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) 1047–1054 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

www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia

www.elsevier.com/locate/procedia

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 Very high cycl fatigue of wrought magnesium alloy AZ61 U. Karr a,* , A. Stich b , H. Mayer a a Institute of Physics and Materials Science, University of Natural Resources and Life Sciences, Vienna, Austria b Audi AG, Ingolstadt, Germany Abstract Wrought magnesium alloys show a high strength to weight ratio, which makes them potentially attractive for load bearing components in auto otive applications. Structural parts may be subjected to very high num ers of load cycles, and therefore the very high cycle fatigue properties of these materials are of great interest. Fatigue tests in laboratory air were carried out on wrought magnesium alloy AZ61 using ultrasonic fatigue testing equipment. The fatigue strength at 10 9 cycles is 98 MPa, which is 32% of the tensile strength. Fatigue cracks are predominantly initiated from slip bands at the surface. Near threshold fatigue crack growth was studied in ambient air and vacuum and showed a dominant influence of the environment. The threshold stress intensity amplitude at load ratio R=-1 is K a,th = 1.1 MPam 1/2 in air and 1.9 MPam 1/2 in vacuum. Crack propagation as small as 10 12 m/cycle could be documented in vacuum. Lowest growth rates observed in ambient air were about 10 -10 m/cycle. In vacuum, a transgranular and ductile crack path is found for all investigated crack growth rates. Corrosive processes induced by ambient air cause a transition from ductile to brittle failure in the near threshold regime. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: Ultrasonic fatigue; Fatigue crack growth; Threshold stress intensity; Environmental influence; Magnesium alloy 1. Introduction The low mass density and the high specific strength make magnesium alloys potentially interesting materials for applications where weight saving is an issue. Some applications already exist in automotive systems where the reduction of mass and consequential energy saving and emission reduction are most important aims in research and development. But still the application of magnesium alloys as load bearing components is limited. One reason is 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Very high cycle fatigue of wrought magnesium alloy AZ61 U. Karr a,* , A. Stich b , H. Mayer a a Institute of Physics and Materials Science, University of Natural Resources and Life Sciences, Vien a, Austria b Audi AG, Ingolstadt, Germany Abstract Wrought magnesium alloys show a high strength to weight ratio, which makes them potentially attractive for load bearing components in automotive applications. Structural parts may be subjected to very high numb rs of load cycles, and therefore the very high cycle fatigue pro erties f these materials are of great interes . Fatigue tests in lab rat ry air were carried ut on wrought magn sium alloy AZ61 using ultrasonic fatigue testing equipm n The fatigue trength at 10 9 cycles is 98 MPa, which is 32% of the tensile strength. Fatigue cracks are predominantly initiated from slip bands at the surface. N ar threshold fatigue crack gr wt was studied in ambient air nd v cuum and showed a dominant inf uence of the environment. The threshold stress inten ity amplitude at load ratio R=-1 is K a,th = 1.1 MPam 1/2 in air n 1.9 MPam 1/2 i vacuum. Crack propagation as mall as 10 12 m/cycle could b documen ed in vacuum. Lowest growth rates observed in bie t air were about 10 -10 m/cycle. In v cuum, a transgranular and ductile crack path is found f r all inves igated crack growth rates. Corrosiv pr cesses induced by ambient air c use a transition from du tile to brittle failure in the ear threshold regime. © 2016 The Autho s. Publish d by Elsevier B.V. Peer-review under espons bility of the Scientific Committee of ECF21. Keywords: Ultrasonic fatigue; Fatigue crack growth; Threshold stress intensity; Environmental influence; Magnesium alloy 1. Introduction The low mass density and the high specific strength make magnesium alloys potentially interesting materials for applications where weight saving is an issue. So e applications already exi t in automotiv systems where the redu tion of mass and conseque tial energy saving and em ssion reduction are most important aim in research and d velopment. But still the application of magnesium alloys as loa bearing co ponents is lim ted. One reason is Copyright © 2016 The Authors. ublished by E sevier B.V. This is an open access rticl under the CC BY-NC-ND license (http://creativecommons.org/lice ses/by-nc- /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.: +43-1-47654-5174. E-mail address: ulrike.karr@boku.ac.at * Corresponding author. Tel.: +43-1-47654-5174. E-mail address: ulrike.karr@boku.ac.at

* 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 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.2016.06.134