PSI - Issue 2_B

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 Structu al Integrity 2 (2016) 626–631 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2016) 000–000 il l li t . i i t. t t l t it i

www.elsevier.com/locate/procedia . l i . /l t / i

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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. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Hydrogen embrittlement susceptibility of prestressing steel wires: the role of the cold-drawing conditions J. Toribio a, *, M. Lorenzo a , D. Vergara a a Fracture & Structural Integrity Research Group, University of Salamanca, Spain Abstract Prestressing steel wires are highly susceptible to hydrogen embrittlement (HE). Residual stress-strain state, produced after wire drawing, plays an essential role since hydrogen damage at certain places of the material is directly affected by stress and strain fields. Changes in wire drawing conditions modify the stress and strain fields and, consequently, the HE susceptibility and life in service of these structural components in the presence of a hydrogenating environment. This paper analyzes the distributions of residual stress and plastic strain obtained after diverse drawing conditions ( inlet die angle , die bearing length, varying die angle and straining path ) and their influence on HE susceptibility of the wires. The conditions for industrial cold drawing can thus be optimized, thereby producing commercial prestressing steel wires with improved performance against HE phenomena. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: hydrogen embrittlement; prestressing steel wires; cold drawing; die geometry; residual stresses and strains. 1. Introduction Cold drawing is a conforming process where a progressive reduction of wire diameter is performed in diverse stages (multi-pass drawing) to produce commercial prestressing steel wires. Plastic strains during drawing are not uniformly distributed through the wire radius, as shown by Toribio et al. (2011a). Those plastic strains are the origin of a non negligible residual stress state, which directly affects the wire performance during its life in-service. Both fields (residual stress and plastic strain states) produced after drawing play an essential role in hydrogen embrittlement (HE). brittlement susceptibility of prestressing steel wires: , a t t t l t it , i it f l , i Prestressing steel wires are highly susceptible to hydrogen embrittlem t . i l t t i t t , produced after wire i , l ti l l i t t i l t t i l i i tl t t t i i l . i i i iti i t t i i l , tl , t ti ilit li i i t t t l t i t ti i t. i l t i t i ti i l t l ti t i t i t i i iti i l t i l , i i l t , i i l t i i t t i i l ti ilit t i . iti i t i l l i t ti i , t i i l t i t l i it i i t . t . li l i . . Peer-re i w under responsibility of th i tific o itt CF2 . ittl t; t i t l i ; l i ; i t ; i l t t i . . . , . . , . (resi u l . Copyright © 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativec mmons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of the Scientific Committee of ECF21. © 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 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. l i . . i i ilit t i ti i itt . * Corresponding author. Tel.: +34 980 545 000 (ext. 3673); fax: +34 980 545 002. E-mail address: toribio@usal.es i t . l.: t. ; : . il t i i l. t . li

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Copyright © 2016 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 ECF21. 10.1016/j.prostr.2016.06.081