FAILURE ANALYSIS OF INITIALLY CRACKED CONCRETE STRUCTURES

Fracture mechanics is very often employed in analyses of cracked struc tural components. We present here another technique that is based on t he equivalence between a crack, its process tom, and a distribution of damage. It is a simplified method aimed at approximating the distribu tion of damage around an existing crack. This approximation is based o n the analysis of localization with a nonlocal damage model. Finite-el ement calculations on a compact tension concrete specimen for several initial crack lengths are presented and compared with experiments. The method is shown to yield errors less than 20% on the prediction of th e load reduction factor as a function of the initial crack length. The method is also extended to the prediction of the response of fiber-re inforced components with initial damage. The response of cracked fiber -reinforced concrete (FRC) beams is computed and compared with the res ults of original experiments, where the loading conditions that create d the initial crack are different from those leading to failure.