Recommended by Radu P.VOINEA, member of the Romanian Academy PIVOT FRICTION IN PLANAR MOTIONS

This paper presents an anallysis of a frictional planar rigid-body motion. Friction occurs on the contact area between the rigid body and the bearing horizontal plane producing a resultant friction force and a pivot friction moment. The general solution depends on four distinct integrals. In the case of a circular contour only two integrals remain which result in closed forms. Their evaluation is made through an integral representation for the reciprocal distance between two points. The solution of the planar circular disk motion with friction is checked against known results on particular motions. Key words: planar motion, friction force, pivot friction moment, elliptical integrals 1