Initial fatigue quality confidence-interval approach for determination of inspection intervals

An approach is proposed for the determination of the inspection interval of metallic aerospace components ; it makes use of the Initial Fatigue Quality Model proposed by the U.S. Air Force. Once the structure has been qualified through the latter model, an upper and a lower bound for the inspection time are obtained. Such bounds are derived on the basis of a statistical procedure based on the knowledge of confidence intervals. Tables of general applicability have been obtained through Monte Carlo simulations to allow the determination of the interval in which the inspection time should lie. An example problem is discussed to show an application of the proposed method.