Micromechanics of randomly-generated particle packs for DEM simulations of granular materials using the stress-force-fabric relationship

Kamila R. Cassares Seko¹; Eduardo M. B. Campello¹

¹ Department of Structural and Geotechnical Engineering, University of São Paulo

doi:10.20906/CPS/CILAMCE2017-0582

Resumo

In this work, we investigate the micromechanics of packs of particles using the stress-force-fabric relationship (SFF). The packs are randomly generated using the particle-packing method of [1], and at first characterized through the procedure presented in [2]. We then compute the packs´ fabric tensor, fabric anisotropy tensor, normal contact force tensor and tangential friction force tensor, such that their microstructure is further characterized with respect to their granular fabric and principal contact directions (both normal and tangential). These features provide a good estimate to the degree of isotropy or anisotropy of the packs, and thus serve as indicators of "quality" of the packs and, ultimately, of the particle-packing technique. The average stress tensor of each pack, relating inter-particle contact forces and directions to the bulk stress response of the pack (and thereby providing an indirect relation between microscopic properties and macroscopic behaviour), is also computed and the results analysed. This work is a partial result of studies that are in development at Department of Structural and Geotechnical Engineering in University of São Paulo. REFERENCES [1] K. R. Cassares and E. M. B. Campello, "Rapid generation of particle packs at high packing ratios for DEM simulations of granular compacts", Lat Amer J Sol Struct., v.13, p.2016. [2] K. R. Cassares and E. M. B. Campello, "Characterization of the microstructure of randomly-generated particle packs for DEM simulations of granular materials", In: XXXVI Ibero-Latin American Congress on Computational Methods in Engineering (XXXVI CILAMCE), 2015, Rio de Janeiro.

Palavras-chave: Granular materials; Micromechanics; Stress-force-fabric relationship; Discrete element method