STABILITY AND ERROR ESTIMATE OF A COHESIVE ZONE MODEL IMPLEMENTED USING THE AUGMENTED LAGRANGIAN METHOD

LABANDA, NICOLAS AGUSTIN; GIUSTI, SEBASTIÁN; LUCCIONI , BIBIANA MARÍA

Buenos Aires

Congreso; PANACM 2015; 2015

AMCA, CIMNE, IACM

Since the origins of the cohesive zone model (CZM) proposed by Dugdale [1] and later by Barenblatt [2], the approach has been increasingly used and studied in computational mechanics community and several traction-separation criteria have been proposed to analyse damage in different kinds of materials. The classical way to implement those CZM is straightforward considering a fracture equilibrium term in the global solid equilibrium equation as an intrinsic behaviour. In recent years new approaches like enrichment embedded kinematics, discontinuous Galerkin methods, isogeometric analysis, lagrange multipliers based formulations have been successfully used for quasi-static and dynamic fracture simulation. A CZM implemented in an augmented lagrangian formulation based on the model proposed by Lorentz [3] is developed and analyzed in this paper.This method is able to deal with unilateral contact and cohesive forces via a supplementary variable that enforces the jump displacement in so-called collocation points. It represents a suitable tool to study the debonding phenomena in composites with strongly different stiffness, avoiding ill-conditioning problems associated with penalty methods.The model stability and an error estimation following Brezzi theorem[4] are discussed. Some numerical examples that show the ability of this approach to capture inclusions debonding are included in the paper.