Damage constitutive model of concrete under cyclic loading

Research of concrete constitutive model is actually to study constitutive behavior concrete.Cumulate deformation of material will cause interior damage of structure under exterior load and the entire structure will collapse due to damage of concrete.Due to damage theory by Najar given,a new segments curves damage variable model of concrete compression and damage model of concrete tension with soft curve segment is investigated and equations is put forward to about damage variable and evolvement with variety degrees of concrete.In order to testify the validity of the model,the calculated result are compared with the existing constitutive model and resulting shows that the proposed model is agreed with the existing model.Advanced of this new method is there are different damage equations due to concrete degrees and can dynamically analysis concrete damage.Based on hysteresis rules of exist concrete under cyclic loading,damage constitutive model is suggested under one cyclic,stress deterioration,crack effect,carrying capacity decline and stiffness degenerate of concrete under cyclic loading are considered in this model.