Theoretical Simulation Of Stress-Strain Relations For Some Iraqiclays Using The Endochronic Model


A constitutive law can be defined as a mathematical functional relation between physical quantities such as stress and strain and may take other factors like time, temperature and additional material properties into account. In this paper, the endochronic model is used to predict the stress-strain relations of two Iraqi clays. This model is a viscoplastic one but without introducing a yield surface. It encompasses material behavior such that the current stress state is a function of strain history through a time scale called “intrinsic time” which is not the absolute time but a material property. The simulation showed that the model overestimates the strains for all cases studied. This may be attributed to the material parameters which require a parametric study to determine their actual values for Iraqi clays.