  We study the interior and exterior contact problems for hemitropic elastic
solids. We treat the cases when the friction effects, described by Tresca
friction (given friction model), are taken into consideration either on some
part of the boundary of the body or on the whole boundary. We equivalently
reduce these problems to a boundary variational inequality with the help of the
Steklov-Poincar'e type operator. Based on our boundary variational inequality
approach we prove existence and uniqueness theorems for weak solutions. We
prove that the solutions continuously depend on the data of the original
problem and on the friction coefficient. For the interior problem necessary and
sufficient conditions of solvability are established when friction is taken
into consideration on the whole boundary.
