INCREASE OF FRICTIONAL FORCE OF RUBBER BLOCK BY UNIFORM CONTACT PRESSURE DISTRIBUTION AND ITS APPLICATION TO A TIRE

摘要

The relationship of the contact pressure and the friction coefficient of rubber has been studied. Since the pressure is not uniform in the rubber block, the relationship of the pressure distribution and the friction coefficient becomes important. The new theorem, "the friction coefficient is maximized when the pressure distribution is uniform, if μ(P)P is convex with respect to P", was derived. In order to verify this theorem, the surface shape of the rubber block with the uniform pressure distribution is obtained by the optimization technique. The block edge of the optimized surface is rounded. The friction coefficient with the optimized block surface increases 2% at small deformation and 10% at large deformation compared with the block featuring a flat surface. On the other hand, the friction coefficient on ice decreases 30% due to water penetration between block and ice.