  The quasistatic rate-independent evolution of a delamination at small strains
in the so-called mixed mode, i.e.~distinguishing opening (Mode I) from shearing
(Mode II) is rigorously analyzed in the context of a concept of stress-driven
local solutions. The model has separately convex stored energy and is
associative, namely the 1-homogeneous potential of dissipative force driving
the delamination depends only on rates of internal parameters. An efficient
fractional-step-type semi-implicit discretisation in time is shown to converge
to specific, stress-driven like) local solutions that may approximately obey
the maximum-dissipation principle. Making still a spatial discretisation, this
convergence as well as relevancy of such solution concept are demonstrated on a
nontrivial 2-dimensional example.
