PSI - Issue 13

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at www.sciencedire t.com cienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structural Integrity 13 (2018) 2233–2238 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000 – 000 Available online at www.sciencedirect.com 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. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. ECF22 - Loading and Environmental effects on Structural Integrity Recent Studies of Hydrogen Embrittlement in Structural Materials Dan Eliezer a, *, Ravit Silverstein b a Department of Material Engineering, Ben-Gurion University of the Negev, Beer-Sheva, Israel b Materials Department, University of C lifornia, Santa Barbara, California Abstract Mechanical properties of metals and their alloys are most ofte determined by interstitial atoms. Hydrogen, as one common interstitial element, is often found to degrade the fracture behavior and lead to premature or catastrophic failure in a wide range of materials, known as hydrogen embrittlement. This topic has been studied for more than a century, yet the basic mechanisms of such degradation remain in dispute for many metallic systems. his work attempts to link, experimentally and theoretically, between failure, caused by the presence of hydrogen, and second phases, lattice distortion, and deformation levels. The connection between hydrogen embrittlement and pathway is established through examination of the evolved microstructural state by hydrogen. Calculations performed by thermal desorption analysis showed the effectiveness of high trapping energy levels in preventing the hydrogen embrittlement phenomena. It was proved that the embrittlement model is highly affected by the trapping mechanisms. These results were confirmed by a diffusion calculation model and a theoretical model that predicts hydrogen trapping mechanis s. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: Hydrogen; structure materials; thermal desorption analysis (TDA) 1. Introductions Hydrogen can have a deleterious ff ct on metals, since only a small amount is enough to cause a serious degradation in th metal' mechanical properties. Hydrogen's influence on a metal's microstructure and mechanical properties, known as hydrogen assisted cracking (HAC), is affected by the hydrogen's chemical interaction with the metal, hydrogen absorption, and hydrogen trapping levels. The latter is affected particularly by second phases in the ECF22 - Loading and Environmental effects on Structural Integrity Recent Studies of Hydrogen Embrittlement in Structural Materials Dan Eliezer a, *, Ravit Silverstein b a Department of Material Engi eri g, Ben-Gurion University of the Negev, Be r-Sheva, Israel b Materials Department, University of California, Santa Barbara, California Abstract M chanical properties of metals and their alloys re most often determined by interstitial atoms. Hydrogen, as one common interstitial element, is often found to degrade the fracture behavior and l ad to premature or catastrophic failure in a wide range of mat rials, known as hydrogen embrittlement. This topic has been studied for more than a century, yet the basic mechanisms of such degradation remain in dispute for many m tallic systems. This work attempts to li k, xperimentally and theoretically, betwee failure, caus d by the pres nce of hydroge , and second phases, lattice distortion, a d deformation le ls. The connection between hydrogen embrittlement and pathway is est blished t r ugh examination of the evolved microstructural state by hydroge . Calculations perform d by t ermal desorption analysis showed the effectiveness of i trapping energy levels in pr venting the hydrog n embrittl me t phenomen . It was proved that the embrittlement m d l is highly affected by the trapping mecha isms. The e results were co f rmed by a diffusion calculation mod l a d a theoretical model that pre icts hydrogen trapping mechanisms. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: Hydrogen; structure materials; thermal desorption analysis (TDA) 1. Introductions Hydrog n can av a deleteri us effect on metals, since o ly a small a ount is enough to cause a serious degradation in the metal's m chanical properties. ydrogen's influence on a metal's microstructure and mechanical properties, known as hyd oge ssist d cracking (HAC), is affected by the hy rogen's chemical interaction with t metal, hydrogen absorption, and hydrogen trapping levels. The latter is affected particularly by second phases in the © 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.

* Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452 3216 © 2018 Th Authors. Published by Elsevie 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. * Corresponding author. Tel.: +972 54 222 8748; fax: +972 E-mail address: deliezer@bgu.ac.il * Corresponding author. Tel.: +972 54 222 8748; fax: +972 E-mail address: deliezer@bgu.ac.il

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.2018.12.135