PSI - Issue 2_A

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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) 1199–12 6 ScienceDirect Structural Integrity Procedia 00 (2016) 000–000 Structural Integrity Procedia 00 (2016) 000–000 Available online at www.sciencedirect.com ScienceDirect

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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 A probabilistic model on crack initiation modes of metallic materials in very high cycle fatigue Akiyoshi Nakagawa a , Tatsuo Sakai b *, D. Gary Harlow c , Noriyasu Oguma d , Yuki Nakamura e , Akira Ueno f , Shoichi Kikuchi g , Akiyoshi Sakaida h a Industrial Products Company, Hitachi, Ltd., 3-18 Nakanoshima 2-chome, Kita-ku, Osaka, 530-0005 Japan b Research Organization of Science and Engineering, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga, 525-8577 Japan c Dept. of Mechanical Engi eering and Mechanics, Lehigh U versity, 19 Memorial Drive West, Bethlehem, PA 8015 USA d Faculty of Engineering, University of Toyama, 3190 Gofuku, Toyama, 930-8555 Japan e National Institute of Technology, Toyota College, 2-1 Eisei-cho, Toyota, Aichi, 471-8525 Japan f College of Science and Engineering, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga, 525-8577 Japan g Faculty of Engineering, Kobe University, 1-1 Rokko-dai, Nada, Kobe, Hyogo, 657-8501 Japan h National Institute of Technology, Akashi College, Uozumi, Akashi, Hyogo, 674-8501 In the very high cycle regime, the duplex S-N property consisting of S-N curve for surface-initiated fracture and that for interior-initiated fracture was often reported for high strength steels. However, recent studies show us the fact that the surface initiated fracture can be sometimes observed even at low stress levels in the very high cycle regime. In the case of interior fracture mode, a non-metallic inclusion is usually found at the center of th fish-eye. If we suppose that such inclusions are distributed at random inside the ma erial space, a certain number of inclusions would be located within the thin surf c layer of the specimen. In such c ses, the fatigue crack can take place within the surfa e layer giving the surface-initiate fractu even in the very high cycl regime. In the present work, the authors have attempted to construct a probabilistic model on the overall feature of these crack initiation modes in the very high cycle regime under the loading type of rotating bending. Thus, based on the distribution prope ty of the inclusions inside the material, the appearing probability of the surface-initiated fracture and the distribution characteristics of the fatigue strength at N =10 9 cycles were well explained by the present model. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy A probabilistic model on crack initiation modes of metallic materials in very high cycle fatigue Akiyoshi Nakagawa a , Tatsuo Sakai b *, D. Gary Harlow c , Noriyasu Oguma d , Yuki Nakamura e , Akira Ueno f , Shoichi Kikuchi g , Akiyoshi Sakaida h a Industrial Products Company, Hitachi, Ltd., 3-18 Nakanoshima 2-chome, Kita-ku, Osaka, 530-0005 Japan b Research Organization of Science and Engineering, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga, 525-8577 Japan c Dept. of Mechanical Engineering and Mechanics, Lehigh University, 19 Memorial Drive West, Bethlehem, PA 18015 USA d Faculty of Engi eering, Un versity of Toy ma, 3190 Gofuku, Toyama, 930-8555 Japan e Natio al Institut of Tech ology, Toyota College, 2-1 Eisei-cho, Toyota, Aichi, 471-8525 J pan f College of Scien e and i eeri , Ritsumeikan University, -1-1 Nojihigashi, Kusatsu, Shiga, 525-8577 Japan g Faculty of Engineering, Kobe University, 1-1 Rokko-dai, Nada, Kobe, Hyogo, 657-8501 Japan h National Institute of Technology, Akashi College, Uozumi, Akashi, Hyogo, 674-8501 Abstract In the very high cycle regime, the duplex S-N property consisting of S-N curve for surface-initiated fracture and that for interior-initiated fracture was often reported for high strength steels. However, recent studies show us the fact that the surface initiated fracture can be someti es observed even at low stress levels in the ve y high cycle regime. In the case of interi fracture mode, a non-metallic inclusion is usually found at the center of the fish-eye. If we suppose t at such inclusions are distributed at random inside the aterial space, a certain number of inclusions would be lo ated within the thin surface lay f the speci en. In such cases, the fatigue crack c n take place within the surface layer giving the surfac -initiated fracture even in the very high cycle regime. In the p esent work, the authors have attempted to construct a probabilistic model on the ov rall featur of these cra k initiation modes in the very high cy le regime u de th oading type of rotating bending. Thus, bas d o distribution property of the inclusions inside the material, the appe ring probability of the surface-initiate fractur and the dis ribution characteristics of the fatigue strength at N =10 9 ycl s were well explained by th present model. Keywords: Probabilistic model; duplex S-N curves; very high cycle fatigue; metallic materials; crack initiation modes; inclusion ; 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. © 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. Abstract Keywords: Probabilistic model; duplex S-N curves; very high cycle fatigue; metallic materials; crack initiation modes; inclusion ;

* 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. * Corresponding author. Tel.:+81-77-561-2745; fax:+81-77-561-2745. E-mail address: sakai@se.ritsumei.ac.jp 2452 3216 © 2016 The Autho s. Publ shed by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. * Corresponding author. Tel.:+81-77-561-2745; fax:+81-77-561-2745. E-mail address: sakai@se.ritsumei.ac.jp

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.2016.06.153