@proceedings {351,
	title = {Numerical simulation of granular media composed with irregular polyhedral particles: effect of particles{\textquoteright} angularity},
	journal = {2nd International Conference on Particle-Based Methods - Fundamentals and Applications (Particles)},
	volume = {PARTICLE-BASED METHODS II: FUNDAMENTALS AND APPLICATIONS},
	year = {2015},
	month = {Feb-02-2015},
	pages = {222-228},
	address = {OCT 26-28 2011 Barcelona, SPAIN},
	abstract = {<p>We use contact dynamic simulations to perform a systematic investigation of the effects of particles shape angularity on mechanicals response in sheared granular ma-terials. The particles are irregular polyhedra with varying numbers of face from spheres to \&quot;double pyramid\&quot; shape with a constant aspect ratio. We study the quasi-static behav-ior, structural and force anisotropies of several packings subjected to triaxial compression. An interesting finding is that the shear strength first increases with angularity up to a maximum value and then saturates as the particles become more angular. Analyzing the anisotropies induced by the angular distributions of contacts and forces orientations, we show that the saturation of the shear strength at higher angularities is a consequence of fall-off of the texture anisotropies compensated by an increase of the tangential force anisotropy. This is attributed to the fact that at higher angularity, particles are bet-ter connected (or surrounded) leading to an increase of friction mobilization in order to achieve the deformation. Moreover, the most angular particles also have very few sides so that, this effect is enhanced by the increase of the proportion of face-side and side-side contacts with angularity.</p>
},
	keywords = {angularity, force transmission, Granular Materials, particle shape, texture},
	url = {https://hal.archives-ouvertes.fr/hal-01112373},
	author = {Emilien Az{\'e}ma and Farhang Radja{\"\i} and Dubois, Fr{\'e}d{\'e}ric},
	editor = {Onate, E and Owen, DRJ}
}
@proceedings {368,
	title = {Comparison of the effects of rolling resistance and angularity in sheared granular media},
	journal = {7th International Conference on Micromechanics of Granular Media (Powders and Grains)},
	volume = {Book Series: AIP Conference Proceedings  POWDERS AND GRAINS 2013},
	year = {2013},
	month = {Jul-2013},
	pages = {891-894},
	address = {JUL 08-12 2013 Sydney, AUSTRALIA},
	abstract = {<p>In this paper, we compare the effect of rolling resistance at the contacts in granular systems composed of disks with the effect of angularity in granular systems composed of regular polygonal particles. For this purpose, we use contact dynamics simulations. By means of a simple shear numerical device, we investigate the mechanical behavior of these materials in the steady state in terms of shear strength, solid fraction, force and fabric anisotropies, and probability distribution of contact forces. We find that, based on the energy dissipation associated with relative rotation between two particles in contact, the effect of rolling resistance can explicitly be identified with that of the number of sides in a regular polygonal particle. This finding supports the use of rolling resistance as a shape parameter accounting for particle angularity and shows unambiguously that one of the main influencing factors behind the mechanical behavior of granular systems composed of noncircular particles is the partial hindrance of rotations as a result of angular particle shape.</p>
},
	keywords = {angularity, anisotropy, force distribution, Granular material, rolling resistance, Shear strength, solid fraction},
	url = {https://hal.archives-ouvertes.fr/hal-00842799},
	author = {Estrada, Nicolas and Emilien Az{\'e}ma and Farhang Radja{\"\i} and Taboada, Alfredo},
	editor = {Yu, A and Dong, K and Yang, R}
}
