PSI - Issue 2_A

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com ienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Struc ural Integrity 2 (2016) 1093–11 Available online at www.sciencedirect.com ScienceDire t 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 Effect of martensite content and geometry of inclusions on the VHCF properties of predeformed metastable austenitic stainless steels Andrei Grigorescu a *, Anton Kolyshkin a , Martina Zimmermann b , Hans-Jürgen Christ a a Institut für Werkstofftechnik, Universität Siegen, 57068 Siegen, Germany b Institut für Werkstoffwisse chaft, TU Dresden, Helmholtzstraße 7, 01062 Dresden, Germany Abstract The effect of inclusions on the VHCF properties of a metastable austenitic stainless steel in the predeformed condition was studied. The material contains an inhomogeneous distribution of oxide inclusions with an elongated geometry in the rolling direction. Samples were monotonically predeformed at -80°C start temperature at a strain rate of 0.1 %/s resulting in a martensite content of about 60 vol-% and subsequently fat gued by means of high frequency testing machin s. On the ne ha d the high martens te content result in an increase of the HCF strength, on the other hand f tigue failure ccurs ven b y nd 10 7 loadi g cycl s. The higher n tch sensitivity of the martensite phase leads to in ernal crack initiation from inclusions acc mpanied by the formation of a fine granular area (FGA). A direct correlation between the size of the FGA- nd the number of cycles to failure c n be shown. In ord r to find the optimal rte site content for both HCF and VHCF regime, the notch sensitivity of the material in different predeformed conditions was investigated. The results show a significantly higher notch sensitivity for 30 v ol% α’ martensite, whereas higher martensite contents do not show any further significant increase. Since mechanical components are in practice subjected to complex cyclic loading situations, samples were extracted and tested both parallel and transversal to the rolling direction, in order to reproduce the relation between rolling and loading direction. The change in testing direction perpendicular to the rolling direction results in a larger projection area of the inclusions and reduces the number of cycles to failure due to the increased stress intensity factor. In this case, the area of the inclusions (but not of the FGA) correlates with the number of cycles to failure. These findings are discussed on the basis of a detailed microstructural characterization of the material focusing on the effect of martensite content, the inclusion morphology with respect to the rolling direction and the load axis applied. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Effect of martensite content and geometry of inclusions on the VHCF properties of predeformed metastable austenitic stainless steels Andrei Grigorescu a *, Anton Kolyshkin a , Martina Zimmermann b , Hans-Jürgen Christ a a Institut für Werkstofftechnik, Universität Siegen, 57068 Siegen, Germany b Institut für Werkstoffwissenschaft, TU Dresden, Helmholtzstraße 7, 01062 Dresden, Germany Abstract The effect of inclusions on the VHCF properties of a metastable austenitic stainless steel in the predeformed condition was studi d. The material contains an inhomogeneous distribu ion of oxid inclu io s with an elongated ge metry in the rolling direction. Samples were monotonically pred formed at -80°C start temp rature at a tra n r te of 0.1 %/s r sulting in a martensite content of bout 60 vol-% and subsequently fatigued by means of high frequency esting machines. On the o e hand the high mar e site content resu ts in an incr ase of the HCF strength, on th ot e hand fatigue failure occurs even beyond 10 7 load ng cycl s. The higher notch se sitivity of the martensite phase leads o internal crack initiatio f om inclusions accompani by the formation of a fin granular area (FGA). A irect correlatio between the size of the FGA-and the number of cy les to failure can be show . In order t find the optim l martensi e nt nt f r o h HCF and VHCF regime, the notch sensitivit f the mate ial i different predeformed conditi ns was inv stigated. The resul s show a significantly igher tch sensitivity or 30 v ol% α’ martensite, wher as higher martensite co ten s do not s ow any further signifi ant increase. Since mechan cal components are in pr ctice subjected to complex cyclic loading situations, samples were extracted and test d both parallel and transversal to the rolling direction, in order to reproduce the relation between rolling and loa ing direction. The change in testing direction perpendicular to the rolling dir cti n r sults in larger projection area of the inclus ons and reduces the number of cycles to failure due to the increased stress intensity factor. In this case, the area of the inclusions (but not of the FGA) corr lates with the numb r of cycl s to f ilure. These findings are discu sed on the basis of a detailed micros ruc ural characterization of the material focusing on the eff ct of martensite content, the inclusion morphology wi h r spect t he rolling di e ion nd the load axis applied. Copyright © 2016 The A thors. 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. © 2016 The Authors. Published by Elsevier B.V. © 2016 The Authors. Published by Elsevier B.V.

* 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. * Corresponding author. Tel.: +49 (0)271/740-3422; fax: +49 2717402545 E-mail address: andrei.grigorescu@uni-siegen.de 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 (0)271/740-3422; fax: +49 2717402545 E-mail address: andrei.grigorescu@uni-siegen.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.2016.06.140