PSI - Issue 2_B

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com ienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Struc ural Integrity 2 (2016) 1143–1148 Available online at www.sciencedirect.com ScienceDire t 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 Gigacycle fatigue: non-local and scaling aspects of damage localization, crack initiation and propagation Oleg Naimark a * and Thierry Palin-Luc b a Institute of Continuous Media Mechanics UB RAS, 1 Acad.Korolev str., 614013 Perm Russia b Univ.Bordeaux, 12M, UMR5295, 351 Cours de la Liberation, 33405 Talence, France Abstract Progress in instrumentation in fatigue studies in the range 10 7 - 10 9 cycles revealed new paradigm: crack growth is not a main portion of life and initiation mechanisms are of primary importance with internal fatigue crack origin. Characteristic features of fatigue in this regime is strong evidence that Wohler-type S–N or Coffin–Manson diagrams can exhibit a second lower fatigue limit - multi-stage (duplex) fatigue life diagrams. An important finding in connection with these observations was that, in the transition from HCF to gigacycle regimes, the origins of fatigue failure changed from surface to interior ‘‘fish-eye’’ fracture. This experimental and theoretical study is focused on fatigue crack initiation and early slow crack growth as life-controlling factors of gigacycle fatigue. Nonlocal model of damage kinetics based on the description of collective behaviour of defects (slip bands, microshears, microcracks) allowed the interpretation of fatigue damage-failure transition as specific type of criticality in out-of-equilibrium system “solid with defects”. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: Gigacycle damage kinetics, self-similar solution, scaling of fracture surface 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Gigacycle fatigue: non-local and scaling aspects of damage localization, crack initiation and propagation Oleg Naimark a * and Thierry Palin-Luc b a Institute of Continuous Media Mechanics UB RAS, 1 Acad.Korolev str., 614013 Perm Russia b Univ.Bordeaux, 12M, UMR5295, 351 Cours de la Liberation, 33405 Talence, France Abstract Progress in instrumentati n in f tigue studies in the range 10 7 - 10 9 cycles reveale new par digm: cra k growth is not a main portion of life and initi ti mechanisms ar of primary importance with int rnal fatigue cr ck origin. Characterist c features of fatigue in this regime s strong evidence that Wohler-t pe S–N or Coffin–Ma son d agrams can exhibit a se ond low r fatigue limit - multi- tage (duplex) fatigue life diagrams. An important finding in co nection with these observ tions was that, in th transition from HCF to gigacycle regimes, the origi s of fa igue failure changed fr m surfac to int rior ‘‘fi h-eye’’ fracture. This experimental and theoreti al study is focused on fatigue crack initiatio and early slow crack g wth as life-controlling factors of gigacycle fatigue. Nonlocal model f damage kinetics b sed on the description of collective behaviour of defects (slip b nds, microshears, microcracks) allowed the interpretatio of fatigue damage-failure transition as specific type of criticality in out-of-equilibrium system “solid with d fects”. © 2016 The Authors. Published by Elsevier B.V. Peer-review under espons bility of the Scientific Committee of ECF21. Keywords: Gigacycle damage kinetics, self-similar solution, scaling of fracture surface Copyright © 2016 The Authors. Published by Elsevier B.V. This is an open access articl u der 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.

© 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Corresponding author. Tel.: +7-342-2378-312. E-mail address: naimark@icmm.ru Corresponding author. Tel.: +7-342-2378-312. E-mail address: naimark@icmm.ru

Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation. 1. Introduction HCF and VHCF are important fundamental and engineering problems for several areas o applications. High interest to VHCF is related du ing last ecades to the opportunity to reach numb r of cycl s 10 8 -10 10 for mater als a d constructions, for instance as- urbine motors, due to the usage of fine-grain superalloys and advanced technologies providing VHCF limit. However, traditional methods of t sting do not provid n estimate of f tigue 1. Introduction HCF and VHCF are important fundamental and engineering problems for several areas o applications. High interest to VHCF is related during last decades to the opportunity to reach number of cycles 10 8 -10 10 for materials and constructions, for instance gas-turbine motors, due to the usage of fine-grain superalloys and advanced technologies providing VHCF limit. However, traditional methods of testing do not provide an estimate of fatigue

* Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. 2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21.

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.2016.06.146