Single hardening constitutive model for frictional materials I. Plastic potential Function

Based on review and evaluation of a large number of test data, a general three-dimensional plastic potential function expressed in terms of stress invariants is proposed. Three parameter values are required in this function, but one is redundant with one of the failure surface parameters. The plastic potential surface resembles an asymmetric cigar in the principal stress space. It includes tensile behavior of materials with effective cohesion. Its capabilities are examined by comparisons with experimental data from two- and three-dimensional tests on different frictional materials.