Modelling strain localization in soils using multilaminate model and homogenisation technique

Some numerical results relevant to the modelling of strain localization applying a homogenisation technique are presented in this paper. The onset of localization is captured using multilaminate model. After initiation of a shear band the material is treated as a composite material consisting of two constituents. A program employing a relatively simple deviatoric strain softening constitutive law with non-associated flow rule for the shear band material has been developed and a comprehensive study to evaluate the influence of individual input parameters has been performed. The aspect of the volume occupied by the shear band, an essential parameter for describing the composite material behaviour is considered. It is suggested that the volume fraction of the shear band which can be found by a parameter identification procedure simulating a biaxial test, is introduced as an additional independent variable.