@article {667, title = {Parallel implicit contact algorithm for soft particle systems}, journal = {Computer Physics Communications}, volume = {237}, year = {2019}, month = {Apr-01-2019}, pages = {17 - 25}, abstract = {

This paper presents a numerical technique to model soft particle materials in which the particles can undergo large deformations. It combines an implicit finite strain formalism of the Material Point Method and the Contact Dynamics method. In this framework, the large deformations of individual particles as well as their collective interactions are treated consistently. In order to reduce the computational cost, this method is parallelised using the Message Passing Interface (MPI) strategy. Using this approach, we investigate the uniaxial compaction of 2D packings composed of particles governed by a Neo-Hookean material behaviour. We consider compressibility rates ranging from fully compressible to incompressible particles. The packing deformation mechanism is a combination of both particle rearrangements and large deformations, and leads to high packing fractions beyond the jamming state. We show that the packing strength declines when the particle compressibility decreases, and the packing can deform considerably. We also discuss the evolution of the connectivity of the particles and particle deformation distributions in the packing. (C) 2018 Elsevier B.V. All rights reserved.

}, issn = {00104655}, doi = {10.1016/j.cpc.2018.10.030}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0010465518303904}, author = {Saeid Nezamabadi and Frank, Xavier and Jean-Yves Delenne and Julien Averseng and Farhang Radja{\"\i}} } @article {627, title = {Multiscale modeling for bioresources and bioproducts}, journal = {Innovative Food Science \& Emerging Technologies}, volume = {46}, year = {2018}, month = {Avr-2018}, pages = {41 - 53}, abstract = {

Designing and processing complex matter and materials are key objectives of bioresource and bioproduct research. Modeling approaches targeting such systems have to account for their two main sources of complexity: their intrinsic multi-scale nature; and the variability and heterogeneity inherent to all living systems. Here we provide insight into methods developed at the Food \& Bioproduct Engineering division (CEPIA) of the French National Institute of Agricultural Research (INRA). This brief survey focuses on innovative research lines that tackle complexity by mobilizing different approaches with complementary objectives. On one hand cognitive approaches aim to uncover the basic mechanisms and laws underlying the emerging collective properties and macroscopic behavior of soft-matter and granular systems, using numerical and experimental methods borrowed from physics and mechanics. The corresponding case studies are dedicated to the structuring and phase behavior of biopolymers, powders and granular materials, and to the evolution of these structures caused by external constraints. On the other hand machine learning approaches can deal with process optimizations and outcome predictions by extracting useful information and correlations from huge datasets built from experiments at different length scales and in heterogeneous conditions. These predictive methods are illustrated in the context of cheese ripening, grape maturity prediction and bacterial production.

}, issn = {14668564}, doi = {10.1016/j.ifset.2017.09.015}, url = {https://linkinghub.elsevier.com/retrieve/pii/S1466856417302230}, author = {Barnabe, M. and Blanc, Nicolas and Chabin, T. and Jean-Yves Delenne and Duri, A. and Frank, Xavier and Hugouvieux, V. and Lutton, E. and Mabille, F. and Saeid Nezamabadi and Perrot, N. and Farhang Radja{\"\i} and Ruiz, T. and Tonda, A.} } @proceedings {337, title = {MPM with Frictional Contact for Application to Soft Particulate Materials}, journal = {PROCEEDINGS OF THE 1ST INTERNATIONAL CONFERENCE ON THE MATERIAL POINT METHOD (MPM 2017) Book Series: Procedia Engineering }, volume = {175}, year = {2017}, month = {Mar-23-2017}, pages = {141 - 147}, publisher = {Elsevier Ltd.}, address = {JAN 10-13, 2017, Delft, NETHERLANDS}, abstract = {

Soft particle materials are composed of discrete particles that can undergo large deformations without rupture. Most food products, many powders, colloidal pastes, vesicles and biological cells are soft particle systems. In order to model such materials, we present an efficient numerical approach combining an implicit formulation of the Material Point Method (MPM) and Contact Dynamics (CD) method. The MPM deals with bulk variables of an individual particle by discretizing it as a collection of material points, whereas the CD allows for the treatment of frictional contacts between particles. This model is applied for the simulation of the uniaxial compression of 2D soft-particle packings. The compaction is a nonlinear process in which new contacts are formed between particles and the contact areas increase. The change of particle shapes allows these materials to reach high packing fraction. We find that the contact specific surface, the orientation anisotropy and the aspect ratio of particles increase as a function of the packing fraction but at different rates. We also evidence the effect of friction, which favors strong stress chains and thus the elongation of particles, leading to larger values of the orientation anisotropy and the aspect ratio at a given level of packing fraction as compared to a frictionless particle packing.

}, issn = {18777058}, doi = {10.1016/j.proeng.2017.01.044}, author = {Saeid Nezamabadi and Thanh Hai Nguyen and Jean-Yves Delenne and Julien Averseng and Frank, Xavier and Farhang Radja{\"\i}}, editor = {Rohe, A and Kenichi Soga and Teunissen, H} } @article {608, title = {Numerical modeling of the tensile strength of a biological granular aggregate: Effect of the particle size distribution}, journal = {EPJ Web of Conferences}, volume = {140}, year = {2017}, month = {Jun-30-2017}, pages = {Article Number 08013}, abstract = {

Wheat grains can be considered as a natural cemented granular material. They are milled under high forces to produce food products such as flour. The major part of the grain is the so-called starchy endosperm. It contains stiff starch granules, which show a multi-modal size distribution, and a softer protein matrix that surrounds the granules. Experimental milling studies and numerical simulations are going hand in hand to better understand the fragmentation behavior of this biological material and to improve milling performance. We present a numerical study of the effect of granule size distribution on the strength of such a cemented granular material. Samples of bi-modal starch granule size distribution were created and submitted to uniaxial tension, using a peridynamics method. We show that, when compared to the effects of starch-protein interface adhesion and voids, the granule size distribution has a limited effect on the samples\’ yield stress.

}, doi = {10.1051/epjconf/201714008013}, url = {http://www.epj-conferences.org/10.1051/epjconf/201714008013}, author = {Heinze, Karsta and Frank, Xavier and Val{\'e}rie Lullien-Pellerina and George, Matthieu and Farhang Radja{\"\i} and Jean-Yves Delenne}, editor = {Saeid Nezamabadi and Luding, S.} } @article {603, title = {Numerical study of the failure of materials embedding soft to hard particles}, journal = {EPJ Web of Conferences}, volume = {140}, year = {2017}, month = {Jun-30-2017}, pages = {Article Number 02029}, abstract = {

In this study, we use a bond-based peridynamic approach to investigate the mechanical strength and cracking of composite materials with spherical inclusions. The total volume fraction of particles and the particle-matrix toughness ratio were varied to cover a range of soft to hard inclusions. The mean particle damage was characterized together with crack patterns at a sub-particle scale. Three types of crack patterns are identified depending on the toughness ratio.

}, doi = {10.1051/epjconf/201714002029}, url = {http://www.epj-conferences.org/10.1051/epjconf/201714002029}, author = {Frank, Xavier and Jean-Yves Delenne and Farhang Radja{\"\i}}, editor = {Saeid Nezamabadi and Luding, S.} } @article {597, title = {Peridynamics simulation of the comminution of particles containing microcraks}, journal = {EPJ Web of Conferences}, volume = {140}, year = {2017}, month = {Jun-30-2017}, pages = {Article Number 07018}, abstract = {

In this study, we rely on a \’bond-based\’ peridynamic approach to investigate the strength and failure of 2D particles containing a collection of 1D microcracks. The mechanical tests were performed on disks under diametral compression. In an extensive parametric study, the distribution of microcracks was varied for different particle sizes. The evolution of yield stress with diameter and the probability of failure in terms of Weibull distributions are investigated in detail. Finally, by means of a floodfill algorithm, we analyze the variation of the mean fragment size as a function of the density of defects.

}, doi = {10.1051/epjconf/201714007018}, url = {http://www.epj-conferences.org/10.1051/epjconf/201714007018}, author = {Blanc, Nicolas and Frank, Xavier and Mayer-Laigle, Claire and Farhang Radja{\"\i} and Jean-Yves Delenne}, editor = {Saeid Nezamabadi and Luding, S. and Jean-Yves Delenne} }