RHEOLOGICAL MODEL FOR CYCLIC LOADING OF CONCRETE.

A rheological stochastic model to predict the cyclic stress-strain behavior of concrete subjected to uniaxial compressive loading is proposed. The model consists of rheological elements with random state variables with exponential distributions. The model has 3 parameters and can be calibrated by experimental data from only the monotonically increasing loading. It simulates well the main known characteristics of concrete response to cyclic loading, such as strain softening, path dependency, stiffness degradation, and the concept of envelope curve. The formulation is of the total strain type and all formulas are derived in closed form. The model is computationally efficient for predicting response to any arbitrary strain history. A flow chart for computer implementation is presented.