The contact problem for a shallow shell containing a vertical crack is
considered. The solution of the problem satisfies two inequality rest
rictions describing the mutual non-interpenetration of the shell and a
punch, and the condition of non-interpenetration for the crack faces.
The purpose of this paper is to investigate a control problem using e
xternal loading with an objective functional describing the crack open
ing. The regularity of the solution is investigated near the tips of t
he crack. In particular, for a crack with zero opening the solution is
shown to below to the class C-infinity. The convergence of the soluti
ons of the optimal control problems when the parameters are perturbed
is analysed.