抄録
It has become clear that the damage on the contact surface is much affected by the tangential force. However, it seems that its influence over the wide range of contact conditions still remains quantitatively indefinite. In this study, some experiments were performed under various unlubricated contact conditions of a hard metal sphere against a hard metal surface subjected to the oscillating tangential force with several static normal loads. The occurence of damage (especially cracking) on the surface in the contact field without any macro slip has been observed. The effects of the normal load and the range of the oscillating tangential force on the occurence of surface cracking and its advance have been investigated. It was also found that these effects can be explained using stress field.
