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 associ! ated 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 _nite element implementation are discussed together with a local control algorithm for the treatment of unstable paths[ Numerical examples showing the e}ect of interaction between geometrical and material nonlinearities are presented