Matrix Stress-strain Working Method for Determining the Effective Plastic Strain

A matrix stress and strain implementation is made that becomes simpler than tensor notation as usual. The effective stress is calculated using the indicated matrix notation, starting from a deviatoric stress state. The effective stress defines a functional flow condition which, besides the principle of normality, solves an equation for the incremental plastic deformation. The plastic work is determined, as usual, from the state of stresses and strains. Finally, the effective plastic strain is obtained as a function of the plastic working and the effective stress, both in the case of plastic deformation at constant volume and with variable volume model.