Insight into Rotational Hardening Rules: A New Proposition

Abstract

The concept of rotational hardening (RH) was introduced into constitutive model formulations in order to rotate a yield or bounding surface from the isotropic axis during either anisotropic consolidation or shearing. To properly account for the evolution of stress induced anisotropy during shearing, a suitable RH rule must be used. An improved RH rule is presented in this work. Although it incorporates aspects of several previous formulations, the improved RH rule includes provisions that allow it to more accurately simulate the response of anisotropically consolidated cohesive soils. This is especially true for overconsolidated specimens tested in extension. It was found that in order to properly match the experimental effective stress paths in such tests, it is necessary to accelerate the pace of rotation of the plastic potential towards the critical state line in extension; the higher the overconsolidation ratio, the faster should be the pace of rotation. © ASCE.