宏观摩擦仪器引起不确定度的分析处理

Analytical treatment of uncertainties for a macroscopic tribology instrumentation

在摩擦学中,摩擦系数与磨损率都是通过实验得到的,本文的工作旨在研究与这两个参数估算相关的测量不确定度。文中特别采用了一个标准的销-盘摩擦计,其上的两个销固定在同一端面。针对不同的负载、滑动距离和测试时间,总共进行了20次测试,测试时环境温度和相对湿度需保持恒定,测试后使用触针式轮廓仪来获得磁盘截面的磨损疤痕剖面,通过测量磨损痕迹截面及平均磨损体积得到磨损率。实验结果表明,载荷测量时的不确定度对摩擦系数和磨损率的评估有很大的影响,所获得的信息对于优化实验装置和/或开发适当的程序以降低测量不确定度是十分有用的。

In tribology, friction coefficient and wear rate are usually determined experimentally. The present work is aimed at investigating the measuring uncertainties associated with the evaluation of these two parameters. In particular, a standard pin-on-disk tribometer, having two pins constrained to a counterface, has been used. Varying normal load, sliding distance and test duration, a total of twenty tests have been carried out. Environmental temperature and relative humidity have been main- tained constant. After the tests, a stylus profilometer has been used to acquire the wear scar profiles on the cross-sections of the disks. The wear rates have been subsequently calculated by measuring the area of the wear track cross-sections and evaluating an average wear volume. The experimental results show that the load measurement uncertainty strongly affects the evaluation of both friction coefficient and wear rate. The information obtained are useful to optimise the experimental apparatus and/or to develop suitable procedures aimed at reducing measurement uncertainties.