樹脂フォーム/ゴム積層材料の摩擦挙動の解明と耐滑スポーツシューズへの応用に関する研究

要約のみTohoku University堀切川一男課

Precise Measurement of Clearance between Two Substrates Using Evanescent Waves

In the material designing process of footwear outer-soles, the rubber grip property under lubricated conditions is important. Generally, friction behaviors of rubber under such conditions are influenced by contact states, which can be changed by various factors, i.e. viscosity, sliding velocity, normal force, surface roughness and wettability between two substrates. To discuss the influences of each parameter, the contact conditions are investigated. The purpose of this study is to establish a new method to measure the distributions of real contact area and film thickness between two substrates based on the decay behavior of an evanescent field in a total reflection method. In conclusion, film thickness was measured with an accuracy of 1 nm in a range of clearance of less than 800 nm

Influence of Dewettability on Rubber Friction Properties with Different Surface Roughness under Water/Ethanol/Glycerol Lubricated Conditions

In the material designing process of footwear outer-soles, a grip property of rubber is of crucial importance under water or oil lubricated condition. In general, contact states between rubber and floors under lubricated conditions are influenced by various factors, i. e. viscosity of a lubricant, sliding velocity, normal force, surface roughness and wettability between the two substrates. It has been said that lubrication conditions can be distinguished based on Stribeck curves, which are described by the relationship between Sommerfeld numbers and dynamic friction coefficients. Wettability under the static condition is estimated by the spreading coefficient, which is used to evaluate the energy balance of interface free energies at a triple line. The purpose of this study is to investigate influences of surface free energies, viscosities, sliding velocities and surface roughnesses on dynamic friction coefficients of rubber under lubricated conditions. The influences of spreading coefficients on the behaviors of Stribeck curves and the relationship between dewetting velocities and dynamic friction coefficients are also discussed

Abrasion wear analysis in running shoes using a gridded methodology with CIE-L-a-b colour identification

Wear identification and projection have eluded shoe manufacturers due to the myriad of factors that affect the abrasion wear of shoes. Using a gridded three-dimensional cloud comparison in CloudCompare software, abrasion wear thickness of shoes was identified using the CIE-L-a-b colour system that is interpolated with the physical formula representation of colours. After obtaining the thickness lost, other wear factors like the material properties of the shoe sole, the runners’ personal profile and the running schedule were combined for wear projection. The methodological process from a non-destructive wear detection to wear projection allows shoe manufacturers to reduce the iterations of wear testing while maximizing the entire analysis of shoe wear. Shoe samples were kindly sponsored by ASICS Institute of Sport Science