Damping and Particle Mass in DEM Simulations under Gravity
Publication: Journal of Engineering Mechanics
Volume 141, Issue 6
Abstract
This paper presents a study on the input parameters used in the discrete-element simulations with gravity. Input parameters of the discrete-element method (DEM) include particle mass (density), damping, gravity constant, strain rate, and contact relationship. This paper focuses on particle mass and damping. The samples consisted of two kinds of ellipsoidal particles. The unit weight of the particles is constant. Samples are prepared by depositing particles under gravity. The final bulk densities of the samples are different for different damping and particle mass. The effect of the reduction of particle density is similar to that of the reduction of damping in sample preparation. For the samples, static equilibrium can be achieved with a damping ratio greater than 0.24%. When the damping ratio is less than 0.24%, some particles are oscillating. The oscillation cannot be reduced with further relaxation. Undrained simulations are carried out on these samples. Shear strength increases with the increase of damping as expected. Different undrained stress paths are found for simulations of loose samples with different damping. For simulations of loose samples with the same damping ratio, particle density affects the results slightly. However, the effect of damping and particle mass is negligible for dense samples. The ultimate shear strength of the granular material is not affected by either damping or particle mass.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
This study was partially sponsored by the National Natural Science Foundation of China (Nos. 51379161 and 51322905).
References
Barreto, D., and O’Sullivan, C. (2012). “The influence of inter-particle friction and the intermediate stress ratio on soil response under generalised stress conditions.” Granular Matter, 14(4), 505–521.
Belytschko, T. (1983). “An overview of semidiscretization and time integration procedures.” Computational methods in mechanics: Computational methods for transient analysis, T. Belytschko and T. J. R. Hughes, eds., Vol. 1, North-Holland, New York, 1–65.
Chung, Y. C., and Ooi, J. Y. (2007). “Influence of discrete element model parameters on bulk behavior of a granular solid under confined compression.” Part. Sci. Technol, 26(1), 83–96.
Grima, A. P., and Wypych, P. W. (2009). “Investigations into calibration for discrete element modelling of granular materials.” Proc., 6th Int. Conf. for Conveying and Handling of Particulate Solids, Engineers Australia, Barton, Australia, 69–76.
Lin, X., and Ng, T.-T. (1997). “A three dimensional discrete element model using arrays of ellipsoids.” Géotechnique, 47(2), 319–329.
Ng, T.-T. (2006). “Input parameters of discrete element methods.” J. Eng. Mech., 723–729.
Ng, T.-T. (2013). “Numerical study of a granular material in various gravity environments.” J. Eng. Mech., 489–495.
Vaid, Y. P., and Negussey, D. (1988). “Preparation of reconstituted sand specimens.” Advanced triaxial testing of soil and rock (ASTM STP 977), R. T. Donaghe, R. C. Chaney, and M. L. Silver, eds., ASTM, West Conshohocken, PA, 405–417.
Xu, Y., Xu, C., Zhou, Z., Du, J., and Hu, D. (2010). “2D DEM simulation of particle mixing in rotating drum: A parametric study.” Particuology, 8(2), 141–149.
Information & Authors
Information
Published In
Journal of Engineering Mechanics
Volume 141 • Issue 6 • June 2015
Copyright
© 2014 American Society of Civil Engineers.
History
Received: Mar 27, 2014
Accepted: Oct 2, 2014
Published online: Oct 30, 2014
Published in print: Jun 1, 2015
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.