Dynamic fracture toughness determined using molecular dynamics

J. G. Swadener*, M. I. Baskes, M. Nastasi

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Molecular dynamics (MD) simulations of fracture in crystalline silicon are conducted in order to determine the dynamic fracture toughness. The MD simulations show how the potential energy released during fracture is partitioned into surface energy, energy stored in defects and kinetic energy. First, the MD fracture simulations are shown to produce brittle fracture and be in reasonable agreement with experimental results. Then dynamic fracture toughness is calculated as the sum of the surface energy and the energy stored as defects directly from the MD models. Models oriented to produce fracture on either (111) or (101) planes are used. For the (101) fracture orientation, equilibrium crack speeds of greater than 80% of the Rayleigh wave speed are obtained. Crack speeds initially show a steep increase with increasing energy release rate followed by a much more gradual increase. No plateau in crack speed is observed for static energy release rates up to 20 J/m2. At the point where the change in crack speed behavior occurs, the dynamic fracture toughness (Jd) is still within 10% of two times the surface energy (2γ0) and changing very slowly. From these MD simulations, it appears that the change in crack speed behavior is due to a change in the kinetic energy generation during dynamic fracture. In addition, MD simulations of facture in silicon with defects were conducted. The addition of defects increases the inelastic dissipation and the energy stored in defects.

Original languageEnglish
Title of host publication11th International Conference on Fracture 2005, ICF11
EditorsAlfredo Carpinteri
Pages5403-5408
Number of pages6
Volume7
Publication statusPublished - 1 Dec 2005
Event11th International Conference on Fracture 2005, ICF11 - Turin, Italy
Duration: 20 Mar 200525 Mar 2005

Conference

Conference11th International Conference on Fracture 2005, ICF11
CountryItaly
CityTurin
Period20/03/0525/03/05

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  • Cite this

    Swadener, J. G., Baskes, M. I., & Nastasi, M. (2005). Dynamic fracture toughness determined using molecular dynamics. In A. Carpinteri (Ed.), 11th International Conference on Fracture 2005, ICF11 (Vol. 7, pp. 5403-5408)