PSI - Issue 2_A

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com cienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structu al Integrity 2 (2016) 761–768 Available online at www.sciencedirect.com ScienceDirect 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 Examination of methods for the treatment of constraint effects within the FAD approach I. Varfolomeev a *, F. Dittmann b a Fraunhofer IWM, Wöhlerstr.11, 79108 Freiburg, Germany b Karlsruhe Institute of Technology (KIT), Engelbert Arnold-Str. 4, 76131 Karlsruhe, Germany Abstract This paper presents results of a study focusing on the effect of crack-tip constraint on the fracture behaviour of metallic materials. The principal goal is to validate two analytical methods for the consideration of constraint effects in engineering failure assessment – the R6/FITNET approach and the IST methodology. Those methods are briefly reviewed and applied to analyse available experimental data obtained in fracture tests on various cracked geometries and for two materials. Comparing to the conventional route which incorporates fracture toughness values derived in tests on highly constrained standard specimens, both methods provide an improved (less conservative) failure assessment. However, the assessment results from both methods are shown to be st ongly dependent o the Weibull exponent ݉ which determination requi s a certain level of ex tise in the f eld of fracture mechanics. Since non-conservative results are p ssible when assuming high ݉ values, car should be taken to nsur a proper pplication of t e respective assessment methodology. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: constraint; stress triaxiality; analytical failure assessment; failure assessment diagram (FAD) 1. Introduction Assessment of crack-like defects in components by means of the FAD (failure assessment diagram) approach may lea to an ove -conservative failure prediction pr vided that material fracture toughness employed in the assessment has been obtained in tests of deeply cracked standard specimens, according to existing standards, e.g. rf a b Peer-review under responsib of the Scientific C 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.

* Corresponding author. Tel.: +49-761-5142-210; fax: +49-761-5142-401. E-mail address: igor.varfolomeev@iwm.fraunhofer.de

* 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.2016.06.098