Abstract :
Several standard fatigue testing methods are used to determine the fatigue stress-lifeprediction model (S-N curve) and the endurance limit of Reinforced Concrete (RC) beams, includingthe application of constant cyclic tension-tension loads at di erent stress or strain ranges. The standardfatigue testing methods are time-consuming and expensive to perform, as a large number of specimensis needed to obtain valid results. The purpose of this paper is to examine a fatigue stress-life predicationmodel of RC beams that are developed with an accelerated fatigue approach. This approach isbased on the hypothesis of linear accumulative damage of the Palmgren–Miner rule, whereby theapplied cyclic load range is linearly increased with respect to the number of cycles until the specimenfails. A three-dimensional RC beam was modeled and validated using ANSYS software. Numericalsimulations were performed for the RC beam under linearly increased cyclic loading with di erentinitial loading conditions. A fatigue stress-life model was developed that was based on the analyzeddata of three specimens. The accelerated fatigue approach has a higher rate of damage accumulationsthan the standard testing approach. All of the analyzed specimens failed due to an unstable crackingof concrete. The developed fatigue stress-life model fits the upper 95% prediction band of RC beamsthat were tested under constant amplitude cyclic loading.
