A general two-dimensional solution has been obtained analytically for the c
rack with interating rough faces. The interaction has been modelled at a la
rge scale as (1) Mohr-Coulomb friction and (2) the crack opening being a kn
own function of sliding. The detailed consideration of a crack with saw-lik
e faces has shown that the energy release rate is less than for a conventio
nal shear crack. Tensile stress concentration caused by the crack opening r
educes the angle of kinking though not sufficiently to make the crack propa
gate in its own plane. At a certain magnitude of shear loading the opening
reaches its maximum value determined by the height of asperities. Starting
from this point the zone where the maximum opening is reached rapidly incre
ases and the dependencies of crack face displacements and the area of crack
opening on the load become nonlinear. This however does not affect values
of the stress intensity factors.