Symbolic algebra integration of soil elastoplastic models

This work analyses the time integration of elastoplastic models using implementation platforms with symbolic algebra capabilities. In such platforms, the variables and state functions involved in solving boundary value problems are considered entities continuous in time, thus the time integration of stresses and hardening parameters is always based on implicit schemes. The latter confers to the computation an accuracy that is inspected in this work by analysing the integration of the Clay and Sand Model. Finally, the advantages of using integration schemes in which the linearisation of the yield function is imposed to be zero when calculating the plastic multiplier are illustrated.