PSI - Issue 2_A

ScienceDirect Available online at www.sciencedirect.com Av ilable online at ww.sciencedire t.com cienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Struc ural Integrity 2 (2016) 3345–3352 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 Experimental and nume i al investigations on limit str ins in ductile fracture Florian Fehringer a *, Michael Seidenfuß a , Xaver Schuler b a Institute for Materials Testing, Materials Science and Strength of Materials (IMWF) – University of Stuttgart, Pfaffenwaldring 32, 70569 Stuttgart, Germany b Materials Testing Institute (MPA) – University of Stuttgart, Pfaffenwaldring 32, 70569 Stuttgart, Germany Abstract Several incidents in the past showed the risk of a human and/or environmental caused accident which exceeds the design limit of a component. Therefore the quantification of safety margins becomes necessary. According to technical standards, the safety assessment is usually based on stress criteria. The deformation capability of the material is hardly taken into account with these criteria. Limit strain based safety assessment concepts can overcome this disadvantage. The main influenc factors on limit strains are the stress triaxiality, the component size, the loading path and the strain rate. To quantify these factors, diff rent experiments are performe with specim ns made of the steel 20MnMoNi5-5, which is representative f r German nuclear ower-plants. In the ange of high stress triaxia ity values, different specimens are tested. All the specimens are simul ted using Rousselier model to deriv the crack initiation location and time. The experimental and numerical results can be us d deriv a limit strain curve. The influ nce of loading paths on fai ur strains is show at pre-loaded notched tensile specimens. Finally, an outlook on the planned xperim ntal and numerical investigations in the r nge of small stres triaxi lity valu s is given. © 2016 The Authors. Published by Elsevier B.V. Peer-r view under responsibility of the Scie tific Committee of ECF21. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Experimental and numerical investigations on limit strains in ductile fracture Florian Fehringer a *, Michael Seidenfuß a , Xaver Schuler b a Institute for Materials Testing, Materials Science and Strength of Materials (IMWF) – University of Stuttgart, Pfaffenwaldring 32, 70569 Stuttgart, G rmany b Materials Testing Institute (MPA) – University of Stuttgart, Pf ffenwaldring 32, 70569 Stuttgart, Germany Abstract Several incidents in the past showed the risk of a human and/or environmental caused accident which exceeds the design limit of a compo ent. Therefore the quantification of s fety margins b comes n cessary. Accor ing to techni al standard , the safety ssessme t is usually based on stress cr teria. The deformation capability of the material is hardly taken into ccount with th se crit ria. Limit strain based safety as essm nt conc pts can overcome this disadvantag . The main influence factors on limit strains are th stress triaxiality, e component size, the loading path and the strain rate. To quantify these factors, different expe ments are p rfo med with specimens made of the steel 20M MoNi5-5, which is representative for Ge man nuclear powe -pla ts. In the range o high stress triaxiality values, different specim ns are tes ed. All the specimens are s mulated using Rousselier mod l to derive the crack init ation location an tim . The experimental and numeric l results can b used to derive a l mit tr in curv . The influ nce of l ad ng pa s on failure s rains is shown at pre-lo ed notched ten ile specimen . Fi ally, an outlook on the planned experimental nd numerical inv stiga ions in the rang of small tress t i xiality values is g ven. © 2016 The Author . Publ shed by Elsevier B.V. Peer-revi w under r spons bility of the Sc entific Committee of ECF21. 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: limit strains; Rousselier model, pr -load, stress triaxiality, lode angle Keywords: limit strains; Rousselier model, pre-load, stress triaxiality, lode angle

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 und r responsibility of the Scientific Committee of ECF21. 2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer review under r sponsibility of the Scientific Committee of ECF21. * Corresponding author. Tel.: +49 711 685 69695 ; fax: +49 711 685 62635 . E-mail address: Florian.Fehringer@imwf.uni-stuttgart.de * Corresponding author. Tel.: +49 711 685 69695 ; fax: +49 711 685 62635 . E-mail ad ress: Florian.Fehringer@imwf.uni-stuttgart.de

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.2016.06.417