Modeling Cracks in Clay at the Nanoscale through Molecular Dynamics
Publication: Geo-Congress 2023
ABSTRACT
In the present work, we carry out molecular dynamics (MD) simulations to investigate mechanism of crack in a single clay sheet. Uniaxial tension is applied to clay sheet in a strain-controlled manner. Crack initiates from the center of clay sheet and extends along the direction perpendicular to the loading direction. Finally crack extends through the whole slab and clay sheet is fractured into two halves. Bond breaking is first observed in silicon-oxygen bond, and later occurs in aluminum-oxygen bond. Numerical results show that crack propagation in single clay sheet is primarily contributed from bond breaking in Al-Ob and Si-Ob bonds. We find that crack length increases almost linearly with tensile strain. Atomic stress is calculated for both tetrahedral layer and octahedral layer considering the layered inhomogeneity of clay crystal structure. Stress intensity factor and energy release rate are computed based on MD simulation and are comparable to experimental results.
Get full access to this article
View all available purchase options and get full access to this chapter.
REFERENCES
Chandler, H. W. (1984). “The use of non-linear fracture mechanics to study the fracture properties of soils.” J. Agric. Eng. Res., 29(4), 321–327.
Cygan, R. T., Liang, J. J., and Kalinichev, A. G. (2004). “Molecular models of hydroxide, oxyhydroxide, and clay phases and the development of a general force field.” J. Phys. Chem. B., 108(4), 1255–1266.
Houben, M. E., Desbois, G., and Urai, J. L. (2013). “Pore morphology and distribution in the Shaly facies of Opalinus Clay (Mont Terri, Switzerland): Insights from representative 2D BIB–SEM investigations on mm to nm scale.” Appl. Clay Sci., 71, 82–97.
Likos, W. J., Song, X., Xiao, M., Cerato, A., and Lu, N. (2019). “Fundamental challenges in unsaturated soil mechanics”. In Geotechnical fundamentals for addressing new world challenges (pp. 209–236). Springer, Cham.
Mitchell, J. K., and Soga, K. (2005). Fundamentals of soil behavior (Vol. 3, p. USA). New York: John Wiley & Sons.
Menon, S., and Song, X. (2022a). “Computational coupled large‐deformation periporomechanics for dynamic failure and fracturing in variably saturated porous media.” Int. J. Numer. Methods Eng. DOI: https://doi.org/10.1002/nme.7109.
Menon, S., and Song, X. (2022b). “Computational multiphase periporomechanics for unguided cracking in unsaturated porous media.” Int. J. Numer. Methods Eng., 123(12), pp.2837–2871.
Plimpton, S. (1995). “Fast parallel algorithms for short-range molecular dynamics.” J. Comput. Phys., 117(1), 1–19.
Pouvreau, M., Greathouse, J. A., Cygan, R. T., and Kalinichev, A. G. (2017). “Structure of hydrated gibbsite and brucite edge surfaces: DFT results and further development of the ClayFF classical force field with metal-O-H angle bending terms.” J. Phys. Chem. C., 121(27), 14757–14771.
Song, X., Wang, M. C., and Zhang, K. (2018, January). “Molecular dynamics modeling of unsaturated clay-water systems at elevated temperature.” In The 7th International Conference on Unsaturated Soils 2018 (UNSAT2018)-Ng, Leung, Chiu and Zhou, eds. The Hong Kong University of Science and Technology, ISBN 978-988-78037-3-7.
Song, X., and Wang, M. C. (2019). “Molecular dynamics modeling of a partially saturated clay-water system at finite temperature.” Int. J. Numer. Anal. Methods Geomech., 43(13), 2129–2146.
Song, X., and Zhang, Z. (2022). “Determination of clay-water contact angle via molecular dynamics and deep-learning enhanced methods.” Acta Geotech., 17(2), 511–525.
Spray, J. G. (2010). “Frictional melting processes in planetary materials: From hypervelocity impact to earthquakes.” Annu. Rev. Earth Planet. Sci., 38(1), 221–254.
Wang, J. J., Zhu, J. G., Chiu, C. F., and Zhang, H. (2007). “Experimental study on fracture toughness and tensile strength of a clay.” Eng. Geol., 94(1-2), 65–75.
Zhang, Z., and Song, X. (2021). “Characterizing the Impact of Temperature on Clay-Water Contact Angle in Geomaterials during Extreme Events by Deep Learning Enhanced Method.” In Geo-Extreme 2021 (160–168).
Zhang, Z., and Song, X. (2022). “Nonequilibrium molecular dynamics (NEMD) modeling of nanoscale hydrodynamics of clay‐water system at elevated temperature.” Int. J. Numer. Anal. Methods Geomech., 46(5), 889–909.
Information & Authors
Information
Published In
History
Published online: Mar 23, 2023
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.