The Subsurface Crack Under Conditions of Slip and Stick Caused by a Surface Normal Force

A solution is given for the elastic stress field in a half plane containing a plane crack parallel to the surface and subjected to a uniform normal pressure and a concentrated normal load. Frictional slip according to Coulomb's law is permitted between the crack faces. As the load is increased, a slip zone originates and grows either from a crack tip or from an intermediate point. Various arrangements of slip and stick zones can occur depending on the magnitude of the load and its location relative to the crack. At very high loads, the crack faces start to separate, but this case is not treated in the present paper.