Halo approach to model cracks initiation and propagation in 3D Discrete Element Method simulation of homogeneous and heterogeneous materials

W. Leclerc (1) , A. Ammar (2) , D. Moukadiri , T. Dridi , M. Guessasma (1)

1 LTI - Laboratoire des technologies innovantes - UR UPJV 3899
2 UM5 - Université Mohammed V de Rabat [Agdal]

The present contribution deals with an investigation of the halo approach to simulate cracks initiation and propagation in homogeneous and heterogeneous materials by Discrete Element Method using the hybrid lattice-particle model. Recent developments highlighted that the halo, which can be described as a spherical interaction domain of controlled size, enables to efficiently reduce the intrinsic dispersion of the stress in discrete modelling. This paper aims at studying the benefits of such a concept to provide suitable cracks initiation and propagation through two applications: the diametral compression test of a cylindrical tablet composed of a brittle marble and the failure process of a flax fibre/bio-based composite material. For that purpose, based on an original process ensuring the connexity within each halo during cracks propagation, numerical simulations are led to determine the influence of the halo size on the validity of stress field before damaging, and ensuing failure process with respect to theoretical expectations and finite element data. Results exhibit that a minimum halo diameter about 15 times the particles size is required to obtain proper stress fields and crack patterns, but care must be taken to avoid too large halos which could lead to excessive stress smoothing and unrealistic cracks.

Domaines: Sciences de l'ingénieur [physics]

W. Leclerc, A. Ammar, D. Moukadiri, T. Dridi, M. Guessasma. Halo approach to model cracks initiation and propagation in 3D Discrete Element Method simulation of homogeneous and heterogeneous materials. Composite Structures, 2021, 259, ⟨10.1016/j.compstruct.2020.113222⟩. ⟨hal-03630488⟩