An implicit constitutive algorithm for finite strain Cam-clay elasto-plastic model

This work is directed toward the formulation and analysis of the modified Cam-clay critical state model within the framework of isotropic multiplicative finite strains. A suitable energy function, in which the shear modulus is made to depend on the mean pressure, is chosen allowing the hyperelastic response to be energy conserving. As a result of the use of Eulerian logarithmic stretches as strain measures in conjunction with an exponential approximation of the plastic flow rule, the small strain integration algorithms, and the corresponding consistent tangent operators, automatically extend to the finite strain regime. Numerical simulations are provided to demonstrate the stability and good performance of the proposed formulation. Copyright © 2000 John Wiley & Sons, Ltd.