rails fracture by the growth of fatigue crack or critical crack is one of the prevalent defects in railway. the rail fracture, failure and stress analysis should be studied in order to prevention of rail fracture. in this paper, new formulation of contact stress for two rolling bodies is presented, where the results are closed to the hertz stress formulation. moreover, stress analysis is done b...

Helical bevel gears have inclined or twisted teeth on a conical surface and the common types are skew, spiral, zerol, hypoid gears. However, this study does not include Due to geometric complexities of gears, commonly used methods in their design based concept equivalent virtual spur gear. The approach paper is following assumptions, a) helix angle helical equal mean spiral angle, b) pitch diam...

BACKGROUND High contact hip stress is believed to be one of the key biomechanical factors involved in the hip cartilage degeneration and osteoarthritis. Accordingly, with increasing age high contact hip stress is expected to cause elimination of subjects from the population of healthy hips, but its predictive value has not been evaluated so far. The objective of the paper is to investigate whet...

Our objectives were to determine cartilage contact stress during walking, stair climbing, and descending stairs in a well-defined group of normal volunteers and to assess variations in contact stress and area among subjects and across loading scenarios. Ten volunteers without history of hip pain or disease with normal lateral center-edge angle and acetabular index were selected. Computed tomogr...

The present study concerns oxygen-ion transfer between yttriastabilized zirconia single crystals (YSZ/YSZ) under mechanical contact stress. Two YSZ single crystal plates were piled up between platinum meshes, and contact stress was mechanically applied. The interfacial conductivity as well as the bulk conductivity was successfully measured with this setup. The interfacial conductivity is greatl...

This paper investigates the effect of electrical contact on the thermal contactstress of a microrelay switch. A three-dimensional elastic-plastic finite element model withcontact elements is used to simulate the contact behavior between the microcantilever beamand the electrode. A model with thermal-electrical coupling and thermal-stress coupling isused in the finite element analysis. The effec...