Integration of elasto-plastic constitutive models infinite deformation: an explicit approach

Abstract

This paper highlights an explicit integration scheme for hyperelastic-based finite strains elasto-plastic models. One step update equations are obtained from the large deformation multiplicative elasto-plastic theory, where an exponential variation of the plastic deformation gradient is assumed. The material tangent matrix has the same formal structure as the usual small strains elasto-plastic tangent matrix. The basic algorithm to perform the stress integration, including an adaptive substepping scheme and a yield violation drift correction scheme, are also described. The accuracy and robustness of the proposal is assessed against several examples of typical geotechnical tests. Results from a convergence test suggest that, using an adaptive substepping scheme,the error of the local problem is independent of the step size.