PSI - Issue 13

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 Structural Integrity 13 (2018) 1583–1588 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 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. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. ECF22 - Loading and Environmental effects on Structural Integrity Low-cycle fatigue hysteresis by thermographic and digital image correlation methodologies: a first approach Guido La Rosa, Carmelo Clienti, Adriana Marino Cugno Garrano, Fabio Lo Savio DICAR, University of Catania, Via S. Sofia 64, 95123 Catania, Italy Abstract The energetic behaviour of the material under low-cycle fatigue (LCF) can be controlled by the hysteresis cycle in order to define the variation of the mechanical characteristics and to forecast the fatigue and the failure response. The traditional analysis is performed using the force-displacement signals derived by the testing machine that can be coupled with other measuring methodologies. In h present p per, the authors have used the Digital Image Correlation (D.I.C.) to better define the specimen displacement, avoiding many errors of the displacement measurement chain. The thermographic analysis (T.A.), able to follow quickly and with great accuracy the energetic variations, was combined with the stress-strain measurements, allowing to calculate the damping energy. The results pointed out a similar behaviour between the hysteresis areas defined basing on the D.I.C. displacements and those found by the testing machine outputs, but substantial differences in terms of values. The thermal variations and the areas of the hysteresis loops, both linked to the plastic energy, were compared, showing a reliable agreement. © 2018 The Aut ors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: Low-cycle fatigue; Hysteresis; Digital Image Correlation (D.I.C.); Thermography. 1. Introduction The fatigue phenomenon is provoked by the crack nucleation and propagation, together with the production of plastic energy, incr asing with the fracture growth. It has been shown that the thermographic analysis enables an assessment and prediction of the fatigue life based on the analysis of the surface radiometric temperature irradiated from specimens or mechanical components subjected to cyclic loading (Boulanger et al. 2004, Giancane et al. 2009, Charkaluk and Constantinescu 2009, Crupi et al. 2010 and 2011, Naderi et al. 2010, Plekhov et al. 2007, La Rosa and Risitano 2000, Risitano et al. 2015, Kaleta et al. 1990, Luong 1988, Meneghetti et al. 2013, La Rosa et al. 2014) and how this measurement is sensitive to the damage of the component itself. Most of these are based on the acquisition and assessment of the energy response of the material subjected to cyclic or combined trains of cycles loading; these allow the prediction of the main parameters of the fatigue response such as, as an example, the fatigue limit, the duration of the fatigue lifetime (Fargione et al. 2002) and the damage (Curà and Gallinati 2011, Risitano and Risitano 2010 and 2013, Grover 1960). ECF22 - Loading and Environmental effects on Structural Integrity Low-cycle fatigue hysteresis by thermographic and digital image correlation methodologies: a first approach Guido La Rosa, Carmelo Clienti, Adriana Marino Cugno Garrano, Fabio Lo Savio DICAR, University of Catania, Via S. Sofia 64, 95123 Catania, Italy Abstract The energetic behaviour of the material under low-cycle fatigue (LCF) can be controlled by the hysteresis cycle in order to define the variation of the mechanical char cteristics and to forecast the fatigue and the failure respons . The traditional analysis is performed using the force-displacement ig als erived by the testing machin that can be coupled with other measuring methodologies. In the present aper, the authors have used the Digit Image Correlation (D.I.C.) to b tter define the specimen displacement, avoiding many errors of the displacement measureme t chai . The th rmographic analy is (T.A.), able to follow quickly and with great accuracy the energ tic variations, was combined with the stress-strain measurements, allowing to calcu ate the damping energy. The esul s pointed out a similar behaviour bet een the hy teres s ar d fined basing on the D.I.C. displacements and those found by the testing machine outputs, but substantial diff rences in terms of values. The thermal variations and the ar as of the ysteresis loops, both linked to the plas ic energy, were compared, howing a reli bl agre m nt. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: Low-cycle fatigue; Hysteresis; Digital Image Correlation (D.I.C.); Thermography. 1. Introduction Th fatigu phenomenon is provoked by he crack nucleation and pr pagation, together with the production of plastic energy, increasing with the fracture growth. It has been shown that the thermographic analysis enables an assessment and prediction of the fatigue life based on the analysis of the surface radiometric temperature irradiated from speci ens or mechanical components subjected to cyclic loading (Boulanger et al. 2004, Giancane et al. 2009, Charkaluk and Constantinescu 2009, Crupi et al. 2010 and 2011, Naderi et al. 2010, Plekhov et al. 2007, La Rosa and Risitano 2000, Risitano et al. 2015, Kaleta et al. 1990, Luong 1988, Meneghetti et al. 2013, La Rosa et al. 2014) and how this measurement is sensitive to the damage of the component itself. Most of these are based on the acquisition and assessment of the energy response of the material subjected to cyclic or combined trains of cycles loading; these allow the prediction of the main parameters of the fatigue response such as, as an example, the fatigue limit, the duration of the fatigue lifetime (Fargione et al. 2002) and the damage (Curà and Gallinati 2011, Risitano and Risitano 2010 and 2013, Grover 1960). © 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.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452-3216 © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. 2452-3216 © 2018 The Authors. Published by Elsevier B.V. Peer review under r sponsibility of the ECF22 o ganizers.

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016.

2452-3216  2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. 10.1016/j.prostr.2018.12.323