TORSIONAL IMPACT OF ELASTIC SPHERES

 Juergen Jaeger, Blattwiesenstr. 7, D-76227 Karlsruhe, Germany

Archive of Applied Mechanics, Vol. 64, no. 4, 235-248

email: j_jaeger@t-online.de

Abstract:  In this article, the collison of two geometrically and materially similar elastic spheres, which are rotating around the common normal of their contact area, is analysed. The solution of the static problem, when the spheres are pressed together by a constant normal force and are then subjected to a monotonously increasing torsional couple about the contact normal, has been found by Lubkin. Superposition of such Lubkin solutions for different contact areas  yields the general contact law for finite sequences of normal and torsional displacement increments. The torsional rotation at the end of impact is obtained from numerical integration of the angular equation of motion and the contact law. The Nassi-Shneiderman diagrams of the contact algorithm and the impact algorithm are presented. Some results are plotted and compared with an asymptotic theory for complete adhesion and complete sliding in the contact area.