Development of an elastoplastic constitutive model in the framework of the multilaminate method for numerical analyses of geotechnical structures

Abstract

In this study, a generalized constitutive model, in which the yield and potential plastic surfaces do not need to be explicitly defined, is presented in the framework of the multilaminate method. In this framework, the constitutive relations are defined as the relationship between volumetric and deviatoric stresses and strains on several planes in different directions, called microplane. A new volumetric-deviatoric stress space is defined on the microplane, which has a volumetric component similar to the definition of mean stress. However, the deviatoric component is defined as the resultant of a normal deviatoric component and two shear components on the microplane. The use of the new innovative stress space facilitates the application of volumetric-deviatoric based constitutive models in the multilaminate framework. The results of the model for several types of clay and sand in drained and undrained conditions have been validated with experimental data and results presented by similar models and it was observed that the proposed model, in addition to the simplicity of the formulation, can correctly predict the behavior of sand and clay materials in different conditions.