Boundary effects on behaviour of granular material during plane strain compression

Abstract

The paper investigates the boundary effect on the behaviour of granular materials during plane strain compression using finite element method. A micro-polar hypoplastic constitutive model was used. The numerical calculations were carried out with different initial densities and boundary conditions. The behaviour of initially dense, medium dense and loose sand specimen with very smooth or very rough horizontal boundary was investigated. The formation of shear zones gave rise to different global and local stress and strain. Comparisons of the mobilized internal friction, dilatancy and non-coaxiality between global and local quantities were made.

Experimental Study on Shear Localisation in Granular Materials Within Combined Strain and Stress Field

“…These parameters are determined from global measurements of forces and displacements at a specimen’s boundaries and vary from their local quantities, which cannot be easily measured. The difference between local and global (averaged over the whole volume of the sample) measurements is mainly owing to localised deformation, concentrated within narrow shear zones, but also because of imperfect boundaries of the test equipment [4, 5]. The effect of localised deformation and imperfect boundary conditions have to be separated to distinguish the material behaviour from the structural one.…”