Discrete element modelling of railway ballast

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

“…A library of six ballast particles with sizes ranging from 13.2 to 53 mm was generated by connecting 25 to 40 spherical balls together for the current DEM analysis, as shown in Figure 5. The clumped particles has been adopted previously by Lim and McDowell (2005); Ferellec and McDowell (2008) to generate non-spherical particles. The typical particle shapes selected from real aggregates were mimicked by connecting a number of spherical balls at appropriate sizes and positions, as illustrated in Figure 5.…”

“…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.…”

Testing of Hungarian aggregates for railway ballast according to MSZ EN 13450: 2003

“…Further research work will also include freeze-thaw and magnesium-sulfate crystallizing tests, as well as computer simulation tests following Lim and McDowell (2005).…”

Effect of Rolling Resistance in Dem Models With Spherical Bodies

“…The first simulation is a large-scale oedometric test on railway ballast performed at the University of Nottingham by Lim [12]. The dimensions of the oedometric test are d = 300 mm in diameter and h = 150 mm in depth.…”