{"id":1290,"date":"2026-10-17T11:49:10","date_gmt":"2026-10-17T09:49:10","guid":{"rendered":"https:\/\/www.lmgc.univ-montp2.fr\/perso\/emilien-azema\/?p=1290"},"modified":"2026-10-17T11:50:34","modified_gmt":"2026-10-17T09:50:34","slug":"micromechanical-signature-of-representative-volume-conditions-in-granular-materials-particle-shape-effects-and-column-like-load-bearing-structures","status":"publish","type":"post","link":"https:\/\/www.lmgc.univ-montp2.fr\/perso\/emilien-azema\/2026\/10\/17\/micromechanical-signature-of-representative-volume-conditions-in-granular-materials-particle-shape-effects-and-column-like-load-bearing-structures\/","title":{"rendered":"Micromechanical signature of representative volume conditions in granular materials: Particle-shape effects and column-like load-bearing structures"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">J. Prommarin, P. Jitsangiam, M. Renouf, E. Az\u00e9ma,\u00a0<strong>Computer and G\u00e9otechnics<\/strong>\u00a0203, 108734 (2026)<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Representative volume conditions in coarse granular materials are investigated using three-dimensional Contact Dynamics simulations of drained triaxial compression tests. Dense assemblies of spherical particles and ballast-like polyhedral grains reconstructed from digitized railway ballast particles are compared to assess how particle shape influences the transition from finite-size-dominated behavior to representative bulk response. The nominal system-size ratio \ud835\udefc= \ud835\udc4a0 \u2215\ud835\udc51max is varied from 3 to 16. The results show that small systems exhibit pronounced stress fluctuations, lower internal coordination, broader normal force distributions, and strong sensitivity of the force-bearing network to specimen size. As \ud835\udefcnom increases, macroscopic quantities and micromechanical descriptors progressively stabilize. For both particle shapes, the macroscopic response becomes only weakly dependent on specimen size for \ud835\udefc \u2265 8. Particle shape strongly modifies the mechanisms of stress transmission. Polyhedral grains develop higher critical-state shear strength, larger contact anisotropy, and stronger tangential force anisotropy than spheres, reflecting enhanced interlocking and frictional mobilization. However, the apparent transition toward representative behavior occurs over a comparable nominal size range for both particle shapes. A dedicated filtering procedure is introduced to identify column-like structures, defined as unbranched chains of strongly loaded particles. Small systems contain long and frequently percolating structures spanning a large fraction of the specimen height, whereas larger systems exhibit shorter and more spatially distributed load-bearing paths. The progressive loss of systematically percolating column-like structures occurs over the broad size range in which several macroscopic and micromechanical<br>descriptors become less sensitive to specimen size. These results show that the organization of the force-bearing microstructure provides a complementary physical interpretation of the progressive reduction of finite-size effects.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>J. Prommarin, P. Jitsangiam, M. Renouf, E. Az\u00e9ma,\u00a0Computer and G\u00e9otechnics\u00a0203, 108734 (2026) Representative volume conditions in coarse granular materials are investigated using three-dimensional Contact Dynamics simulations of drained triaxial compression tests. Dense assemblies of spherical particles and ballast-like polyhedral grains reconstructed from digitized railway ballast particles are compared to assess how particle shape influences the [&hellip;]<\/p>\n","protected":false},"author":15,"featured_media":1291,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[],"class_list":["post-1290","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-articles"],"_links":{"self":[{"href":"https:\/\/www.lmgc.univ-montp2.fr\/perso\/emilien-azema\/wp-json\/wp\/v2\/posts\/1290","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.lmgc.univ-montp2.fr\/perso\/emilien-azema\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.lmgc.univ-montp2.fr\/perso\/emilien-azema\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.lmgc.univ-montp2.fr\/perso\/emilien-azema\/wp-json\/wp\/v2\/users\/15"}],"replies":[{"embeddable":true,"href":"https:\/\/www.lmgc.univ-montp2.fr\/perso\/emilien-azema\/wp-json\/wp\/v2\/comments?post=1290"}],"version-history":[{"count":1,"href":"https:\/\/www.lmgc.univ-montp2.fr\/perso\/emilien-azema\/wp-json\/wp\/v2\/posts\/1290\/revisions"}],"predecessor-version":[{"id":1292,"href":"https:\/\/www.lmgc.univ-montp2.fr\/perso\/emilien-azema\/wp-json\/wp\/v2\/posts\/1290\/revisions\/1292"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.lmgc.univ-montp2.fr\/perso\/emilien-azema\/wp-json\/wp\/v2\/media\/1291"}],"wp:attachment":[{"href":"https:\/\/www.lmgc.univ-montp2.fr\/perso\/emilien-azema\/wp-json\/wp\/v2\/media?parent=1290"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.lmgc.univ-montp2.fr\/perso\/emilien-azema\/wp-json\/wp\/v2\/categories?post=1290"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.lmgc.univ-montp2.fr\/perso\/emilien-azema\/wp-json\/wp\/v2\/tags?post=1290"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}