Closest-point projection method for the extended subloading surface model

This paper presents an implicit integration scheme based on the closest-point projection method for an unconventional plasticity model, the extended subloading surface model. A cutting-plane algorithm has already been formulated for the model. However, the present paper aims to introduce an alternative closest-projection return mapping scheme for resolving the elasto-plastic problem by improving the accuracy of the similarity center variable. Numerical examples are examined for monotonic and cyclic loading conditions to validate the results against a forward Euler method. The speed and accuracy of the resolution technique are determined, showing the local and global convergence rates and the iso-error map for the numerical algorithm.