Discrete element modelling of yielding and normal compression of sand

Particle Shape and Crushing Effects on Direct Shear Behavior Using DEM

“…At the same time, the study on the shear behavior, considering the particle shape and particle crushing of granular soils, has progressed considerably. Many researchers have selected the modeling technique of binding several circular particles with a constant bonding strength to simulate the geometrical shape of particles through numerical analysis using DEM (Jensen et al, 2001;McDowell and Harireche, 2002;Cheng et al, 2003). Jensen et al (1999) conducted a DEM-based numerical analysis to study the in‰uence of particle shape on shear behavior by using clustered particles and non-clustered particles.…”

3D assessment of fracture of sand particles using discrete element method

“…Particle breakage alters the dilatant behaviour of sands at high stresses (Bolton, 1986) and leads to the development of a linear normal compression line in onedimensional (1D) compression experiments (Coop & Lee, 1993;McDowell & Bolton, 1998). It is also directly correlated to plastic yielding (McDowell & Bolton, 1998;McDowell & Harireche, 2002b) and a major contributor to the accumulation of strain in cyclic loading (Harireche & McDowell, 2003). Furthermore, particle fracture influences the location of the critical state line (Cheng et al, 2005).…”

“…In the literature, individual particle fracture has been simulated using the DEM by treating the particle as an agglomerate of bonded spherical sub-particles (Robertson & Bolton, 2001;McDowell & Harireche, 2002a;Cheng et al, 2003) or by substituting individual rigid particles with a group of particles based on a certain failure criterion (Tsoungui et al, 1999;Lobo-Guerrero and Vallejo, 2005). McDowell & Harireche (2002a, 2002b and Cheng et al (2003) demonstrated that single sand particles can be modelled in the DEM using an agglomerate of spherical sub-particles bonded by contact bonds to capture the stress variation of single particle fracture, the uniaxial compression of granular assembly, and the plastic hardening and yielding of sand. The agglomerate is generally composed of regularly packed spheres that are linked by contact bonds and the variation in tensile strength of crushable particle was achieved by a random removal of about 20-50% of the sub-spheres to mimic experimental variation of tensile strength.…”

The Role of Particle Crushing in Granular Materials

“…Yielding is seen to occur at a volumetric (axial) strain of about 30%, which corresponds to the onset of bond fracture. Increasing the bond strength by a factor of 2 [24]. Figure 7 shows Fig.…”