discretization of concrete behavior into four planar cases by elastoplastic multiplane model

a framework for development of constitutive models including damage progress, based on semi-micromechanical aspects of plasticity is proposed for concrete. the model uses sub-loading surface with multilaminate framework to provide kinematics and isotropic hardening/softening in the ascending/descending branches of loading and can be able to keep stress/stain paths histories for each plane separately. state of stresses on planes is divided to four basic stress patterns i.e. pure compression, increasing compression-and shear, decreasing compression-shear and tension-shear and used in derivation of plasticity equations. under this kind of categorized form the model is capable of predicting behavior of concrete under any stress/strain path such as uniaxial, biaxial and triaxial in the monotonic and cyclic loading, also this model is capable of predicting the effects of principal stress/strain axes rotations and consequent plastic flow and has the potential to simulate the behavior of material with anisotropy, fabric pattern, slip/weak planes and crack opening/closing. the material parameters of model are calibrated by optimum fitting of the basic test data available in the literature. the model results under both monotonic and cyclic loading have been compared with experimental results to show capability of model.