A microstructural model based on the evolution of the distribution of the particle contacts is proposed to describe the constitutive bulk behaviour of an assembly of idealised cohesionless granular structure. The model is formulated in principal direction space and the kinematics of the granular assembly is derived for two-dimensional problems only. The evolution of the distribution of the particle contacts results from an analysis based on the second law of thermodynamics. By postulating a rate for this evolution, a new dimension is introduced - the time scale - which, subsequently, allows the study of its influence on the particulate media processes. The number of model parameters is limited to three for the evolution of average contact numbers following the principal directions. The assessment of the strain response based on the particle contact evolution requires five additional model parameters. Although the link between the particle contact evolution and the strains could be improved, the predicted behaviour so far has shown remarkable similarity to the stress-strain behaviour observed from experiments under various loading conditions, including the time effects.
|Translated title of the contribution||A micromechanical description of granular assemblies through entropy principle|
|Number of pages||21|
|Publication status||Published - 2007|