TY - JOUR

T1 - Constitutive model with rotating active plane and true stress

AU - Zubelewicz, Aleksander

AU - Bažant, Zdeněk P.

PY - 1987/3

Y1 - 1987/3

N2 - A novel constitutive model for concrete, which approximately describes the basic known test data on nonlinear triaxial behavior including strainsoftening, is presented. The model rests on two basic ideas: (1) The stress-strain relation is defined as the relation between the normal and shear components of stress and strain on a certain special plane, called the active plane, the orientation of which varies as a function of accumulated inelastic strains; and (2) the stress-strain relation is written in terms of microstresses or true stresses that are obtained as the macrostresses divided by the resisting area fraction of the material. Strain-softening is obtained principally due to decrease of this area fraction. Thus, an incremental plasticity law satisfying the normality rule may be introduced on the microlevel, and a symmetric stiffness matrix is obtained. The loading surface for the active plane on the microlevel is an ellipse in the normal-shear stress space, similar to the critical state theory for soils. The model involves only six empirical inelastic material parameters, for which a simple sequential identification procedure is developed.

AB - A novel constitutive model for concrete, which approximately describes the basic known test data on nonlinear triaxial behavior including strainsoftening, is presented. The model rests on two basic ideas: (1) The stress-strain relation is defined as the relation between the normal and shear components of stress and strain on a certain special plane, called the active plane, the orientation of which varies as a function of accumulated inelastic strains; and (2) the stress-strain relation is written in terms of microstresses or true stresses that are obtained as the macrostresses divided by the resisting area fraction of the material. Strain-softening is obtained principally due to decrease of this area fraction. Thus, an incremental plasticity law satisfying the normality rule may be introduced on the microlevel, and a symmetric stiffness matrix is obtained. The loading surface for the active plane on the microlevel is an ellipse in the normal-shear stress space, similar to the critical state theory for soils. The model involves only six empirical inelastic material parameters, for which a simple sequential identification procedure is developed.

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U2 - 10.1061/(ASCE)0733-9399(1987)113:3(398)

DO - 10.1061/(ASCE)0733-9399(1987)113:3(398)

M3 - Article

AN - SCOPUS:0023306118

SN - 0733-9399

VL - 113

SP - 398

EP - 416

JO - Journal of Engineering Mechanics

JF - Journal of Engineering Mechanics

IS - 3

ER -