Three-dimensional granular contact dynamics with rolling resistance

Micromechanics-Based Investigation of Fouled Ballast Using Large-Scale Triaxial Tests and Discrete Element Modeling

“…The discrete element method (DEM) proposed by Cundall and Strack (1979) has been widely used to examine the micromechanical properties of ballast materials (Lim and McDowell 2005;Lobo-Guerrero and Vallejo 2005;Tutumluer et al 2007;Bhandari et al 2009;O'sullivan and Cui 2009;Lobo-Guerrero and Vallejo 2010;Lu and McDowell 2010;Zhang et al 2013;Huang et al 2013;Tutumluer et al 2013;Mishra et al 2014;Indraratna et al 2015;Ngo et al 2015;Qian et al 2015), among others, but most of these numerical studies focused on fresh ballast. McDowell et al (2006) used the discrete element method to model largescale triaxial experiments of ballast aggregates reinforced with geogrids, and concluded that the DEM approach holds much promise as a tool for investigating granular aggregate assemblies.…”

Non-Smooth Contact Dynamics of Planar Masonry Structures Using Mathematical Programming

“…The dynamic model is formulated following the approach proposed in [6,7] for granular materials, though now detailed for two-dimensional assemblages of rectangular blocks.…”

“…Under the assumption of associative flow rule for displacement increments, the equilibrium equations (2), kinematic conditions (6-7) and sliding friction conditions (8) are equivalent to the following force-based problem [6][7][8][9]:…”

“…In this perspective, starting from previous studies in the field of granular materials [6,7], a non-smooth contact dynamic formulation for the analysis of masonry structures has been recently developed [8,9] and herein applied to a numerical case study taken from the literature [10] to show potentialities of the adopted modelling approach.…”

On the contact treatment of non-convex particles in the granular element method

“…• We extend a variational formulation of granular contact dynamics (CD) recently developed for convex particles [25][26][27][28]. This particular formulation, which is employed in this paper, is appealing because it provides a way for CD to be easily implemented and solved using off-the-shelf mathematical programming solvers.…”