Codes for integrating elasto-plastic constitutive models using explicit methods at small strain, including computation of the consistent tangent operator. For comparison, the Return Mapping Algorithm is also implemented.
The integration scheme is based on Sloan et al (2011), with two key differences: adaptive substepping is not yet implemented, and the numerical treatment of the stress path intersection with the yield surface is handled differently.
Two distinct constitutive models are considered: Modified Cam Clay and von Mises (perfect plasticity).
Several verification analyses are also provided, along with a naive FEM implementation for the mechanical problem.
Geomechanics sign conventions is used in this implementation (compressions are positive).
This code is distributed under BSD 3-Clause License.
If you find these codes useful for your work, please cite as follows:
- Monforte, L. and Rouainia, M. (2025) A novel consistent tangent operator for Runge-Kutta-based explicit stress integration for elasto-plastic models: application to the Modified Cam Clay model. International Journal for Numerical and Analytical Methods in Geomechanics https://doi.org/10.1002/nag.70016