Void coalescence processes quantified through atomistic and multiscale simulation |
| |
Authors: | R E Rudd E T Sepp?l? L M Dupuy and J Belak |
| |
Affiliation: | (1) Lawrence Livermore National Laboratory, University of California, L-045, Livermore, CA 94551-0808, USA;(2) Nokia Research Center, It?merenkatu 11–13, Helsinki, 00180, Finland |
| |
Abstract: | Simulation of ductile fracture at the atomic scale reveals many aspects of the fracture process including specific mechanisms
associated with void nucleation and growth as a precursor to fracture and the plastic deformation of the material surrounding
the voids and cracks. Recently we have studied void coalescence in ductile metals using large-scale atomistic and continuum
simulations. Here we review that work and present some related investigations. The atomistic simulations involve three-dimensional
strain-controlled multi-million atom molecular dynamics simulations of copper. The correlated growth of two voids during the
coalescence process leading to fracture is investigated, both in terms of its onset and the ensuing dynamical interactions.
Void interactions are quantified through the rate of reduction of the distance between the voids, through the correlated directional
growth of the voids, and through correlated shape evolution of the voids. The critical inter-void ligament distance marking
the onset of coalescence is shown to be approximately one void radius based on the quantification measurements used, independent
of the initial separation distance between the voids and the strain-rate of the expansion of the system. No pronounced shear
flow is found in the coalescence process. We also discuss a technique for optimizing the calculation of fine-scale information
on the fly for use in a coarse-scale simulation, and discuss the specific case of a fine-scale model that calculates void
growth explicitly feeding into a coarse-scale mechanics model to study damage localization.
The U.S. Government’s right to retain a non-exclusive, royalty-free license in and to any copyright is acknowledged. |
| |
Keywords: | Void growth Void coalescence Molecular dynamics Multiscale modeling Adaptive sampling |
本文献已被 SpringerLink 等数据库收录! |
|