PSI - Issue 13

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com ienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 P o edi Structural Integr ty 13 ( 8) 3–10 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 f the ECF22 organizers. ECF22 - Loading and Environmental effects on Structural Integrity Analysis of stress corrosion cracking in X80 pipeline steel: An approach from the theory of critical distances P. González a *, S. Cicero a , J.A. Álvarez a , B. Arroyo a a LADICIM (Laboratorio de la División de Ciencia e Ingeniería de los Materiales), Universidad de Cantabria. ETS Ingenieros de Caminos, Canales y Puertos, Av/Los Castros 44, Santander 39005, España. Abstract This paper presents an analysis of Stress Corrosion Cracking (SCC) based on the Theory of Critical Distances (TCD). The research is based on a experime tal program composed of fracture specimens with notch radius varying from 0 mm (crack-like defect) up to 1 mm, and tensile specimens. A pipeline steel was used in this work (X80). It has been analysed in one hydrogen embrittlement situation. The study has been completed with Finite Elements Simulation analysis. The capacity of the TCD to analyse SCC processes has been proven. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: Hydrogen Embrittlement; Theory of Critical Distances; Notch Effect; Environmental Assisted Cracking, Stress Corrosion Cracking. 1. Intro uction A critical aspect concerning high strength steels is their resistance to Stress Corrosion Cracking (SCC) and Hydrogen Embrittlement (HE) phenomena, both of which lead to degradation of the mechanical properties of these steels when facing aggressive environments (Hamilton (2011), Tiwari et al. (2000) and Rehrl et al. (2014)). The effect of hydrogen is especially significant in high-strength steels exposed to aqueous environments under cathodic protection (such as off-shore platforms) or those typical of H2S presence (as in gas transport pipelines). Both phenomena, HE and SCC, are similar, resulting in brittle failures in the prese ce of an aggressive environment and maintained stress. ECF22 - Loading and Environmental effects on Structural Integrity Analysis of stress corrosion cracking in X80 pipeline steel: An approach from the theory of critical distances P. González a *, S. Cicero a , J.A. Álvarez a , B. Arroyo a a LADICIM (Laboratorio de la División de Ciencia e Ingeniería de los Materiales), Universidad de Cantabria. ETS Ingenieros de Caminos, Canales y Puertos, Av/Los Castros 44, S ntander 39005, Españ . Abstract This paper presents an analysis of Stress Corrosion Cracking (SCC) based on the Theory of Critical Distances (TCD). The research is based on an experimental program composed of fracture specimens with notch radius varying from 0 mm (crack-like defect) up to 1 mm, a d tensile specimens. A pipeline steel was used in this work (X80). It has been analysed in one hydrogen embrittlement situatio . The study has been completed with Finite Elements Simulation analysis. The capacity of the TCD to analyse SCC processes has been proven. © 2018 The Authors. Published by Elsevier B.V. Peer-review under respons bility of the ECF22 organizers. Keywords: Hydrogen Embrittlement; Theory of Critical Distances; Notch Effect; Environmental Assisted Cracking, Stress Corrosion Cracking. 1. Introduction A critical aspect concerning high strength steels is their resistance to Stress Corrosion Cracking (SCC) and Hydrogen Embrittlement (HE) phenomena, both of which lead to degradation of the mechanical properties of these steels when facing aggressive environ ts (Hamilton (2011), Tiwari et al. (2000) and Rehrl et al. (2014)). The effect of hydrogen is especially sig ificant in high-strength steels exposed to aqueous environments under cathodic prot cti n (such as off-shore platforms) or those typical of H2S presence (as in gas tra sport pipelines). Both henome a, HE and SCC, are similar, resulting in brittle failures in th presence of an aggressive enviro ment and mai tained stress. © 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.: +34 622 01 47 75 E-mail address: pablo.glez@unican.es * Corresponding author. Tel.: +34 622 01 47 75 E-mail ad ress: pablo.gl z@unican.es

* 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 o ganizers.

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.2018.12.002