PSI- Issue 9

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at www.sciencedire t.com cienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structu al Integrity 9 (2018) 151–158 Available online at www.sciencedirect.com ScienceDirect Structural I tegrity Procedia 00 (2018) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000–000

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XV Portuguese Conference on Fracture, PCF 2016, 10-12 February 2016, Paço de Arcos, Portugal Thermo-mechanical modeling of a high pressure turbine blade of an airplane gas turbine engine P. Brandão a , V. Infante b , A.M. Deus c * a Department of Mechanical Engineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa, Portugal b IDMEC, Department of Mechanical Engineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa, Portugal c CeFEMA, Department of Mechanical Engineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa, Portugal Abstract 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 company, 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. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. IGF Workshop “Fracture and Structural Integrity” Evaluating the specific heat loss in severely notched stainless steel specimens for fatigue strength analyses Daniele Rigon*, Mauro Ricotta, Giovanni Meneghetti University of Padova, Department of Industrial Engineering, via Venezia 1 – 35131 Padova, Italy Abstract In the last years, a large amount of fatigue test results from plain and bluntly notched specimens made of AISI 304L stainless steel were synthetized in a single scatter band adopting the specific heat loss per cycle (Q) as a damage parameter. During a fatigue test, the Q parameter can be evaluated measuring the cooling gradient at a point of the specimens after having suddenly stopped the fatigue test. This measurement can be done by usin thermocouples in the case of plain or notched material; however, due to the high stress concentration at the tip of severely notched components analysed in the present paper, an infrared camera achieving a much improved spatial resolution was adopted. A data processing technique is presented to investigate the heat energy distribution close to the notch tip of hot-rolled AISI 304L stainless steel specimens, having notch tip radii equal to 3, 1 and 0.5 mm and subjected to constant amplitude cyclic loads. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. Keywords: Energy Distribution; Fatigue; Notch Effect 1. Introduction By exploiting the surface temperature increment of the material subjected to cyclic stress, in literature some methods are reported for t e rapid stimation of fatigue limit in metallic materials and components (Dengel and Harig (1980), Luong (1995), La Rosa and Risitano (2000), Curà et al. (2005)), the detection and propagation of damage in metal materials and composites in (Reifsnider and Williams (1974), Plekhov et al. (2005), Ummenhofer IGF Workshop “Fracture and Structural Integrity” Evaluating the specific heat loss in severely notched stainless steel specimens for fatigue strength analyses Daniele Rigon*, Mauro Ricotta, Giovanni Meneghetti University of Padova, Department of Industrial Engineering, via Venezia 1 – 35131 Padova, Italy Abstract In the last years, a large amount of fatigue test results from plain and bluntly notched specimens made of AISI 304L stainless steel were synthetized in a single scatter band adopting the specific heat loss per cycle (Q) as a damage parameter. During a fatigue test, the Q parameter can be evaluated measuring the cooling gradient at a poi t of the specimens after having suddenly stopped the fatigu test. This measurement can be done by usi g t rm couples in the case of plain or notched material; how ver, du to the high stress concentration at the tip of severely notched components analysed in the pr sent paper, an infrared camera a hieving a much improved spatial resolution was adopted. A data proc ssing technique is presented to investig te the heat energy distribution close to the notch tip of hot-rolled AISI 304L stainless steel specimens, having notch tip radii equal to 3, 1 and 0.5 mm and subjected t co st nt amplitude cy lic l ads. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. Keywords: Energy Distribution; Fatigue; Notch Effect 1. Introduction By exploiting the s rfac temperatu e increment of the material subjected to cyclic stress, in literature some methods are repo t d for the rapid estimation f fatigue limit in metallic materials and components (Dengel and Harig (1980), Luong (1995), La Rosa and Risitano (2000), Curà et al. (2005)), the detection and propagation of damage in metal materials and composites in (Reifsnider and Williams (1974), Plekhov et al. (2005), Ummenhofer © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation.

* Corresponding author. Tel.: +39-049-827-6828. E-mail address: daniele.rigon.1@phd.unipd.it * Correspon ing author. Tel.: +39-049-827-6828. E-mail address: daniele.rigon.1@phd.unipd.it

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. 2452-3216  2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. 10.1016/j.prostr.2018.06.023 * Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452 3216 © 2018 Th Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. 2452-3216 © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo.