Rotational kinematic hardening model for sand. Part I concept of rotating yield and plastic potential surfaces

Abstract

Abstract Existing kinematic hardening constitutive models are evaluated in the light of experimental studies on sand behavior during large stress reversals. An alternative approach is proposed which incorporates rotation and intersection of yield surfaces to achieve a better fit with experimental data. An existing isotropic hardening constitutive model forms the basic framework to which the rotational kinematic hardening mechanism is added. The behavior of the proposed plastic potential is verified by studying the experimentally obtained directions of plastic strain increment vectors superimposed on the stress space during large stress reversals. The new combined model preserves the behavior of the isotropic hardening model under monotonic loading conditions and the extension from isotropic to kinematic hardening is accomplished in a simple manner which avoids the introduction of complicated rules and new material parameters.