BE analysis of delaminated Composite Structures repaired with Piezoelectric Active patches

The main target of the present paper is the analysis of the fracture mechanics behavior of delaminated composite structures actively repaired through piezoelectric patches. The aim at issue has been achieved by using a boundary element code implemented to study piezoelectric solids, including, as limiting case, the applicability to linear elastic anisotropic materials. The assembled structures, made up of the damaged composite components and the piezoelectric patches, have been modelled through the multidomain technique. To take into account for the adhesive layer among the host structure and the active patch, an interface spring-model has been also implemented. The multidomain technique coupled with the spring-model has also allowed the modelling of delamination cracks. The fracture mechanics behavior of bimaterial cracks has been characterized in terms of the total Energy Release Rate (ERR) and the phase angle Ψ, which provide information about the mix between mode I and II of fracture. The numerical results obtained have provided useful information on the design of piezoelectric devices used in the field of the active-repair technology.