PSI - Issue 5

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 Structu al Integrity 5 (2017) 92 –927 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2017) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2017) 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. A Fracture Mechanics Study of a Compact Tension Specimen: Digital Image Correlation, Finite Element and Meshless Methods Behzad V. Farahani a,b, *, Paulo J. Tavares a , Jorge Belinha a,b , P. M. G. P. Moreira a a INEGI, Institute of Science and Innovation in Mechanical and Industrial Engineering, Dr. Roberto Frias Street, 400, 4200-465, Porto, Portugal. b FEUP, Faculty of Engineering, University of Porto, Dr. Roberto Frias Street, 4200-465, Porto, Portugal. This study m inly aims to determine th stress intensity fact range (SIF) for a compact tension (CT) spec men under uniaxial tensile fatigue loading state. A 2D full-field optical technique, Digital Image Correlation (DIC), is used to acquire the experimental solution. Therefore, the deformation contour is measured for several crack growth lengths. In addition, SIF is experimentally characterized together with a numerical overdetermined algorithm for different crack lengths. Besides, the strain variation with respect to the notch tip is captured. The innovation of this study is the combination of an experimental DIC procedure with a numerical overdetermined algorithm. Moreover, to assess the performance of the proposed fracture model, the problem is resolved using advanced discretization techniques, such as the Finite Element Method (FEM) and the Meshless Radial Point Interpolation Method (RPIM). Thus, the cracked CT specimen is elasto-statically modeled using above-mentioned numerical approaches. Hence, the FEM model is analyzed with ABAQUS ©, allowing to compute the mode I SIF results for different crack lengths in addition to strain contours. Likewise, the foregoing procedure is rep ated for the RPIM analysis and ncouraging numerical results are achi ved. The SIF is determined with a maximum energy release rate criterion n front of he crack tip in FEM study, while in RPIM study, it is calculated w thin the same ov rdetermined algorithm used in he DIC study. Overall, the experimental and num rical SIF results are compared with the reported solution (ASTM E647) ex ibiting a reas nable agree ent. © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017. 2nd International Conference on Structural Integrity, ICSI 2017, 4-7 September 2017, Funchal, Madeira, Portugal A Fracture Mechanics Study of a Compact Tension Specimen: Digital Image Correlation, Finite Element and Meshless Methods Behzad V. Farahani a,b, *, Paulo J. Tavares a , Jorge Belinha a,b , P. M. G. P. Moreira a a INEGI, Institute of Science and Innov t on in Mechanical nd Ind strial Engine ri g, Dr. Roberto Frias Street, 400, 4200-465, Porto, Po tugal. b FEUP, Faculty of Engineering, University of Porto, Dr. Roberto Frias Street, 4200-465, Porto, Portugal. Abstract This study mainly aims to determine the stress intensity factor r nge (SIF) for a compact tension (CT) specimen under uniaxi l tensile fatigue loading stat . A 2D full-field optical technique, Digital Image Correlation (DIC), is used t acquire the experimental solution. Therefore, the deformation contour is measured f r several crack growth lengths. In ad ition, SIF is experimentally chara terized toget er with n merical overdetermined algorithm for different crack lengths. Besid s, the strain variation with respect to the notch tip is captured. The innovation of this study is the c mbination of an experi ental DIC procedure with a numerical ov rdetermined algorit m. Moreover, to assess the p rformance f the proposed fracture model, the pr blem is resolved using advanced discretization techniques, such as the Finite Element Method (FEM) and the Meshless Radial Point Int rpolation Method (RPIM). Thus, th cracked CT specimen is elasto-statically modeled using above-mentioned numerical approaches. Hence, the FEM model is analyzed with ABAQUS ©, allowing to compute the mode I SIF results for different crack lengths in addition to strain contours. Likewise, the foregoing procedure is repeated for the RPIM analysis and encouraging numerical results are achieved. The SIF i etermined with a m ximum energy rele se rate criterion i front of the crack tip in FEM study, while in RPIM study, i is calcul ted within the same over etermined algorithm used in the DIC study. Overall, th experim n al and numer cal SIF results are compared with the r ported solution (ASTM E647) xhibit ng a reasonabl agreement. © 2017 The Au hors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committe of ICSI 2017. © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017 2nd International Conference on Structural Integrity, ICSI 2017, 4-7 September 2017, Funchal, Madeira, Portugal Abstract

© 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: Compact Tension Specimen; SIF range; FEM; RPIM; Fracture Mechanics. Keywords: Compact Tension Specimen; SIF rang ; FEM; RPIM; Fracture Mechanics.

Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation.

* Corresponding author. Tel.: +351 225082151. E-mail address: behzad.farahani@fe.up.pt * Correspon ing aut or. Tel.: +351 225082151. E-mail address: behzad.farahani@fe.up.pt

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. 2452-3216  2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017 10.1016/j.prostr.2017.07.113 * Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452 3216 © 2017 Th Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017. 2452-3216 © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017.