Thermodynamic Modeling of the Elastoplastic-Damage Model for Concrete

Abstract

A new coupled damage-plastic constitutive model is presented for modeling the nonlinear behavior of concrete in the small strain space. The active damage tensor concept and the closure effect are presented by considering both the state of the strain and the boundary condition of the crack. A new Helmholtz free energy function (HFEF) is introduced with the existence of a dissipation plastic potential in the stain space. The staggering process between the plastic and damage states has been developed through the HFEF formulation and simultaneously satisfies the consistency conditions. The plastic calculations are formulated in the effective stress regime by developing a 3D plasticity model. The damage surface and damage evolution are formulated based on the accumulated plastic history. The numerical results from the proposed model have been compared with both the experimental data from the literature and with another numerical damage model. Finally, the model exhibits its ability to be applied to analyze various concrete structures.