Elastoplastic Damage Model for Concrete Under Triaxial Compression and Reversed Cyclic Loading

The elastoplastic damage model for concrete is elaborated that can be applied to various stress states. In the previous study (2016) the 3D elastoplastic damage model, based on the Lubliner yield criterion and Drucker–Prager flow rule, was constructed. The simplified forms of the two functions set certain limitations on the calculations in true triaxial compression and high confining pressure. Improved accuracy of yield surface and potential plastic surface is required. The Menétrey–Willam yield criterion is adopted and analyzed in the effective stress space. The methods that define the hardening and softening functions through the volume plastic strain are no longer used in some successful 3D models since they employ double hardening and two-scalar damage to describe an increase in effective yield stress and degradation of stiffness. The suppression of damage evolution in triaxial compression is taken into account through the confining net decomposition of stress. The validation of specific parameters in the potential plastic function of the novel model is verified. The iteration return mapping algorithm is worked out and implemented. The reliability of the proposed model is corroborated by numerical simulation results compared with existing experimental data.