During their operation, modern aircraft engine components are subjected to increasingly demanding operating conditions, especially the high pressure turbine (HPT) blades. Such conditions cause these parts to undergo different types of time-dependent degradation, one of which is creep. A model using the finite element method (FEM) was developed, in order to be able to predict the creep behaviour of HPT blades. Flight data records (FDR) for a specific aircraft, provided by a commercial aviation

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... mpany, were used to obtain thermal and mechanical data for three different flight cycles. In order to create the 3D model needed for the FEM analysis, a HPT blade scrap was scanned, and its chemical composition and material properties were obtained. The data that was gathered was fed into the FEM model and different simulations were run, first with a simplified 3D rectangular block shape, in order to better establish the model, and then with the real 3D mesh obtained from the blade scrap. The overall expected behaviour in terms of displacement was observed, in particular at the trailing edge of the blade. Therefore such a model can be useful in the goal of predicting turbine blade life, given a set of FDR data. Abstract Cortical bone contributes to about 80% of the weight of the human skeleton. Along its other properties, cortical bone presents a high resistance to fracture propagation. With this paper the authors aim to model this material using the Extended Finite Element Method (X-FEM) and to understand the mechanism that allow this material to have such a property. A numerical model was developed, considering a biomimetic bone like composite material, modelling the primary anatomical and functional unit of cortical bone, the osteon, as a fiber, the interstitial lamellae as the matrix, and the cement line between them. Different properties were considered for all the above mention materials, and their influence on the micro-crack propagation was studied. The cracks introduced and their geometry allowed the authors to understand why the cracks are arresting their propagation, and why is this material so resistant to crack propagation. The results are presented using the calculated stress intensity factors, for different material and geometries, and also using several brittle fracture crack propagation examples calculated using X-FEM. Abstract Cortical bone contributes to about 80% of the weight of the human skeleton. Along its other properties, cortical bone presents a high resistance to fracture propagation. With this paper the authors aim to model this material using the Extended Finite Element Method (X-FEM) and to understand the mechanism that allow this material to have such a property. A numerical model was developed, considering a biomimetic bone like composite material, modelling the primary anatomical and functional unit of cortical bone, the osteon, as a fiber, the interstitial lamellae as the matrix, and the cement line between them. Different properties were considered for all the above mention materials, and their influence on the micro-crack propagation was studied. The cracks introduced and their geometry allowed the authors to understand why the cracks are arresting their propagation, and why is this material so resistant to crack propagation. The results are presented using the calculated stress intensity factors, for different material and geometries, and also using several brittle fracture crack propagation examples calculated using X-FEM.