Numerical Simulation And Its Application Of Implicit Gradient Model In Three-dimensiona Damage

In this paper, the procreant background and basic theory of damage mechanics was summarized, several kinds of local damage model and nonlocal damage model of concrete were introduced, and their differential and applied foreground was analysed. The micro structure criterion was considered and the high-order distor- tion grads items was introduced when the basic formula and manipulative equation of nonlocal damage model was deducted so as to overcome mesh-dependence and sick localization in numerical simulation. The basic formula and manipulative equation of implicit gradient damage model were deducted, and were applied to finite element computation program. The defining principle of the interpolations functions was discussed emphatically in the computation process in this paper, the singularity for the strain field at the crack tip of concrete board with crack was studied,and the numerical extrapolated method was applied at the crack tip. The damage of concrete plate with crack of plane-stress and three-dimensional dam- age of three curved beems were simulated. The curve of load-displacement and nephogram of damage distributing with three mesh were gained, and the curve of damage evolvement was analysed. Numerical calculation show that the implicit gradient model can simulate commendably the speciality of damage for concrete,and its distributing of damage and carrying capacity is no sensitivity to mesh- diminished. The pathological mesh-dependence and zero energy consuming are overcome.