From Damage to Delamination in Nonlinearly Elastic Materials at Small Strains

Brittle Griffith-type delamination of compounds is deduced by means of I-convergence from partial, isotropic damage of three-specimen-sandwich-structures by flattening the middle component to the thickness 0. The models used here allow for nonlinearly elastic materials at small strains and consider the processes to be unidirectional and rate-independent. The limit passage is performed via a double limit: first, we gain a delamination model involving the gradient of the delamination variable, which is essential to overcome the lack of a uniform coercivity arising from the passage from partial damage to delamination. Second, the delamination gradient is suppressed. Noninterpenetration- and transmission-conditions along the interface are obtained.