Tadayoshi Koizumi

A study of the relationships governing starting rolling friction

Abstract In this study the behaviour of the small displacement of starting rolling friction in the rolling contact between a flat surface and rollers is investigated and a rolling friction force-displacement relationship in the region of the starting rolling displacement is proposed by using the fact that the area of the hysteresis loop increases linearly with the nth power of the rolling friction. Furthermore, the behaviour of the hysteresis loop at the rolling contact surface has been investigated experimentally and theoretically. It was found that the area of the hysteresis loop increases linearly with the second power of the rolling distance in the region of a starting rolling displacement.

The damping capacity of a flat surface to roller contact

Abstract The behaviour of the damping capacity of a flat surface to roller contact with various beam hardnesses and thicknesses was investigated. It was established that the hardness and thickness of the beam have a marked effect on the characteristics of its damped vibrations. The logarithmic damping decrement increases proportionately with the real area of contact Ar = Q/Hv until the preload reaches a value at which plastic deformation of the contact surfaces commences and the value of the logarithmic damping decrement is a maximum.

Study on Bending Strength of Cantilever Beam Formed by Map Functions.

The bending strength of cantilever beam, which is formed by map function, has been investigated. The map function contains a parameter m and p which are able to change a shape of a curve, and its shape is symmetrical in the case of m=3. From the calculated results of stress, it has been found that the stress of cantilever beam formed by the map function of m=3 and m=1.5 shows the uniform strength, and the stress of beam of m=2 shows the minimum value. Though the A1 bifurcation splits firstly in the case of m=2, the bifurcation of A1 and the stress of cantilever beam are influenced by the shapes of a map function.