Analyse multi-échelle de l'approche énergétique de la rupture des grains au sein de matériaux granulaires
- Autores: Younes Salami
- Directores de la Tesis: Eduardo Alonso Pérez de Agreda (dir. tes.)
- Lectura: En la Universitat Politècnica de Catalunya (UPC) ( España ) en 2017
- Idioma: español
- Tribunal Calificador de la Tesis: François Nicot (presid.), Ignacio Carol Vilarasu (secret.), Pierre Yves Hicher (voc.)
- Programa de doctorado: Programa de Doctorado en Ingeniería del Terreno por la Universidad Politécnica de Catalunya
- Materias:
- Enlaces
- Tesis en acceso abierto en: TDX
- Resumen
In recent years, multiscale analyses in granular soil mechanics have become more prevalent. The beauty of these approaches is that they can establish a link between the behaviors from a continuum level to their origins at the particle level.
In the micromechanical investigation of a granular medium, the particles are usually described as perfectly rigid bodies and their interactions as merely rolling, sliding and friction. Grain crushing however, the energy dissipating mechanism responsible for most of the plastic strains in granular soils and rockfill at higher stresses, is consequently neglected. The aim of this study is to improve our understanding of the process of grain crushing in soils through energy approaches. In order to do so, the problem was studied from both the continuum and the grain levels.
The first part of this research work is a theoretical investigation into the energy dynamics of breakage in a granular packing.
The results of this analysis allowed us to derive a constitutive law capable of predicting the breakage evolution. In order to extend the capabilities of the model to unsaturated conditions, the thermodynamic formulation was modified to include the coupling between the hydraulic effects and breakage.
The second part consists of an experimental study of the micromechanics of single grain fracture, and is structured into three sections, that represent the three main aspects of grain fracture: the effect of the surrounding grains, the mechanics of the crack and the effect of water on the development of the crack. In all of these studies, new experimental devices were designed, and novel imaging techniques were used.
