PSI - Issue 13

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at www.sciencedire t.com ScienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structural Integrity 13 (2018) 1032–1 36 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural I tegrity 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. ECF22 - Loading and Environmental effects on Structural Integrity Effect of Si on temperature dependence of non-propagation limit of small fatigue crack in a Fe-C alloy Kohei Kishida a *, Motomichi Koyama a , Nobuyuki Yoshimura b , Eisaku Sakurada c , Tatsuo Yokoi d , Kohsaku Ushioda e , Kaneaki Tsuzaki a , H roshi Noguchi a a Faculty of Engineering, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka-shi, Fukuoka 819-0395, Japan b Nippon Steel & Sumitomo Metal Corporation, 20-1 Shintomi, Futtsu, Chiba 293-8511, Japan c Nippon Steel & Sumitomo Metal Corporation, 5-3 Tokai, Tokai, Aichi 476-8686, Japan d Nippon Steel & Sumitomo Metal Corporation, 1 Oaza-Nishinosu,Oita, Oit 970-0922, Jap n e Nippon Steel & Sumikin Research Institute Corporation, Kokusai Bldg., 3-1-1 Marunouchi, Chiyoda, Tokyo 100-0005, Japan Abstract Dynamic strain aging improves the non-propagation limit of a fatigue crack in ferritic iron alloys containing supersaturated carbon. However, upon increasing the test temperature, the non-propagation limit of the fatigue crack decreases owing to carbide precipitation. In this study, we present a guideline to improve high-temperature fatigue resistance in ferritic steels containing supersaturated carbon via Si addition that suppresses carbide formation. Compared with an Fe-0.017C binary alloy, an Fe- 0.016C-1.0Si alloy shows higher tensile strength at 293 and 433 K. The Si addition increased the fatigue limit at both temperatures as compared with that of the Fe – C binary alloy. The higher fatigue limit than that of the binary alloy at 293 K originated from the solid solution strengthening of Si, whereas the improved fatigue limit in Fe-0.016C-1.0Si at 433 K was attributed not only to the solution hardening, but also to the suppression of carbide formation at 433 K. With an increase in the temperature from 293 to 433 K, the reduction in the fatigue limit of the Fe-0.017C alloy was 65 MPa, while that for the Fe-0.016- 1Si alloy was only 40 MPa. These results indicated that the robustness against temperature can be improved by the addition of Si. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. © 2018 Th Authors. Published by Elsevier B.V. Peer-review und r responsibility f the ECF22 organizers. ECF22 - Loading and Environmental effects on Structural Integrity Effect of Si on temperature dependence of non-propagation limit of small fatigue crack in a Fe-C alloy Kohei Kishida a *, Motomichi Koyama a , Nobuyuki Yoshimura b , Eisaku Sakurada c , Tatsuo Yokoi d , Kohsaku Ushioda e , Kaneaki Tsuzaki a , Hiroshi Noguchi a a Faculty of Engineering, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka-shi, Fukuoka 819-0395, Japan b Nippon St el & Sumitomo Metal Corporati n, 20-1 Shintomi, Futtsu, C iba 293-8511, Japan c Nippon Steel & Sumitomo Metal Corporation, 5-3 Tokai, Tokai, Aichi 476-86 6, Jap n d Nippon Steel & Sumitom Metal Corporation, 1 Oaza-Nishin su,Oita, Oita 970-0922, J pan e Ni pon Steel & Sumik n Research Institute Corporation, K kusai Bldg., 3-1-1 Marunouchi, Chiyoda, T kyo 100-0 05, Japan Abstract Dynamic strain aging improves the non-propagation limit of a fatigue crack in ferritic iron alloys containing supersaturated carbon. However, upon ncreasing t test tem er ure, the non-propa ation limit of the fat gue crack decre ses owing to ca bide precipitati n. In this study, we pres n a guideline to impr ve high-temperature a igue resistance in ferritic steels c nt in ng supersaturated carbon via Si additio that suppresses carbid formation. Compared with an Fe-0.017C b nary alloy, an Fe 0.016C-1.0Si alloy shows higher tensile strength at 293 and 433 K. The Si ad ition increased the fatigue limit at both temperatures as compared w th tha of the F – C binary alloy. The higher fatigue limit tha that of t binary alloy at 293 K originated from the solid solution strengthening of Si, whereas the mproved fatigue limit in Fe-0.016C-1.0Si at 433 K was attributed not only to the solution ha dening, but also to the suppression of carbide formation at 433 K. With an increase in the temperature fr m 293 o 433 K, the re uction in he fatigue limit of the Fe-0.017C all y w s 65 MPa, while that for the Fe-0.016 1Si alloy was nly 40 MPa. These results indicated th t th robustness against temperature can be improved by he addition of Si. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers.

© 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: ferritic steel; dynamic strain aging; dynamic precipitation; high temperature; small fatigue crack growth; Keywords: ferritic steel; dynamic strain aging; dynamic precipitation; high temperature; small fatigue crack growth;

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

* Corresponding author. Tel.: +81-92-802-3141. E-mail address: 2te18659p@s.kyushu-u.ac.jp * Corresponding author. Tel.: +81-92-802-3141. E-mail ad ress: 2te18659p@s.kyushu-u.ac.jp

2452-3216 © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. 2452-3216 © 2018 The Authors. Published by Elsevier B.V. Peer review under r sponsibility of the ECF22 o ganizers.

* 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 PCF 2016.

2452-3216  2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. 10.1016/j.prostr.2018.12.192