PSI - Issue 13

ScienceDirect Available online at www.sciencedirect.com Available online at www.sciencedire t.com ienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structural Integrity 13 (2018) 1291–1296 Available online at www.sciencedirect.com ScienceDirect StructuralIntegrity Procedia 00 (2018) 000 – 000 Available online at www.sciencedirect.com ScienceDirect StructuralIntegrity 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 Main mechanical factors affecting creep strain at crack tip of stress corrosion cracking in full life cycle Yinghao Cui, He Xue*, Shuai Wang, Xiaoyan Gong, Jianlong Zhang School of Mechanical Engineering, Xi'an University of Science and Technology, Xi'an 710054, China Stress Corrosion Cracking (SCC) is a failure mechanism that is caused by environment, susceptible material and tensile strain at crack tip. The mechanical state at crack tip is one of the main factors affecting stress corrosion crack propagation rate in structural materials of nuclear power plants. To understand the effect of mechanical factor on creep strain on SCC crack growth rate in the light water reactor environments, the creep strain at crack tip in full life cycle is studied by elastic-plastic finite element method (EPFEM) in this paper. Study results indicate that it is suitable to use the creep strain in front of crack tip as a mechanical factor of SCC behaviors, and also show that wedging stress is the main mechanical factor affecting creep strain in micro crack stage, while external load are gradually becoming the main mechanical factor in long crack stage. Crack propagation rate is very slow in micro crack stage, and it will expand rapidly under the combined effect of residual stress and working load if there is an initial crack l. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: Full life cycle; Elastic-plastic FEM simulation; Creep strain; Nickel-base alloy 600 1. Introduction Stress corrosion cracking (SCC) is a failure mechanism that is caused by environment, susceptible material and tensile strain of nuclear power structural materials under high temperature and high pressure aqueous environments [1-3]. Because many stainless steel components are subject to SCC in light water reactors, many efforts have been made to understand the underlying mechanism of SCC and to develop predictive model for lifetime estimation [4]. ECF22 - Loading and Environmental effects on Structural Integrity Main mechanical factors affecting creep strain at crack tip of stress corr sion c acking in full life cycle Yinghao Cui, He Xue*, Shuai Wang, Xiaoyan Gong, Jianlong Zhang School of Mechanical Engineering, Xi'an University of Science and Technology, Xi'an 710054, China Abstract Stress Corrosion Cracking (SCC) is a failure mechanism that is caused by environment, susceptible material and tensile strain at crack tip. The mechanical state at crack tip is one of the main factors affecting stress corrosion crack propag tion r te in structu l mate ials of nuclear power plants. To understand the effect of mechanic l factor on creep strai on SCC cr ck growth rate in the light water reactor nvir nments, the creep st ain at crack tip in full life cycle is studied by elastic-plastic finite element method (EPFEM) in this paper. Study results indicate that it is suitable to use the cre p strain in front of crack tip as a mechanical factor of SCC behaviors, and also show that wedgi g stress is the main mechanical factor affecting creep strain in micro cr ck stage, while external load are gradu lly becoming t e main mechanical factor i long crack st ge. Crack propagation rate is very slow in micro crack stage, and it will exp nd rapidly under the co bined effect of residual stress and working load if there is an initial crack l. © 2018 The Authors. Publishe by Elsevier B.V. Peer-review under res onsibili y of the ECF22 organizers. Keywords: Full life cycle; Elastic-plastic FEM simulation; C ep strain; Nickel-based alloy 600 1. Introduction Stress corrosion cracking (SCC) is a failure mechanism that is caused by environment, susceptible material and tensile strain of nuclear power structural materials under high temperature and high pressure aqueous environments [1-3]. Because many stainless steel components are subject to SCC in light water reactors, many efforts have been mad to understand the underl ing mecha ism of SCC and to develop predictive model for lifetime estimation [4]. © 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. Abstract

Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation. * Corresponding author. Tel.: +49-241-80-92912; fax: +49-241-80-92253. E-mail address: xue_he@hotmail.com * Corresponding author. Tel.: +49-241-80-92912; fax: +49-241-80-92253. E-mail address: xue_he@hotmail.com

* 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 © 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.2018.12.273