Wheel-rail wear simulation

This paper declares the method for the computation of the wheel-rail surface degradation in a curve where the major surface degradation phenomenon is a combination of wear and plastic deformation. Simulating the form change of the wheel-rail contacts help to identify the risk of severe or catastrophic wear resulting from increased train speeds and axle loads and can help in determining more efficient maintenance schedules for track and rolling stock. The method was previously used to simulate the form change in a two-roller contact. The progress is made in the terms of general geometry modelling, which makes differences in the various contact configurations. The normal contact problem is analysed using the modified Winkler method and calibrated using the results from FEM modelling of the wheel-rail contact with elastic-plastic material model. A piecewise approach and stick-slip analysis of the rolling-sliding contact solves the tangential problem. A linear wear law is used in the wear computation. The form change for a typical two-point contact in a low radius curve was analysed and discussed.     

Sliding wear evaluation of hot isostatically pressed (HIPed) thermal spray cermet coatings

The aim of this study was to investigate the potential of applying hot isostatic pressing (HIPing) as a post-treatment to thermally sprayed wear resistant cermet coatings. The relative performance of the as-sprayed and hot isostatically pressed functionally graded WC-NiCrBSi coatings was investigated in sliding wear conditions. Coatings were deposited using a high velocity oxy-fuel (HVOF)—JP-5000 system, and HIPed without any encapsulation at temperatures of 850 and 1200 °C. The influence of post-treatment temperature on the coating's wear resistance was thus investigated. Sliding wear tests were carried out using a high frequency reciprocating ball on plate rig using steel and ceramic balls under two different loads. Results are discussed in terms of microstructural investigations, phase transformations, mechanical properties, and residual stress investigations. The results indicated significant alteration of the coating microstructure, brought about by the coating post-treatment, particularly when carried out at the higher temperature of 1200 °C. As a consequence, developments in the coating mechanical properties took place that led to higher wear resistance of the HIPed coatings.     

Experimental study of wear interaction between piston ring and piston groove in a radial piston hydraulic motor

The wear interaction between piston ring and piston groove in a radial piston hydraulic motor was studied in regard to mass loss and changes in form and surface roughness. A specially developed test rig that simulates the tilting movements of pistons at the end of strokes was used in the test. The results show that wear on the piston ring groove can be up to 10 times greater than the wear on the piston ring. For both interacting surfaces, the dominant wear mechanism was mild wear. The results from a factorial design show that the form of the piston groove significantly influences the amount of wear.     

航空发动机磨损在线监测的能谱数据处理方法研究

对用于航空发动机磨损在线监测的能谱数据处理方法进行了研究。介绍了基于同位素Ｘ射线荧光法的滑油磨损在线监测系统的组成及工作原理,通过对所获得能谱数据进行平滑、剥谱、寻峰、峰净面积计算、浓度插值计算等处理,就可以实现杂质浓度的自动检测。文中担子一种函数拟合寻峰方法,实现结果表明,这种方法具有算法简单、运算速度快等优点,特别适合于在线监测的能谱数据处理。     

压电双晶片参数及温度特性的动态测试方法

本文提出一种压电材料参数动态测试模型,用于测量压电双晶片的几个主要材料参数：压电应变常数ｄ３１、机电耦合系数ｋ３１、介电常数ε３３＾Ｔ、弹性柔顺系数ｓ１１＾Ｅ及材料参数的温度特性。本文的这种测量方法不同于通常的由标准试样测量压电材料参数的方法,是直接由一种实用元件－压电双晶片（非标准试样）测量压电材料的参数。文中详细描述了测试原理、测试步骤及一种实际试样的测试结果。理论与实验结果表明：这种新的测试     

奥氏体离子氮碳共渗后钢的耐磨性研究

研究 2 0钢、45钢经奥氏体离子氮碳共渗后的耐磨性和抗咬合性 ,并与普通离子氮碳共渗后的作了比较 ,试验表明 :在 5 70～ 70 0℃范围内进行离子氮碳共渗后 ,其耐磨性和抗咬合性以 6 30℃处理时为最佳 ,6 6 0℃处理时最差 ,而 5 70～ 6 0 0℃处理时则介于两者之间 ,通过适当提高共渗温度 ,再提高渗速 ,从而缩短共渗时间的同时 ,可以提高耐磨损性能。     

有机钼添加剂在成品油和行车试验中的应用

制备了一种含硫、磷、钼的油溶性有机化合物,作为润滑油添加剂,分别将其加入到基础油,６８号汽轮机油和１０Ｗ／３０ＱＤ级汽油机油中,润滑油性能试验表明,可降低油品温升,并与油品中其他功能添加剂有良好的协作作用;行车试验表明,可延长换油期,降低汽车发动机主要摩擦副的零件磨损,大大延长使用寿命。     

凸轮机构磨损数值仿真软件研制

根据零件磨损过程一般数值仿真方法 ,以凸轮机构为研究对象 ,开发出不同类型凸轮磨损仿真软件 ,可实现不同极根条件下的凸轮磨损寿命预测、参数优化和状态监测等功能。     

引起流体动力与润滑系统失效的根源性工况分析

本文对流体动力与润滑系统失效的根源性原因进行了分析 ,提出导致系统失效根源性工况的特征参数的选取方法 ,在此基础上提出系统根源性工况的监测策略。     

刀具磨损状态在线监测技术

通过对切削加工过程中声发射（ＡＥ）信号频域特改正的研究,指出了ＡＥ信号中与刀具磨损状态有关的成分在频域内的分布规律,在此基础上分析了ＡＥ信号的均方根值ＡＥＲＭＳ和振铃计数与刀具后面磨损量ＶＢ之间的对应关系,建立了一种基于ＡＥ信号能量的双阈值判断监测方法。试验表明该方法能很好地解决持定切削条件下刀具磨损的在线监测问题。