Finite element analysis of localization and micro–macro structure relation in granular materials. Part II: Implementation and simulations

Abstract

The formation of strain localization influences the stability and stiffness of the soil mass or geosystem. The thickness of shear bands provides insight about overall strength and stiffness inside the granular body, and the shear band angle gives information about the failure surface in a given soil or soil mass. Thus, it is important to be able to predict when a shear band forms and how this zone of intense deformation is located and oriented within the granular medium. A rational finite element analysis for capturing the formation and development of shear bands has been performed and implemented by using a Cosserat continuum in finite element simulations. An extension of plane strain Drucker–Prager elastoplasticity to Cosserat continua is implemented in ABAQUS by using its User-defined ELement (UEL) option. The finite element formulation is discussed in the companion paper. The length scale–size effect relation has been investigated to understand the micro–macro structure relation. Several practical engineering problems are simulated in two dimensions by using the finite element code ABAQUS together with analyst-supplied extensions. The effect of Cosserat parameters on the finite element simulations has been simulated.