PSI - Issue 13

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 13 (2018) 1026–1 31 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Int grity 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 Re-examination of fatigue crack propagation mechanism under cyclic Mode II loading Shigeru Hamada a *, Taro Suemasu b , Motomichi Koyama a , Masaharu U da c and Hiroshi No uchi a a Faculty of Engineering, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan b Graduate School of Engineering, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan c Yawata R & D Lab., Nippon Steel & Sumitomo Metal Co., 1-1 Tobihatacho Tobata-ku, Kitakyushu 804-8501, Japan Abstract The essence of rolling contact fatigue is the so- called “Mode II fatigue crack propagation.” However, its understanding has not progressed as much as that of Mode I. We think that this cause is the name: “Mode II fatigue crack propagation.” Originally, Modes I and II represented the loading modes for still cracks in fracture mechanics, and not the fatigue crack propagation mechanism. There are many cases where the knowledge of fatigue crack propagation under Mode I loading is applied to that under Mode II loading without consideration. Moreover, in the rolling contact fatigue region where the fatigue crack propagates under Mode II loading, a large plastic deformation is caused by the rolling contact load. Therefore, it is n cessary for the test method to reproduce the effects of an actual machine to test materials that exhibit large plastic def rmation. Ther fore, in this study, we aim to classify the fatigue crack propagation phenome a, r gardl ss of Mode I and II loadings, and re-examine the mechanisms. To that end, we d veloped a novel test method that enables pure Mode II lo ding. We used a micro-thin film disc as a specimen, making it possible to cut out and test a part subjected to large plastic deformation from the actual machine. By observations f the crystall graphic structure before the fatigue test and the successive observation of fatigue crack propagation behavior, e pr pose a crack propagation mec anism, namely, damage accumulation type fatigue crack propagation under Mode II loading, which is different from the opening type fatigue crack propagation. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. ECF22 - Loading and Environmental effects on Structural Integrity Re-examination of fatigue crack propagation mechanism under cyclic Mode II loading Shigeru Hamada a *, Taro Suemasu b , Motomichi Koyama a , Masaharu Ueda c and Hiroshi Noguchi a a Faculty of Engineering, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan b Graduate School of Engineering, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan c Yawata R & D Lab., Nippo Ste l & Sumitom Metal Co., 1-1 Tobihatacho Tobata-ku, Kitakyushu 804-8501, Japan Abstract The essence of rolling c ntact f t gue is th so- called “Mod II fatigue crack propagation.” However, its understanding has n t progre sed as much as tha of Mode I. We think that this cause is th name: “Mode II fatigue crack propagation.” Originally, M des I and II repre ented the l ading modes for still crack in fracture mechanics, and not the fatigue crack propagation mechanism. Ther a many cases where the knowledge of fatigue crack propagation under Mode I loading is applied to that under Mode II loading without consid ration. Moreover, in the roll ng contact fatigue regio where the fatigue crack propagates , a large plastic deformation is caused by the rolling contact load. Therefor , it is necessary for the test m thod to reproduce t e effects of an ctual machine to test materials that exhibit large plastic deformat on. Therefo e, in t is study, we aim to classify t e fatigue cr ck propag tio phenomena, egardless of Mode I and II loadings, and re-examine the mechanisms. To hat end, we developed novel test method that enabl s pure Mode II loadi g. We used a micro thin f lm disc as a specimen, m king it possibl to cut out and test a part subjected to a la ge plastic deformation from the actual machine. By observations of the crystallographic struct re before the fatigue test and the successive observation f fatigue crack propagation b havi r, we propose crack propagation mechanism, namely, damage acc mulat on typ f tigue crack propagation under Mod II loading, which is different from the opening type fatigu crack propagation. © 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. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: Mode II; Fracture mechanics; Damage accumulation; Fatigue crack propagation phenomenon; Fatigue crack propagation mechanism Keywords: Mode II; Fracture mechanics; Damage accumulation; Fatigue crack propagation phenomenon; Fatigue crack propagation mechanism

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 © 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.: +81-92-802-3061; fax: +81-92-802-0001. E-mail address: hamada@mech.kyushu-u.ac.jp * Corresponding author. Tel.: +81-92-802-3061; fax: +81-92-802-0001. E-mail ad ress: hamada@mech.kyushu u.ac.jp

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.2018.12.191