Geometrical and interfacial non-linearities in the analysis of delamination in composites

The subject of this paper is the study of interactions between delamination and geometrical nonlinearities. This problem generally addressed by means of Fracture Mechanics, is here treated by modelling interfacial degradation through irreversible, softening interface constitutive laws. Geometrical nonlinearities are associated to large displacements of thin layers which are assumed to be hyperelastic. A general formulation is presented and then specialised to the case of rectilinear laminated beams. Numerical aspects concerning finite element implementation are discussed together with a local control algorithm for the treatment of unstable paths. Numerical examples showing the effect of interaction between geometrical and material nonlinearities are presented. (C) 1999 Elsevier Science Ltd. All rights reserved.