PSI - Issue 13

ScienceDirect Available online at www.sciencedirect.com Available online at ww.sciencedire t.com Sci ceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structural Integrity 13 (2018) 18 4–181 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural I t 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 Through Process Modeling of the Fracture Toughness Test of Multipass Welds Incorporating Residual Stress Distribution Yoshiki Mikami a, *, Houichi Kitano b , Tomoya Kawabata c a Joining and Welding Research Institute, Osaka University, 11-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan a National Institute for Materials Science, 11-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan c Graduate School of Engineering, The University of Tokyo, Hongo 7-3-1, Bunkyo, Tokyo 113-8656, Japan Abstract Weld residual stress inevitably occurs in multipass welds of thick steel plates, and it affects the fracture toughness testing procedure and test results; therefore, it is important to clarify the effect of residual stress on fracture toughness evaluation. However, it is almost impossible to measure the entire residual stress distribution in welded joints and to consider the detailed distribution in fracture toughness testing. Therefore, in this study, a numerical simulation method to model the fracture toughness test considering the weld residual stress is developed. The weld residual stress incorporated into the simulation was validated through experimental measurement. The tr nsition of the residual stress thr ughout the processes of mult pass welding, specimen machining, residual str s modification, precracking, a d fracture toughness testing were evaluated using the proposed me hod. Three-point bend fractu e toughness test simulations were performed for the following three cases: (1) base metal, (2) as-welded joint, and (3) residual stress modified (reverse bent) specim n by reverse bending. It was shown that the residual s ress distribution in ultipass welded joint was effectively modified by reverse be ing. Finally, it w s demonstrated that residual str ss has a considerabl influence n the crack-tip opening profile. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. ECF22 - Loading and Environmental effects on Structural Integrity Through Process Modeling of the Fracture Toughness Test of Multipass Welds Incorporating Residual St ess Distribution Yoshiki Mikami a, *, Houichi Kitano b , Tomoya Kawabata c a Joining and Welding Research Institute, Osaka University, 11-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan a National Institute for Ma erials Science, 11-1 Mihogaoka, Ibara i, Os k 567-0047, Japan c Graduate School of Engineering, The University of Tokyo, H ngo 7-3-1, Bunkyo, Tokyo 113-8656, Japan Abstract Weld residual stress inevitably occurs in multipass welds of thick steel plates, and it affects the fracture toughness testing procedure and test result ; therefore, it is important to cl rify the effect of r sidu l stress on fra ture toughness evaluation. However, it is lmost impossible to measure the entire residual stress distribution in weld d j ints and to consider the detailed distribution in fracture toughness testing. Therefore, in this st dy, a numerical simulation method to model the fracture toughness test considering the weld residual stress is dev loped. The weld residual stress incorporated into the si ulation was validated through experim ntal m asurement. The transition of the residual stress throughout the rocesses of multipass welding, specimen machining, residu l stress modificati n, precracking, and frac ure toug ness testing were evaluated using the proposed method. Three-point bend fracture toughness test sim lations w re performed for the following thre c ses: (1) base metal, (2) as-welded joint, and (3) r sidual stress modified (reverse bent) specimen by reverse bending. It as s own t at the residual stress distribution in multipass welded joint was effectively modified by reverse bending. Finally, it was demonstrated that residual stress has a considerable influence on the crack-tip opening profil . © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: fracture toughness test; crack-tip opening displacement; multipass welds; residual stress modification

© 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: fracture toughness test; crack-tip opening displacement; multipass welds; residual stress modification

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

* Corresponding author. Tel.: +81-6-6879-4371. E-mail address: mikami@jwri.osaka-u.ac.jp * Corresponding author. Tel.: +81-6-6879-4371. E-mail ad ress: mikami@jwri.osaka-u.ac.jp

* 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 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.2018.12.356