(YIP 11) Concurrent Structural Fatigue Damage Prognosis Under Uncertainty

In this study, a novel structural fatigue prognosis method is developed to provide prompt, informed fatigue damage predictions of the structures based on strain gauge measurements at remote locations. The method is based on the structural responses reconstruction at the hot spots and a mechanism-based fatigue crack growth formulation. The structural responses measured from usage monitoring system or sensors at available locations are decomposed into modal responses using empirical mode decomposition. Transformation equations based on finite element modeling are derived to extrapolate the modal responses from the measured locations to critical locations where direct sensor measurements are not available. The evolution of fatigue damage within structures can then be performed using the reconstructed stress responses. A numerical two-span beam example is used to demonstrate the overall reconstruction method. Following this, a practical structure scale problem is provided to validate the effectiveness and the accuracy of the proposed method. Fatigue damage prognosis using the reconstructed stresses from remote strain gauge measurement data is also demonstrated with detailed error analysis.