| While concrete has been applied as a structural material since ancient times, the true nature and behavioral characteristics of the material have only recently begun to unfold. The theories of plasticity, fracture mechanics, and damage mechanics have all been applied in various methods to try to predict the actual response of concrete under uniaxial, multiaxial, monotonic, and cyclic loading scenarios. However, in its truest form concrete is a material whose performance is governed by a subtle interaction of cohesive and frictional strengths, and the aforementioned theories cannot, by themselves, capture both of these phenomena.; Therefore, a new constitutive model is proposed which applies the theories of plasticity and damage mechanics in order to capture the effects of slip deformation and decohesion in concrete. Combining these two theories into one allows the model to accurately capture not only the hardening/softening behavior of concrete under compressive loading, but also the decrease of material stiffness under tension. In addition, the interaction of volumetric and deviatoric stresses attributed to the so-called Reynolds effect in frictional materials is captured by the model.; The characteristics and behavior of the model are presented through analyses on the continuum level under tensile, compressive, and shear loading schemes. The numerical results are compared to laboratory experimental results whenever possible. In addition, the localization aspects of the model are investigated, and failure analyses performed for various loading scenarios. |
