PSI - Issue 14

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 Structural Integrity 14 9 18–25 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000 – 000 Available online at www.sciencedirect.co i ir t 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. 2nd International Conference on Structural Integrity and Exhibition 2018 The effect of graphite size on hydrogen absorption and tensile properties of ferritic ductile cast iron Takuya Yoshimoto a *, Takashi Matsuo b,c and Tomohiro Ikeda d a Graduate School of Engineering, Fukuoka University, 8-19-1 Jonan-ku, Fukuoka, 814-0180, Japan b Department of Mechanical Engineering, Fukuoka University, 8-19-1 Jonan-ku, Fukuoka, 814-0180, Japan c Institute of Materials Science and Technology, Fukuoka University, 8-19-1 Jonan-ku, Fukuoka, 814-0180, Japan d Research & Development Center, HINODE, Ltd., Azaiwasaki, Miyaki-cho, Miyaki-gun, Saga, 849-0101, Japan Ductile cast iron (DCI) is one of prospective materials used for the hydrogen equipment because of low-cost, good workability and formability. The wide range of mechanical properties of DCI is obtained by controlling microstructural factors such as graphi e size, volume fraction of graphite, matrix structure and so on. Therefore, it is important to find out an optimal microstructural condition that is less susceptible to hydrogen embrittlement. In this study, the effects of graphite size on the hydrogen absorption capability and the hydrogen-induced ductility loss of ferritic DCI w re investigated. Several kinds of ferritic DCIs with a different graphite diameter of about 10 µm - 30 µm were used for the tensile test and the hydrogen content measurement. Hydrogen charging was performed prior to the tensile test by exposing a specimen to high pressure hydrogen gas. Then, the tensile test was performed in air at room temperature. The hydrogen content of a specimen was measured by a thermal desorption analyzer. It was found that the amount of hydrogen stored in DCI was dependent on the graphite size. As the graphite diameter increased, the hydrogen content sharply increased at a certain graphite diameter, and then it became nearly constant irrespective of increase in graphite diameter. In other words, there was the critical graphite diameter that significantly changed the hydrogen absorption capability. The ductility was decreased by hydrogen, and the hydrogen-induced ductility loss was dependent on the hydrogen content. Therefore, the hydrogen embrittlement of DCI became remarkable when the graphite size was larger than the critical value. 2nd International Conference on Structural Integrity and Exhibition 2018 ffect of graphite size on hydrogen absorption and tensile r rti s f f rriti til st ir akuya oshi oto a *, akashi Matsuo b,c and o ohiro Ikeda d a Graduate School of Engineering, Fukuoka University, 8-19-1 Jonan-ku, Fukuoka, 814-0180, Japan b Department of Mechanical Engineering, Fukuoka University, 8-19-1 Jonan-ku, Fukuoka, 814-0180, Japan c Institute of Materials Science and Technology, Fukuoka University, 8-19-1 Jonan-ku, Fukuoka, 814-0180, Japan d Research & Development Center, HINODE, Ltd., Azaiwasaki, Miyaki-cho, Miyaki-gun, Saga, 849-0101, Japan Abstract Ductile cast iron (DCI) is one of prospective materials used for the hydrogen equipment because of low-cost, good workability and formability. The wide range of mechanical properties of DCI is obtained by controlling microstructural factors such as graphite size, volume fraction of graphite, matrix structure and so on. Therefore, it is important to find out an optimal microstructural condition that is less susceptible to hydrogen embrittlement. In this study, the effects of graphite size on the hydrogen absorption capability and the hydrogen-induced ductility loss of ferritic DCI were investigated. Several kinds of ferritic DCIs with a different graphite diameter of about 10 µm - 30 µm were used for the tensile test and th hydrogen c tent measurement. Hydrogen charging was perfor ed prior to the tensile test by exposing a specimen to high pressure hydrogen gas. Then, the tensile test was performe in air at room temperature. The hydrogen content of a spe men was measured by a thermal des rption analyzer. It was found that the amount of hydrogen stor d in DCI wa dependent on the graphite size. As the graphite diameter incr ased, the hydrogen content sharply increased at a certain graphite diamet r, and then it became nearly constant irrespective of increase in graphite diameter. In other words, there was the critical graphite diameter that significantly changed the hydrogen absorption capability. The ductility was decreased by hydrogen, and the hydrogen-induced ductility loss was dependent on the hydrogen content. Therefore, the hydrogen embrittlement of DCI became remarkable when the graphite size was larger than the critical value. © 2018 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. © 2019 The Authors. Published y Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under responsibility of Peer-revi w u der responsibility of the SICE 2018 organizers. © 2018 The Authors. Published by Elsevier B.V. This is an open access articl under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation. Abstract

* Corresponding author. Tel.: +81-92-871-6631; fax: +81-92-865-6031. E-mail address: td170007@cis.fukuoka-u.ac.jp (T. Yoshimoto). * Corresponding author. Tel.: +81-92-871-6631; fax: +81-92-865-6031. E-mail address: td170007 cis.fukuoka-u.ac.jp (T. Yoshimoto).

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. 2452-3216  2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under responsibility of Peer-review under responsibility of the SICE 2018 organizers. 10.1016/j.prostr.2019.05.004 * Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452-3216 © 2018 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under responsibility of Peer-review under responsibility of the SICE 2018 organizers. 2452-3216 © 2018 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under responsibility of Peer-review under responsibility of the SICE 2018 organizers.