PSI - Issue 3

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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. Copyright © 2017 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of the Scientific Committee of IGF Ex-Co. XXIV Italian Group of Fracture Conference, 1-3 March 2017, Urbino, Italy Chang f misorientation of individual grains in fatigue of polycrystalline alloys by diffraction contrast tomography using ultrabright synchrotron radiation Y. Nakai a *, D. Shiozawa a , N. Asakawa a , K. Nonaka a , and S. Kikuchi a a Department of Mechanical Engineering, Kobe University, 1-1, Rokodai, Nada, Kobe 657-8501, Japan Abstract A three-dimensional grain mapping technique for polycrystalline materials, called X-ray diffraction contrast tomography (DCT), was developed at SPring-8, which is the brightest synchrotron radiation facility in Japan. The developed technique was applied to an austenitic stainless steel. The shape and location of grains could be determined by DCT using the apparatus in a beam line of SPring-8. To evaluate the dislocation structure in fatigue, the total misorientation of individual grains was measured by DCT. The average value of the total misorientation over one sample was increased with the number of cycles. In a grain, the change of the total misorientation was largest for the p imary slip plane. The m xim m change of the total misorientation in fatigue was larger for planes wi h larger Schmid factor, and the first fatig e crack in tiation was occurred in a grain, which had he greatest change of the tot l misorientation. © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of IGF Ex-Co. Keywords: Synchrotron radiation, Diffraction contrast tomography, Total misorientation, Dislocation density, Fatigue damage, Crack initiation Fatigue damage of metallic materials before crack initiation is believed to be the change of the dislocation structure during cyclic loading (Suresh, 1991), and several methods have been proposed for the evaluation of the fatigue damage. Among them, X-ray diff action technique has received considerable attention because the change in microscopic structure of materials during fatigue and plastic deformation can be detected throughout the process from XXIV Italian Group of Fracture Conference, 1-3 March 2017, Urbino, Italy Change of misorientation of individual grains in fatigue of polycrystalline alloys by diffraction contrast tomography using ultrabright synchrotron radiation Y. Nakai a *, D. Shiozawa a , N. Asakawa a , K. Nonaka a , and S. Kikuchi a a Department of Mechanical Engineering, Kobe University, 1-1, Rokodai, Nada, Kobe 657-8501, Japan Abstract A three-dimensional grain mapping technique for polycrystalline materials, called X-ray diffraction contrast tomography (DCT), was d velop d at SPring-8, which is he brightest synch otron radiation f cility in Japan. The developed technique w s applied to an austenitic st inless steel. The shape and loca ion of grains could be determined by DC using the apparatus in a be m ne of SPring-8. To evaluate th dislocation structure in fatigue, the total misori ntatio of individual grains was measured by DCT. The avera e value of the to al mi rientation ove o e sample was increa ed with the number of cycles. In a grain, the change of t total misorientation was argest for the prima y slip plan . The maximum c ang of th t tal misorie tation fatigue was larger f r pla es with larg r Schmid factor, and the fir t fatigue crack initiation was occurred in grain, wh ch had the gre est cha ge of the total misorientation. © 2017 The Authors. Published by Elsevier B.V. Peer-revi w under espons bility of th Scientific Committee of IGF Ex-Co. Keywords: Synchrotron radiation, Diffraction contrast tomography, Total misorientation, Dislocation density, Fatigue da age, Crack initiation 1. Introduction Fatigue damage of metallic materials before crack initiation is believed to be the change of the dislocation structure during cyclic loading (Suresh, 1991), and s veral m th ds have b en proposed for th evaluation of the fatigu ama e. Among them, X-ray diffraction t chnique as received considerable attention bec use the change in microscopic structure of mat rials du ing fatigue and plastic deformation can be d tec d througho t the process from © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation. 1. Introduction

* Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452-3216 © 2017 The Authors. Published by Elsevier B.V. Peer-review und r responsibil ty of the Scientific Committee of IGF Ex-Co. 2452-3216 © 2017 The Authors. Published by Elsevier B.V. Peer review under r sponsibility of the Scientific Committee of IGF Ex-Co. * Corresponding author. Tel.: +81-78-803-6128; fax: +81-78-803-6155. E-mail address: nakai@mech.kobe-u.ac.jp * Corresponding author. Tel.: +81-78-803-6128; fax: +81-78-803-6155. E-mail address: nakai@mech.kobe-u.ac.jp

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Copyright © 2017 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ). Peer-review under responsibility of the Scientific Committee of IGF Ex-Co. 10.1016/j.prostr.2017.04.058