A novel approach to the complete stress strain curve for plastically damaged concrete under monotonic and cyclic loads

In this paper, new analytical formulations, which can be easily applied to normal and high-strength concretes under monotonic compressive and direct tensile loads, are proposed. Moreover, plastic damage model for concrete under uniaxial cyclic loading is also employed by introducing a simple damage function. The majority of published material models focuses on a certain type of concrete based on their testing results, which can be hardly applied to other types of concrete such as normal or high strength concrete. This paper presents a novel approach that can be applied to different types of concrete and highlights that the differences among testing results may come from the variations of strain at the peak stress. The damage phenomenon of concrete is simplified by a non-linear degradation of elastic modulus function, which in turn creates a linear stress-strain relation under cyclic loading. The damage function can be easily and quickly used to calibrate concrete properties for plastic damage model, which is very useful for industrial applications. Finally, the accuracy and pre-eminence of the proposed damage model are verified through comparison with experimental data and analytical solutions.