A numerical study on interface shearing of granular Cosserat materials

Ebrahimian, Babak; Noorzad, Ali; Alsaleh, Mustafa I.

doi:10.1080/19648189.2019.1627249

Cited by 10 publications

(8 citation statements)

References 67 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Besides the experimental studies, several numerical DEM and FEM analyses were carried out to investigate the interface behaviour in granular materials. Modelling the interface thickness within continuum mechanics using FEM can be only performed with constitutive models possessing a characteristic length of microstructure [9,10,20,49,50,53,55,59,60]. Moreover, the constitutive models have to take the salient behaviour of granular materials into account by considering major influential factors such as the initial density, pressure sensitivity and mean grain diameter of soils [52,54].…”

Section: Literature Overviewmentioning

confidence: 99%

“…The boundary conditions at interfaces with consideration of a characteristic length of microstructure were investigated following different enriched approaches, e.g. within micropolar elasto-plasticity [10,49,53,59], strain gradient elasto-plasticity [60] and micro-polar hypoplasticity [9,20,50]. Most of the calculations were carried out with very rough interfaces.…”

Section: Literature Overviewmentioning

confidence: 99%

See 1 more Smart Citation

3D DEM simulations of monotonic interface behaviour between cohesionless sand and rigid wall of different roughness

2020

View full text Add to dashboard Cite

The paper deals with three-dimensional simulations of a monotonic quasi-static interface behaviour between cohesionless sand and a rigid wall of different roughness during wall friction tests in a parallelly guided direct shear test under constant normal stress. Numerical modelling was carried out by the discrete element method (DEM) using spheres with contact moments to approximately capture a non-uniform particle shape. The varying wall surface topography was simulated by a regular mesh of triangular grooves (asperities) along the wall with a different height, distance and inclination. The calculations were carried out with different initial void ratios of sand and vertical normal stress. The focus was to quantify the effect of wall roughness on the evolution of mobilized wall friction and shear localization, also to specify the ratios between slip and rotation and between shear stress/force and couple stress/moment in the sand at the wall. DEM simulations were generally in good agreement with reported experimental results for similar interface roughness. The findings presented in this paper offer a new perspective on the understanding of the wall friction phenomenon in granular bodies.

show abstract

Section: Literature Overviewmentioning

confidence: 99%

Section: Literature Overviewmentioning

confidence: 99%

3D DEM simulations of monotonic interface behaviour between cohesionless sand and rigid wall of different roughness

2020

View full text Add to dashboard Cite

show abstract

“…Dove and Frost (1999) concluded that the interface of spherical, uniform particles against hard polymer (PolyVinyl Chloride-PVC) surfaces exhibits initiation of sliding at a significantly lower friction level compared with the case of angular, non-uniform particles. Ebrahimian et al (2019) presented a numerical investigation on the interface shearing behavior of a thin granular soil layer, encapsulated by two rigid surfaces of different roughnesses.…”

Section: Introductionmentioning

confidence: 99%

Large-scale experimental investigation of a low-cost PVC ‘sand-wich’ (PVC-s) seismic isolation for developing countries

et al. 2020

View full text Add to dashboard Cite

This study presents a large-scale experimental investigation on the seismic performance of an innovative, low-cost seismic isolation system for developing countries. It is based on the beneficial effect of the encapsulation of sand grains between two PVC surfaces on the initiation of sliding and the dissipation of seismic energy between the surfaces. A three-times scaled-down, idealized, seismically isolated model of a prototype single-story structure located in Nepal is subjected to an ensemble of recorded earthquake ground motion excitations. The experimentally derived response of the seismically isolated structure is compared with the response of the corresponding fixed-base structure. This system is part of a wider hybrid design approach where the structure is designed to resist the seismic forces at the design acceleration level. The seismic isolation system sets an upper bound to the response of the structure for ground motion excitations exceeding the design level.

show abstract

“…within micropolar elasto-plasticity [20,52,58], strain gradient elasto-plasticity [63] and micropolar hypoplasticity [53]. Some micropolar boundary conditions were proposed in [10,11,20,60] for describing the interface roughness. In [60], the 2D boundary conditions along the horizontal rigid interface included two ratios connected to the normalized interface roughness (a ratio of the micropolar rotation multiplied by the mean grain diameter and the horizontal displacement and a ratio between the horizontal shear stress multiplied by the mean grain diameter and the horizontal couple stress).…”

Section: Micropolar Boundary Conditionsmentioning

confidence: 99%

“…second-gradient, non-local or viscous terms, the characteristic length is determined with an inverse identification process of experimental data [2], [54]. Up to now, there do not exist consistent micropolar continuum boundary conditions for walls of different roughness [10,11,20,58,60]. There are some elastoplastic and hypoplastic models in the classical continuum for describing granular soil-structure interface behaviour (e.g.…”

Section: Introductionmentioning

confidence: 99%

Comparative 3D DEM simulations of sand–structure interfaces with similarly shaped clumps versus spheres with contact moments

2021

View full text Add to dashboard Cite

Three-dimensional simulations of a monotonic quasi-static interface behaviour between initially dense cohesionless sand and a rigid wall of different roughness during tests in a parallelly guided direct shear test under constant normal stress are presented. Numerical modelling was carried out by the discrete element method (DEM) using clumps in the form of convex non-symmetric irregularly shaped grains. The clumps had an aspect ratio of 1.5. A regular grid of triangular grooves (asperities) along the wall with a different height at the same distance was assumed. The numerical results with clumps were directly compared under the same conditions with our earlier DEM simulations using pure spheres with contact moments with respect to the peak and residual interface friction angle, width of the interface shear zone, ratio between grain slips and grain rotations, distribution of contact forces and stresses. The difference between the behaviour of clumps and pure spheres with contact moments proved to be noticeable in the post-peak regime due to a different particle shape. The rolling resistance model with pure spheres was proved to be limited for capturing particle shape effects. Three different boundary conditions along the interface were proposed for micropolar continua, considering grain rotations and grain slips, wall grain moments and wall grain forces, and normalized interface roughness. The numerical results in this paper offer a better understanding of the interface behaviour of granular bodies in DEM and FEM simulations.

show abstract

A numerical study on interface shearing of granular Cosserat materials

Cited by 10 publications

References 67 publications

3D DEM simulations of monotonic interface behaviour between cohesionless sand and rigid wall of different roughness

3D DEM simulations of monotonic interface behaviour between cohesionless sand and rigid wall of different roughness

Large-scale experimental investigation of a low-cost PVC ‘sand-wich’ (PVC-s) seismic isolation for developing countries

Comparative 3D DEM simulations of sand–structure interfaces with similarly shaped clumps versus spheres with contact moments

Contact Info

Product

Resources

About