A micro finite-element model for soil behaviour: numerical validation

Abstract

This is the published version of the paper.This version of the publication may differ from the final published version. A micro finite-element (μFE) model capable of handling arbitrary shapes and deformable grains has been developed by the authors. The basis of this μFE model is to use a virtualised soil fabric obtained from micro computed tomography (μCT) of real sand to simulate grain-to-grain interaction in a framework of combined discrete-finite-element method. By incorporating grain deformation into the model, the contact response emerges from the interaction of contacting bodies and each irregular contact area will produce a unique response. A detailed numerical description of grain morphology and contact topology of a natural sand and the subsequent simulation are presented in the original paper. The present study focuses on the numerical validation of the constitutive contact behaviour against existent theories, for a single sphere and an assembly of spheres. The ability of the model to simulate elastic-plastic behaviour making use of the deformability of the grains is demonstrated. The unloading-reloading behaviour associated with the geometrical arrangement of the grains for a granular assembly under triaxial compression is examined in terms of energy dissipation quantities. Permanent repository link:

Numerical modelling of rough particle contacts subject to normal and tangential loading

“…In order to investigate the effect of loading history on the tangential stiffness, an elastic perfectly plastic constitutive model was assigned to the particles. This has a minor effect on the normal stiffness of glass beads as shown previously by Nadimi and Fonseca [22].…”

“…[17][18][19][20]). The present paper uses a micro finite-element (μFE) model proposed by Nadimi and Fonseca [21,22]. This numerical approach uses a more accurate representation of the grain morphology, including contact topology and grain roughness; which is critical to advance our understanding of contact behaviour and to derive empirical parameters for more realistic contact models.…”

Particle characterisation of rail sands for understanding tribological behaviour

“…It has been well established that particle shape has a significant impact on dynamic and quasistatic behaviour of particles [17]- [19]. Here, a representative sample of each type of sand was characterised by a Morphologi G3 (Malvern Panalytical Ltd., Malvern, UK).…”

A micro finite-element model for soil behaviour: experimental evaluation for sand under triaxial compression

“…O'Sullivan, 2011; Matsushima & Chang, 2011;Andrade, et al, 2012;Kawamoto, et al, 2018). Nadimi & Fonseca (2018a, 2018b proposed a micro Finite Element (µFE) model that virtualises the fabric of a natural sand obtained from micro Computed Tomography (μCT) to simulate the mechanical response under loading. In this model, the grainto-grain interactions are modelled in a framework of combined discrete-finite element method (Munjiza, 2004).…”