Effect Of Surface Morphology Of Materials In Process Of Human Walking On Slip Resistance

Friction between the foot and the ground is closely linked with safety during walking. If the friction force is too small, there will invariably be sideslips, forward-backward slips, or even falls. Slip and fall has attracted widespread attention, for it not only has done damage to people financially and mentally, but also causes losses to the society in terms of social stability.The study of step friction focuses on the characteristics of people walking, as well as the basic rules of intermitted interactions between the ground and the people with those walking characteristics during walking. Stepping friction has a wide-ranging applied background, involving medicine, decoration and footwear etc. At present, step friction mainly studies the impact of sole material and surface condition, pavement materials, surface state and other factors on the non-slip property.Using the BM-II slip meter, this article looks at the influence of sole materials, floor materials, the ground state and surface morphology on friction coefficient. It also explores the effect of surface morphology of materials on slip resistance during walking by using the Stepping Friction Test Bed which is self-developed by the Key Laboratory for Material Tribology of HUST(Henan University of Science and Technology). Finally, the article ends in comparing and analyzing the two kinds of non-slip property testing systems.Under the definite circumstances, the test made by the BM-ⅡNon-slip Tester has shown that the frictional coefficient of rubber is the greatest and non-slip property of cement pavement is the best; the frictional coefficient in dry condition is bigger than that in the lubricant state; the friction coefficient is close to zero in the state of oil; test conditions and material characteristics both impose impact on friction coefficient, while the influence of the former is more prominent; and in a range of certain distance, the space between patterns is directly proportional to the friction coefficient.It is tested by the Stepping Friction Test Bed that the surface roughness and surface pattern have the same effect on non-slip property during walking. The greater the surface roughness and pattern spacing, the smaller the frictional coefficient and in turn the less likely people are to fall. The effect of sample orientation on the non-slip property is obvious, with the non-slip property in vertical test better than that in horizontal test.The agreement in the result of non-slip property test between BM-Ⅱ non-slip testing machine and stepping friction test machine has shown that none could exist effectively without each other. As a tool of screening, BM-Ⅱ should be used to screen materials with better non-slip property so that simulation test of dynamic non-slip property could be carried out in the stepping friction testing machine.