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 For nuclear safety, fracture evaluation of reactor pressure vessels (RPV) under neutron irradiation is key issue. Fracture toughness from a CT specimen is used as a material constant for fracture evaluation, but it is well known that it has a large constraint, which causes lower toughness than that of flawed structures, such as a RPV with a surface flaw. In ductile to brittle transition temperature (DBTT) region ferritic steel which is material of RPV has a large scatter and it becomes important to know the accurate scatter of an irradiated material because of less margin of RPV's integrity after a long term operation. In this paper to establish a more precise fracture evaluation method in DBTT region for an irradiated RPV with a postulated surface flaw, a coupled model of damage mechanics for ductile fracture and Beremin model for cleavage fracture was applied for correction of the effect of a small ductile growth on the stress-strain field. To confirm the validity of the method, as the first trial, fracture tests using CT specimens were performed in several temperature conditions. The temperature dependence of the parameters of Beremin models were investigated as well. Abstract For nuclear safety, fracture evaluation of reactor pressure vessels (RPV) under neutron irradiation is key issue. Fracture toughness from a CT specimen is used as a material constant for fracture evaluation, but it is well known that it has a large constraint, which causes lower toughness than that of flawed structures, such as a RPV with a surface flaw. In ductile to brittle transition temperature (DBTT) region ferritic steel which is material of RPV has a large scatter and it becomes important to know the accurate scatter of an irradiated material because of less margin of RPV's integrity after a long term operation. In this paper to establish a more precise fracture evaluation method in DBTT region for an irradiated RPV with a postulated surface flaw, a coupled model of damage mechanics for ductile fracture and Beremin model for cleavage fracture was applied for correction of the effect of a small ductile growth on the stress-strain field. To confirm the validity of the method, as the first trial, fracture tests using CT specimens were performed in several temperature conditions. The temperature dependence of the parameters of Beremin models were investigated as well.