TY - JOUR

T1 - A nonlocal cohesive zone model for finite thickness interfaces - Part I

T2 - Mathematical formulation and validation with molecular dynamics

AU - Paggi, Marco

AU - Wriggers, Peter

N1 - Funding information: The first author would like to thank the Alexander von Humboldt Foundation for supporting his research fellowship at the Institut für Kontinuumsmechanik, Leibniz Universität Hannover (Hannover, Germany) from February 1, 2010 to January 31, 2011.

PY - 2011/1/8

Y1 - 2011/1/8

N2 - A nonlocal cohesive zone model is derived taking into account the properties of finite thickness interfaces. The functional expression of the stress-separation relationship, which bridges the gap between continuum damage mechanics and nonlinear fracture mechanics, depends on the complex failure phenomena affecting the material microstructure of the interface region. More specifically, the shape of the nonlocal cohesive zone model is found to be dependent on the damage evolution. On the other hand, damage is in its turn a function of dissipative mechanisms occurring at lower length scales, such as dislocation motion, breaking of interatomic bonds, formation of free surfaces and microvoids, that are usually analyzed according to molecular dynamics. Hence, the relationship intercurring between the parameters of the damage law and the outcome of molecular dynamics simulations available in the literature is also established. Therefore, the proposed nonlocal cohesive zone model provides also the proper mathematical framework for interpreting molecular dynamics-based stress-separation relationships that are typically nonlocal, since they always refer to a finite number of atom layers.

AB - A nonlocal cohesive zone model is derived taking into account the properties of finite thickness interfaces. The functional expression of the stress-separation relationship, which bridges the gap between continuum damage mechanics and nonlinear fracture mechanics, depends on the complex failure phenomena affecting the material microstructure of the interface region. More specifically, the shape of the nonlocal cohesive zone model is found to be dependent on the damage evolution. On the other hand, damage is in its turn a function of dissipative mechanisms occurring at lower length scales, such as dislocation motion, breaking of interatomic bonds, formation of free surfaces and microvoids, that are usually analyzed according to molecular dynamics. Hence, the relationship intercurring between the parameters of the damage law and the outcome of molecular dynamics simulations available in the literature is also established. Therefore, the proposed nonlocal cohesive zone model provides also the proper mathematical framework for interpreting molecular dynamics-based stress-separation relationships that are typically nonlocal, since they always refer to a finite number of atom layers.

KW - Damage mechanics

KW - Finite thickness interfaces

KW - Molecular dynamics

KW - Multiscale approach

KW - Nonlinear fracture mechanics

KW - Nonlocal cohesive zone model

UR - http://www.scopus.com/inward/record.url?scp=79952008243&partnerID=8YFLogxK

U2 - 10.1016/j.commatsci.2010.12.024

DO - 10.1016/j.commatsci.2010.12.024

M3 - Article

AN - SCOPUS:79952008243

VL - 50

SP - 1625

EP - 1633

JO - Computational materials science

JF - Computational materials science

SN - 0927-0256

IS - 5

ER -