Understanding the mechanism of acoustic emission generation due to surface asperity interaction in mixed lubrication conditions

了解混合润滑条件下由于表面粗糙相互作用而产生声发射的机制

• 批准号: EP/L021757/1
• 负责人: Alastair Clarke
• 金额: $ 12.54万
• 依托单位: CARDIFF UNIVERSITY
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2014
• 资助国家: 英国
• 起止时间: 2014 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FL021757%2F1
• 关键词: Understanding; mechanism; acoustic; emission; generation

When they mesh together, gear teeth are placed under very high loads and separated by thin films of lubricant often only a few microns thick. High temperatures and pressures develop within the oil film between the gear teeth. Real gears, particularly in aerospace transmissions, may have finely machined surfaces and appear smooth but on the microscopic scale of the lubricant film they are rough. The peaks of these rough surfaces (known as asperities) often come into contact with each other. These conditions can lead to failure of the lubricant film itself, wear, surface damage and gradual cracking (fatigue), none of which are desirable in an aircraft engine for example!When a material undergoes deformation (such as occurs when rough surfaces come into loaded contact) a rapid release of energy in the form of transient elastic waves occurs, known as Acoustic Emission (AE). These waves can be recorded using sensors mounted on the material, and AE methods have been widely used in monitoring structures where they have been shown to out-perform other methods. In gear systems, asperity contact, wear, surface damage or cracking causes acoustic emissions to occur. This project focusses on the development of an advanced computational model to predict the levels of AE generation due to asperity interaction within a lubricated contact, such as those found between gear teeth. This asperity interaction has been found by previous researchers to be a significant part of the AE signal from a pair of meshing gears. The work will form a key part of a long-term aim of developing the use of AE monitoring techniques for high speed, heavily loaded power transmission gearing.The work will include both the development of the computational models, which are based on strain energy calculations and advanced simulations of pressures and shear stresses within the lubricant film, together with a comprehensive experimental programme.

当它们啮合在一起时，齿轮齿被置于非常高的载荷下，并被通常只有几微米厚的润滑剂薄膜隔开。齿轮齿之间的油膜内会产生高温和高压。真实的齿轮，特别是在航空航天传输中，可能具有精细加工的表面并且看起来光滑，但在润滑剂膜的微观尺度上，它们是粗糙的。这些粗糙表面的峰（称为粗糙体）经常彼此接触。这些条件会导致润滑油膜本身失效、磨损、表面损伤和逐渐开裂（疲劳），这些都不是航空发动机所希望的。当材料发生变形时（例如当粗糙表面进入负载接触时发生），会发生瞬态弹性波形式的能量快速释放，称为声发射（AE）。这些波可以使用安装在材料上的传感器记录，AE方法已被广泛用于监测结构，其中它们已被证明优于其他方法。在齿轮系统中，粗糙接触、磨损、表面损伤或裂纹会导致声发射的发生。该项目的重点是开发一种先进的计算模型，以预测由于润滑接触内的粗糙相互作用而产生的AE水平，例如在齿轮齿之间发现的AE。先前的研究人员已经发现，这种粗糙的相互作用是一对啮合齿轮的AE信号的重要组成部分。这项工作将成为开发高速重载动力传动齿轮AE监测技术的长期目标的关键部分。这项工作将包括开发基于应变能计算的计算模型和润滑油膜内压力和剪切应力的高级模拟，以及全面的实验计划。

项目成果

Gear tooth root fatigue test monitoring with continuous acoustic emission: Advanced signal processing techniques for detection of incipient failure

• DOI: 10.1177/1475921717700567
• 发表时间: 2018-05
• 期刊: Structural Health Monitoring
• 作者: D. Crivelli;J. McCrory;S. Miccoli;R. Pullin;A. Clarke

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.

Use of high frequency analysis of acoustic emission signals to determine rolling element bearing condition

使用声发射信号的高频分析来确定滚动元件轴承状况

• DOI: 10.1088/1742-6596/628/1/012074
• 发表时间: 2015
• 期刊: Conference Series
• 作者: Cockerill A

Generation of Acoustic Emission from the running-in and subsequent micropitting of a mixed-elastohydrodynamic contact

• DOI: 10.1016/j.triboint.2017.11.011
• 发表时间: 2018-03
• 期刊: Tribology International
• 影响因子: 6.2
• 作者: Simon Hutt;A. Clarke;H. P. Evans

Determination of rolling element bearing condition via acoustic emission

• DOI: 10.1177/1350650116638612
• 发表时间: 2016-11-01
• 期刊: PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
• 影响因子: 2
• 作者: Cockerill, A.;Clarke, A.;Holford, K. M.
• 通讯作者: Holford, K. M.