Damage constitutive model for concrete under uniaxial stress conditions

Applying the theory of damage mechanics, supposing the numerical values between the ratio of unloading elastic modulus to the initial elastic modulus and the ratio of residual elastic strain energy after unloading to the total strain energy are equivalent, this paper presents a new damage constitutive model for concrete under uniaxial stress conditions. Thus the elastic modulus damage is combined with energy damage, and the numerical value of damage variable of concrete under uniaxial stress conditions is determined by numerical method. Based on the unified calculation method of stress-strain relationship of various strength of concrete under uniaxial stress conditions, through numerical integration and regression analysis, the evolvement law of damage and damage constitutive model for concrete under uniaxial stress conditions are proposed.The results show that the model can describe the response of concrete under uniaxial cyclic loading. It is indicated that the analysis results of the damage constitutive are in good agreement with the experiment ones. This work is a base for the further researches on the nonlinear element analysis of concrete structures under reversed cyclic loading. 2 tabs, 4 figs, 12 refs.