Bulk-stress effects in double contacts of similar elastic materials

The effects of a remote applied stress on double contacts of similar elastic materials are examined using a numerical method based on Cauchy singular integral equations (SIE). In contrast to single contacts, the space of possible shear configurations is very rich. In many cases, the partial slip problem does not have a contact equivalent. An equation based on displacement continuity is derived to relate the stick-zone extents for any shear configuration; this equation is essential for the solution of general partial slip problems involving two stick-zones. A shear configuration map that shows the types of partial slip solution that occur for various shear load-remote bulk-stress combinations is obtained for biquadratic indenters. Lastly, it is shown that it is possible to predict the shear configuration in some cases for double cylindrical indenters.