Numerical Simulation of Concrete Structures Based on Damage Theory

Degradation of material properties could be considered a micro damage mechanism of concrete structures, which introduces macro behavior with stiffness delimitation and bearing loss of structural system. In this essay, a framework of damage constitutive relationship of ductile solids based on irreversible thermodynamics was presented and exploited in numerical implementation of concrete material. A yielding criterion was expressed in time discrete formulation. The algorithmic functions of stress, strain and damage variable were supplied on the ground of discrete time step. Two-step map returning method (closest project point method) based upon implicit backward Euler scheme was expressed according to the stress upgrades operation, with plastic potential being equivalent to yielding function. The plastic parameter and consistent tangent stiffness tensor were deduced which meet constitutive integral and convergent condition assumption. Comparison between experiment and simulation indicated validity and rationality of the model and algorithm described previously.