PSI - Issue 13

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ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com Sci ceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structural Integrity 13 (2018) 1154–1158 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000 – 000 ScienceDirect 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. ECF22 - Loading and Environmental Effects on Structural Integrity Proposal and verification of novel fatigue crack propagation simulation method by finite element method. Temma Sano a , Daisuke Sasaki b , Motomichi Koyama c , Shigeru Hamada c , Hi oshi Noguchi c a Graduate School of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, Fukuoka 819-0395, Japan b National Institute of Technology, Kurume College, 1-1-1 Komorino, Fukuoka, Fukuoka 830-8555, Japan c Faculty of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, Fukuoka 819-0395, Japan In this paper, we propose and verify a novel method to simulate crack propagation without propagating a crack by finite element method. We propose this method for elastoplastic analysis coupled with convection-diffusion. In the previous study, we succeeded in performing elastoplastic analysis coupled with convection-diffusion of hydrogen for a material with a crack under tensile loading. This research extends the successful method to fatigue crack propagation. In convection-diffusion analysis, in order to simulate the invasion and release of ele ents through the free surface, the crack tip is expressed by using a notch with a sufficiently small radius. Therefore, the node release method conventionally used to simulate crack propagation cannot be applied. Hence, instead of crack propagation based on an analytical model, we propose a novel method that can reproduce the influence of the vicinity of the crack tip on a crack. We moved the stress field near the crack tip in the direction opposite to that of crack propagation by an amount corresponding to the crack propagation length. When we extend the previous method to fatigue crack propagation simulation, we must consider the difference in strain due to loading and unloading. This problem was solved by considering the strain due to loading as a displacement. Instead of moving the strain due to loading, we moved the displacement. First, we performed a simple tensile load analysis on the model and output the displacement of all the nodes of the model at maximum load. Then, the displaceme t was moved in the direction opposite to that of crack propagation. Finally, the stress field was reproduced by forcibly moving all the nodes by the displacement amount. The strain due to unloading was reproduced by removing the displacement. Furthermore, we verified the equivalence of the crack propagation simulation and the proposed method. ECF22 - Loading and Environmental Effects on Structural Integrity Proposal and verification of novel fatigue crack propagation simulation method by finite elem nt method. Temma Sano a , Daisuke Sasaki b , Motomichi Koyama c , Shigeru Hamada c , Hiroshi Noguchi c a Graduate School of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, Fukuoka 819-0395, Japan b National Institute of Technology, Kurume College, 1-1-1 Komorino, Fukuoka, Fukuoka 830-8555, Japan c F culty of Engineeri g, Kyushu Univers ty, 744 Motooka, Nishi-ku, Fukuoka, Fukuoka 819-03 5, Japan Abstract In this paper, we prop se and verify a nov l method to simulate crack propagation without propagating a cr ck by finite element method. We propose this method for elastoplastic analysis coupled with convection-diffusion. In the previous study, we succeeded in performing elasto lastic analysis coupled with convection-diffusion of hydro en for a material with a crack under tensil loading. This research extends the successful meth d to fatigue crack propagation. I convection-diffusion analysis, in order to simulat the i vasion and release of element thr gh the free surface, the crack tip is expressed by using a notch with a sufficiently small radius. Therefore, the node rel a e method conventionally used to simulate crack propagation ca not be applied. Hence, instead of crack propagation based on an analytical model, we propose a novel method that can reproduce the influence of the vici it of the crack tip on a crack. We moved the stress field near the crack tip in the direction opposite to that of crack propagation by an amount orres onding t the crack propagation length. When we extend the previous method to fatigue crack propagation simulation, we must consider the diff rence in strain due to loading and unloading. This problem was solved by considering the strain due to loading as a displac ment. Inste d of moving the strain due to loading, we mov d the displacement. First, we perfor ed a simpl ten ile load analysis on th model an output the displacement of all the nodes of the model at maximum load. Then, the displacement was mov d in the irection opposite to that of crack propagation. Finally, the str ss field was reproduced by forcibly m ing all th nodes by t displacement amount. The strain due to unloadi g was r p oduced by removing the displacement. Furthermore, e v rifi the equivalence f the c ack propagation simul tion and the proposed method. Abstract

© 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. © 2018 Th A thors. Published b Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation. © 2018 The Authors. Published by Elsevi r B.V. Peer-review under responsibility of the ECF22 organizers. K ywords: Finite elem nt method; Hydrog n diffusion; Fat gue; Crack propagation

Keywords: Finite element method; Hydrogen diffusion; Fatigue; Crack propagation

* 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 responsibility of the ECF22 organizers.

2452-3216  2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. 10.1016/j.prostr.2018.12.240

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