2020 年 86 巻 888 号 p. 19-00451
This paper describes the result of a tangential force measurement experiment by means of test wheels which is 500mm in diameter in order to investigate the relation between the size of the contact-patch and the tangential force characteristics. In the previous study on the tangential force characteristics of the wheel/rail, it had been sometimes indicated that the experimental results are a little bit smaller than those derived from the Kalker’s theory. Therefore, with a focus on the contact-patch of the wheel/rail, contact-patches of various sizes are set by means of changing the vertical load from 5kN to 35kN, and the tangential force coefficient and creep coefficient of contact-patch of various sizes are evaluated in terms of comparison with the Kalker’s theoretical value under the same criteria. As a result, we confirmed that the creep coefficient is 60% to 90% compared with the theoretical value under the same experimental conditions, because the ambient humidity of the test wheel is high and the contact-patch changes a little due to wear and plastic deformation. On the other hand, it has been clarified that the tangential force coefficient under large slip ratio condition in this study is saturated without falling like the Kalker’ theory.