PSI - Issue 2_B

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com ScienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Struc ural Integrity 2 (2016) 2543–2549 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2016) 000–000 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 Prediction of ductile failure using a phenomenological model calibrated from micromechanical simulations J.K. Holmen a,b, *, L.E.B. Dæhli a,b , O.S. Hopperstad a,b , T. Børvik a,b a Structural Impact Laboratory (SIMLab), Department of Structural Engineering, Norwegian University of Science and Technology (NTNU), NO-7491, Trondheim, Norway b Centre for Advanced Structural Analysis (CASA), NTNU, NO-7491, Trondheim, Norway Abstract Unit-cell models were in this study utilized to numerically determine the failure locus of a cast and homogenized AA6060 aluminum alloy. Simulations were conducted for moderate and high stress triaxiality ratios, and for various Lode parameters between generalized tension and generalized compression. We estimated the orientation of the localization band that minimizes the failure strain in the unit-cell models for all the imposed stress states. The energy based Cockcroft-Latham (CL) failure criterion was calibrated based on the numerically determined failure locus and used in finite element simulations that we eval ated aga nst xperimental tests. Test-specim n geometrie included smooth te sion tests, notche tension tests and plane strain tension t sts. These w re designed to cover a wide range of stress states. The poi ts of failure i the experim ntal tests were predicted with reasonable accuracy by the numerical simulations. We see that the method used for numerically determining the failure locus can be improved by refining the micromechanical simulations. Better agreement between the simulations and the experiments can also be obtained, for instance by employing a different macroscopic failure criterion than the CL criterion. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: Unit-cell models; Finite element simulations; Ductile failure; Numerical prediction; Experimental validation 1. Introduction Both the stress triaxial ty ratio and the Lode parameter influence ma erial response and the development of damage in metals. Because of this, several material tests are needed to extract enough data to calibrate macroscopic failure criteria for all relevant stress states. Previous works have successfully managed to predict the yield stress and 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Prediction of ductile failure using a phenomenological model calibrated from micromechanical simulations J.K. Holmen a,b, *, L.E.B. Dæhli a,b , O.S. Hopperstad a,b , T. Børvik a,b a Structural Impact Laboratory (SIMLab), Department of Structural Engineering, Norwegian University of Science and Technology (NTNU), NO-7491, Trondheim, Norway b Centre for Advanced Structural Analysis (CASA), NTNU, NO-7491, Trondheim, Norway Abstract Unit-cell models were in this study utilized to numerically determine the failure locus of a cast and homogenized AA6060 aluminum alloy. Simulations were conducted for oder te and high stress tr axiality rati s, and for vari us Lode parameters between generalized tens and generalized compression. We estimated the orientation of the localization band that minimize the failure str in in he unit-cell mode s for all th imposed stress states. Th energy based Cockcroft-L tham (CL) failure criterion was calibra ed based on the numerically determined failure locus and used in finite element simulations th t w evaluated against exp rimental tests. Test-specimen g ometri s inc ded smooth ten ion tests, notched ten on tests and plan str in nsion tests. These were design d o cover a wide range of str ss tates. The points of failur in the exp rime tal tests w re predicted with reasonable accuracy by the numeri al simulations. W se that the method used o um rically determining th failure l cus can be improved by refining the micromechanic l simulations. Better agr ement betwee the simu ations and the exper ments an ls be obtaine , for insta ce by employing a different macroscopi failur criterion tha CL crit rion. © 2016 The Authors. Published by Elsevier B.V. Peer-review under espons bility of the Scientific Committee of ECF21. Keywords: Unit-cell models; Finite element simulations; Ductile failure; Numerical prediction; Experimental validation 1. Introduction Both the stress triaxiality ratio and the Lode parameter influence material response and the development of damage in me al . Beca se of this, several material tests ar needed to extract enough data to calibrat macroscopic f ilure criteria for all relevant stress states. Previous works hav successfully ma aged to predi t the yield st e s and Copyright © 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://cr ativecommons.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.: +47 93 04 58 37. E-mail address: jens.k.holmen@ntnu.no * Corresponding author. Tel.: +47 93 04 58 37. E-mail address: jens.k.holmen@ntnu.no

* Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review und r 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 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.2016.06.318