Numerical Integration of HISS Model with Finite Element Method: Strain Localization Analysis in Sand

Strain localization forming shear bands in the geomaterials has ensued significant damage to the structures. The present study is focused on the numerical simulation of strain localization using a finite element tool, namely ABAQUS. The hierarchical single surface model (HISS model) provides a suitable elastoplastic framework to predict the response of soils. The HISS model has been implemented in ABAQUS through the user-material subroutine (UMAT). This is subsequently validated with hydrostatic and triaxial compression tests on cubical specimen results using single-element simulations. The results from drained experiments available in the literature were used for validation. Furthermore, the model is used to analyze strain localization in the saturated cylindrical specimens under triaxial loading conditions. Finally, the effect of initial confining pressure on the onset of strain localization has been examined.