  This paper is concerned with the minimisation of peak stresses occurring in
linear elasticity. We propose to minimise the maximal von Mises stress of the
elastic body. This leads to a nonsmooth shape functional. We derive the shape
derivative and associate it with the Clarke sub-differential. Using a steepest
descent algorithm we present numerical simulations. We compare our results to
the usual $p$-norm regularisation and show that our algorithm performs better
in the presented tests.
