Fatigue behaviour is most commonly evaluated in uni-axial cyclic stress tests using standardiseddog-bone samples. When components are sharply bent into shape and subjected to cyclic loading, thefatigue damage will accumulate at the inside of the bend. This paper reports on an experimentalinvestigation about the feasibility of infrared thermographic techniques to monitor fatigue damage initiationand accumulation. By monitoring spectral components of the thermal response, the fatigue limit, the onsetof crack initiation and the ratio of initiation to propagation lifetime can all be determined. Also the effect ofsurface treatments on initiation properties is investigated. Most results are consistent with expectedbehaviour based on a previous study, indicating that thermographic techniques have a greater sensitivityand can be used to reduce the number of samples and time required for fatigue characterisation.
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