PSI - Issue 2_A

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com ScienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Struc ural Integrity 2 (2016) 3026–3039 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2016) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2016) 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. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Determination of crack initiation and crack growth stress-life curves by fracture mechanics experiments and statistical analysis Stefan Kolitsch a,b *, Hans-Peter Gänser a , Reinhard Pippan b a Materials Center Leoben Forschung GmbH, Roseggerstraße 17, A-8700 Leoben b Erich Schmid Institute of Materials Science, Austrian Academy of Sciences, Jahnstraße 12, A-8700 Leoben It is well known that the fatigue lifetime of a notched component consists of the crack initiation lifetime (crack size equal to the characteristic microstructure size) and the crack growth lifetime. The crack growth lifetime is easily calculated if the initial crack size is known. A much more difficult task is to define a suitable initial crack size and to determine the initiation lifetime of such a crack. In the present contribution, a method is proposed to determine the crack initiation as well as the crack growth lifetime within a conventional f acture mechanics setup. To his purpose, singl edge notched bending (SENB) specimens were manufactured with two different notch geometries. For measuring the crack length, the direct current po ential dr p (DCPD) technique was use . The DCPD results are not only us d for crack growth assessment, but also for determining th point – or range, respectively – of crack initiation. By a statistical assessment f DCPD measurements at different load stress levels, it is possible to determine crack initiation and crack growth stress-life (S/N) curves, and in particular to assess the influence of the notch geometry on the crack initiation lifetime. The lower statistical tolerance limits of these curves may be used as criteria for mechanical design and determination of inspection intervals. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: fatigue, notch, NASGRO equation, crack initiation, crack growth 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Determination of crack initiation and crack growth stress-life curves by fracture mechanics experiments and statistical analysis Stefan Kolitsch a,b *, Hans-Peter Gänser a , Reinhard Pippan b a Materials Center Leoben Forschung GmbH, Roseggerstraße 17, A-8700 Leoben b Erich Schmid Institute of Materials Science, A strian Academy of Scienc s, Jahnstraße 12, A-8700 Leoben Abstract It is well known that the fatigue lifetime of a notched component consists of the crack initiation lifetime (crack size equal to the characteristic microstructure size) and the cr ck growth lifetim . The crack growth lifet me is easily calculated if th initi l crack size is known. A much mo difficult task is to define a suitabl initial crack size and to determine the initi tion lifetime of such a crack. In the present contribution, a method is proposed to determine the crack initiation as well as the crack growth lifetime within a conv ntional fractu e mechanics setup. To this purp se, single edg not hed bendi g (SENB) sp cimens were manufactured with two different notch geometries. For measuring the crack le gth, the direct current pot ntial drop (DCPD) tech ique was used. Th DCPD resul s are not only sed for crack rowth ssessment, but lso for determini g th p int – or range, respectively – of crack initiation. By a statistical assessment of DCPD measurements at different load stress levels, it is possible to determine crack initiation and crack growth stress-life (S/N) curves, and in particular to assess the influ nce of the notch geomet y on the crack initiation lifetime. The low r statistical tole ance limits of these curves may be used as criteria for me anical design and determina on of inspection intervals. © 2016 The Authors. Published by Elsevier B.V. Peer-review under respons bility of the Scientific Committee of ECF21. Keywords: fatigue, notch, NASGRO equation, crack initiation, crack growth Copyright © 2016 The Authors. Published by El evier B.V. This is an open access le under the CC BY-NC-ND lic nse (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of the Scientific Committee of ECF21. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Abstract

Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation.

* Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review un r responsibil ty of the Scientific Committee of ECF21. 2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer review under r sponsibility of the Scientific Committee of ECF21. * Corresponding author. Tel.: +43-3842-45922-516; fax: +43-3842-45922-516. E-mail address: stefan.kolitsch@mcl.at * Corresponding author. Tel.: +43-3842-45922-516; fax: +43-3842-45922-516. E-mail ad ress: s efan.ko itsch@mcl.at

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Copyright © 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ). Peer review under responsibility of the Scientific Committee of ECF21. 10.1016/j.prostr.2016.06.379