Department of Bioengineering, University of Pittsburgh, Benedum Engineering Hall #302, 3700 O'Hara St., Pittsburgh, PA, 15261, United States.
Crossroads Consulting, LLC, 1334 Luzerne St Ext, Johnstown, PA, 15905, United States; Mechanical Engineering, University of Pittsburgh Johnstown, Johnstown, PA, 15905, United States.
Appl Ergon. 2020 Jan;82:102959. doi: 10.1016/j.apergo.2019.102959. Epub 2019 Sep 27.
Available coefficient of friction (ACOF) is a common metric of footwear traction performance. ACOF is the ratio of friction to normal force, often averaged over a time-interval. The time-interval needed to achieve repeatable and valid ACOF is unknown. A post-hoc analysis was performed on nine shoe-floor-contaminant combinations to assess the repeatability and bias of data averaged across 4 time-intervals (2 ms, 50 ms, 100 ms, 200 ms) after the target normal force was reached. The ability to predict human slips was assessed for ACOF across these intervals. Differences in repeatability and validity across the four intervals were small. However, statistically significant differences were observed for the shortest compared with the longest interval (lower repeatability yet modestly improved predictive ability). Given the limited impact of time-interval on the results, a shorter interval of 50 ms is recommended to enable testing of smaller floor samples.
可用摩擦系数（ACOF）是一种常用的鞋类牵引力性能指标。ACOF 是摩擦力与法向力的比值，通常在一段时间内平均计算。达到可重复且有效的 ACOF 所需的时间间隔是未知的。对九种鞋-地板-污染物组合进行了事后分析，以评估在达到目标法向力后 4 个时间间隔（2ms、50ms、100ms、200ms）内平均数据的重复性和偏差。评估了 ACOF 在这些间隔内预测人类滑倒的能力。四个间隔内的重复性和有效性差异较小。然而，与最长间隔相比，最短间隔观察到统计学上显著差异（重复性较低，但预测能力略有提高）。考虑到时间间隔对结果的影响有限，建议使用较短的 50ms 间隔，以能够测试更小的地板样本。
