On Debonding and Delamination Effects in Adhesively Bonded Cracks on Fractal Type

The present paper studies the influence of adhesives on the behaviour of cracks in deformable bodies. Especially the delamination and debonding effects are studied. The adhesive material is assumed to introduce nonmonotone possibly multivalued laws which can be described via nonconvex superpotentials. Cracks of fractal geometry are considered. Approximating the fractal crack 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 complementary energy for each approximation of the fractal crack, we get the solution of the problem. Numerical examples, using singular elements for the consideration of the crack singularity, illustrate the theory. This revised version was published online in August 2006 with corrections to the Cover Date.