Abstract
Many localized deformations are observed in the ultimate state of structural and geotechnical materials. Since it is important to predict how such localized deformations are initiated and developed, we propose a constitutive model which is represented by small number of parameters and yields no difficulty in numerical calculations. The model includes a micro-slip mechanism as the second inelastic part of deformation after the condition of localization of deformation by Hill is satisfied. The micro-slips are formulated by the double-slip theory. Numerical check with standard tensile tests shows stable numerical calculation up to very large deformation state. Compression tests and indentation problems are solved to show eligibility of the present model.
