发展是在关键的磨合阶段，当机器表面第一次进入重度接触时，粗糙度的初始塑性变形的影响。这将包括对粗糙特征的塑性变形、永久设置和残余应力场的详细处理。我们的具体目标是：1.开发用于真实表面的一致的流体动力/固体混合接触处理，其中包括瞬时干式粗糙接触的详细建模。根据瞬时接触时发生的摩擦、粘着、变形和温度，建立轻微磨粒产生的模型。建立了与微点蚀和滚动接触疲劳现象相关的近表面疲劳模型，包括弹塑性接触分析得到的永久变形应力场和残余应力场。在真实的工程负载和速度条件下进行受控实验，以验证这些建模开发的每一个。

项目成果

Elastohydrodynamic contact and fatigue of gear tooth surfaces

齿轮齿面的弹流接触和疲劳

• 作者: H P Evans (Author)

Prediction of microgeometrical influences on micropitting fatigue damage on 32CrMoV13 steel

• DOI: 10.1016/j.triboint.2012.07.018
• 发表时间: 2013-03
• 期刊: Tribology International
• 影响因子: 6.2
• 作者: A. Fabre;H. P. Evans;L. Barrallier;K. Sharif;M. Desvignes

Microgeometrical influences on micropitting fatigue damage: multi-scale analysis

• DOI: 10.1177/1350650110396980
• 发表时间: 2011-06
• 期刊: Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology
• 作者: A. Fabre;L. Barrallier;M. Desvignes;H. P. Evans;M. P. Alanou

Understanding micropitting in gears

• DOI: 10.1177/0954406215606934
• 发表时间: 2016-04-01
• 期刊: PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART C-JOURNAL OF MECHANICAL ENGINEERING SCIENCE
• 影响因子: 2
• 作者: Clarke, A.;Evans, H. P.;Snidle, R. W.
• 通讯作者: Snidle, R. W.

Analysis of Micro-Elastohydrodynamic Lubrication and Prediction of Surface Fatigue Damage in Micropitting Tests on Helical Gears

斜齿轮微点蚀试验中的微弹流润滑分析及表面疲劳损伤预测

• DOI: 10.1115/1.4007693
• 发表时间: 2013
• 期刊: Journal of Tribology
• 作者: Evans H