Faire avancer la sûreté nucléaire

La Recherchev2


Numerical simulation of the dynamic fracture of heterogeneous materials



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Titre du congrès :ACOMEN 2008 - Advanced Computational Methods in Engineering
Ville du congrès :Liège
Date du congrès :26/05/2008


A new numerical simulation framework dedicated to the study of the non smooth and complex dynamic fracture of heterogeneous materials has been developed. The proposed modelling of the dynamic fracture rests on both the concept of embedded Frictional Cohesive Zone Model (FCZM) and amultibody method in the context of the NonSmooth Contact Dynamics (NSCD).  The associated overall fracture properties of heterogeneous materials are obtained using a two field Finite Element formulation devoted to periodic numerical homogenization.
The FCZM-multibody model allows the simulation of crack initiation, propagation and post-fracture behavior: each mesh is considered as an independant body connected to another by vectorial, non linear, softening and non smooth relations such as frictional contact. The NSCD approach is used to treat these
non smooth relations without any regularization nor penalization.
The proposed periodic numerical homogenization scheme introduces a new discrete mapping in order to extend this NSCDframework to a two field formulation: the periodic displacement and the average deformation gradient.
An associated software, called X-per, is composed of three libraries with mixed Fotran90 and C++ programming and Object Oriented Programming: a library dedicated to nonsmooth contact dynamics approach (LMGC90) a library dedicated to periodic and standard finite element (PELICANS)
 and a library dedicated to bulk constitutive behaviors (MATLIB). This software allows to simulate, in finite deformation and without initiation criteria, the dynamic fracture of heterogeneous materials including functionally graded materials and smeared cracked media. The ability of this software and of
the proposed strategy is illustrated on an application related to the studies of the French "Institut de Radioprotection et de Sûreté Nucléaire" (IRSN) in the field of nuclear safety : the fracture of an heterogeneous material, the hydrided Zircaloy-4 constituting nuclear claddings, under transient loading.