PSI - Issue 2_A

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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 Struc ural Integrity 2 (2016) 2014–2021 Structural Integrity Procedia 00 (2016) 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. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Assessment of crack-related problems in layered ceramics using the finite fracture mechanics and coupled stress-energy criterion Old ř ich Ševe č ek a *, Michal Kotoul a , Dominique Leguillon b , Eric Martin c , Raul Bermejo d a Brno University of Technology, Institute of Solid Mechanics, Mech tronics and B om chanics, Technicka 2896/2, 616 69 Brno, Czech Republic b Institut Jean le Rond d'Alembert, CNRS UMR 7190, Sorbonne Universités, UPMC Université Paris 06, F-75005 Paris, France c Laboratoire des Composites Thermo-Structuraux, CNRS UMR 5801, Université de Bordeaux, F-33600 Pessac, France d Montanuniversitaet Leoben , Institut für Struktur- und Funtionskeramik, Peter-Tunner Straße 5, 8700 Leoben, Austria Abstract This contribution gives an overview of different fracture-mechanics issues occurring in layered ceramics designed with internal compressive residual stresses (such as the edge cracking, crack arrest by the compressive layer or crack deflection/bifurcation) and proposes an effective approach to describe the initiation and/or propagation of cracks in such materials. The finite fracture mechanics (FFM) theory and the coupled stress-energy criterion (CC) are discussed and applied to understand their fracture behavior. The stress-energy coupled criterion is based on the tensile strength and toughness data of investigated material and it does not contain any adjustable parameter, which is its indisputable advantage. It could thus (in the considered brittle materials) predict both crack initiation and crack propagation under consideration of both thermal and external mechanical loading. A case study is investigated, where edge cracking in compressive layers can be predicted as a function of the thickness of the compressive layer and the magnitu e f residual stresses. Another case study concerns the onset of a cra k in a n tched sampl of a layered ceramic submi ted to bending. The propagation of the cr ck through the ceramic laminate is stud ed s a function of th volume ratio of particular m terial compon nts and corresp nding magnitude of residual stresses in both compressive and tensile ay rs. Under certain combination of residual stress and layered archit cture, t CC predicts crack arrest in he inte nal compressive layer of the l minat in accordance with experiment l observations under similar loading conditions. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsi ility of the Scientific Committee of ECF21. ot a l b c d o - e 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. © 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. Keywords: Layered ceramics; crack bifurcation; edge cracking; Finite Fracture Mechanics; Coupled Criterion

* Corresponding author. Tel.: +420 5 4114 2857; fax: +420 54114 2876. E-mail address: sevecek@fme.vutbr.cz

* 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.

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.2016.06.253