A Tensile Plastic Damage Constitutive Model of Concrete Based on Energy

Based on the theory of damage mechanics, continuum mechanics and irreversible thermodynamics, considering the coupling relation of plastic stain and damage, the certain function relation is supposed between the plastic free energy and the elastic free energy, so the damage energy release rate is defined. According to the Weibull distribution curve, the relationship between the damage variable and the energy release rate is established, thus the concrete tensile damage evolution equation is deduced. Finally, based on the plastic characteristics of concrete under the action of tensile load, the empirical formula of plastic deformation is obtained. Therefore, the tensile plastic damage constitutive model of concrete is established. The uniaxial tension test results and engineering examples are used for verification of the effectiveness and applicability of this model. Analysis results show that the tensile plasticity constitutive model can more truly reflect the concrete tensile damage evolution process.