坡面道路上地面形貌对人体步进摩擦的影响

Effect of Floor Surface Topography on Human Stepping Tribology in Slope Walkway

人体行走经常发生滑摔事故,而坡面道路是人体行走的典型路况之一.当前通过改变鞋底和地板的材料、鞋底和地板的表面形貌以提高步进摩擦系数的研究多是基于水平路面,对坡面道路上的人体行走,特别是地面形貌变化对坡面道路上的人体行走研究较少.本文中以45钢作为材料,制备出表面波纹度相同而表面形貌不同的地板,利用步进摩擦试验平台改变行走路面的坡度研究了地面形貌变化对坡面道路上人体步进摩擦的影响.结果表明:坡度对有效摩擦系数的影响高于表面形貌;随着坡度的增加,安全行走所需的必要摩擦系数增大,地面提供的有效摩擦系数减小,步频则先增大后减小;上坡启动时脚掌与路面的有效接触面积和下坡制动时脚跟的有效接触面积随坡度的增加而减小,导致有效摩擦系数降低,滑摔倾向增大.人体行走姿态为了保持平衡而缩短步长以降低必要摩擦系数.

Slips and falls usually happen during human walking,and slope is a typical walkway.There are many researches about the improving of stepping friction coefficient through changing the materials and surface morphology of sole and floor in level walkway,but only a few are in slope walkway,especially under different surface topography condition.This paper prepared three floors of different surface topography with same surface waviness on 45 steel,studied their stepping friction coefficient in slope walkway by gait friction tester.Results showed that the effect of slope on available coefficient of friction was higher than that of surface roughness.With the increasing of slope,required coefficient of friction increased and available coefficient of friction decreased,and stride frequency first increased then decreased.The effective area that forefoot contacted with walkway decreased with the increasing slope during uphill,as well as the heel contacted with walkway during downhill,that reduced the available coefficient of friction and increased the risk of slip and fall.Human gait shorten the step length to reduce required coefficient of friction in order to maintain body balance.