On debonding and delamination effects in adhesively bonded cracks on fractal type

The present paper studies the influence of adhesives on the behaviour of cr acks in deformable bodies. Especially the delamination and debonding effect s are studied. The adhesive material is assumed to introduce nonmonotone po ssibly multivalued laws which can be described via nonconvex superpotential s. Cracks of fractal geometry are considered. Approximating the fractal cra ck by a sequence of smooth surfaces or curves and combining this procedure with an algorithm based on the optimization of the potential and of the com plementary energy for each approximation of the fractal crack, we get the s olution of the problem. Numerical examples, using singular elements for the consideration of the crack singularity, illustrate the theory.