Analysis of crack propagation of concrete under uniaxial compression based on double scalar variables damage-based cohesive crack model

In order to solve the problem for crack propagation of concrete under uniaxial compression, the viewpoint of damage mechanics is introduced into the description of the cohesive crack model, and a kind of double scalar variables damage-based cohesive crack model is presented in the framework of thermodynamics. Tensile and shear damage evolution curves is fitted according to the experimental data, and Coulomb's law is introduced into the shear damage evolution curve, which makes the proposed cohesive crack model more perfect. It can synthetically describe the stress-relative displacement relationship between the crack surface, not only for the single (Mode I and II) crack mode, but also the mixed (tension-shear and compression-shear) crack mode. In the numerical method, irregular interface element method is used to divide the triangle mesh randomly and then embed the interface element on the boundary of all triangular elements, so that the crack can propagate in the global of the specimen. Combined with the above two methods, the numerical simulation of the crack propagation of concrete under uniaxial the compression is carried out. Phenomena including multi-cracking, crack coalescence, and lateral expansion deformation during crack propagation of concrete can be described in the numerical simulation. © 2016, China Water Power Press. All right reserved.