PSI - Issue 2_A

ScienceDirect Available online at www.sciencedirect.com Av ilable online at ww.sciencedire t.com ScienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Struc ural Integrity 2 (2016) 2424–2431 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2016) 000–000 Available online at www.sciencedirect.com Sci nceDirect 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 Dugdale's Model for Plastic Zone Size of Interacting Cracks under Anti-plane Deformation Alireza Hassani a , Reza Teymoori Faal a, * a Faculty of Engineering, University of Zanjan, P.O. Box 45195-313, Zanjan, Iran Abstract By means of the image method the solution of screw dislocation is obtained in an isotropic elastic layer. The solution is used to derive integral equations for a cracked layer subjected to anti-plane deformation. Based on the Dugdale's model the solution of these equations, are utilized to determine plastic zone size ahead of a crack tip. For the special case of a single crack in an infinite plane the plastic zone size was obtained analytically and validated by the available result in the literature. The results show that the interaction between the cracks leads to different sizes of the plastic zone for each of the crack tips. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywo ds: Anti-plane deformation; C ack tip plastic region; Dislocation density; Dugdale's model 1. Introduction A simple model to remove the stress singularity of the crack tip was proposed by Dugdale (1960) by introducing a line plastic z ne ahead of the crack. He proposed a closure model for a slit weakening a plate und r the Mode I deformation. The plastic zo es developed due to the far-field applied tension we e close by distributing yield point stress over the slit borders. The Dugdale's model approximates the actual shape of the plastic zone for cracks in thin steel plates subjected to plane stress loading conditions. An adequate attention has been paid on this regard in the literature. In what follows we review them briefly. Based on the Dugdale's model, the plastic zones near the tips of two collinear and unequal cracks within a homogeneous, isotropic, elastic-perfectly plastic infinite plate were computed by Theocaris (1983). The cracks were 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Dugdale's M d l for Plastic Zone Size of Interacting Cracks under Anti-plane Deformation Alireza Hassani a , Reza Teymoori Faal a, * a Faculty of Engineering, University of Zanjan, P.O. Box 45195-313, Zanjan, Iran Abstract By means of the image method the solution of screw islocation is obtained in an isotropic elastic layer. The solution is used to derive integral quations for a cracked layer subjected t nti-plane def rmation. Based on the Dugd le's model the solution of thes equations, are util d to determine pl stic zone size ahead f a crack tip. For th special case of a single crack in an infinite plane the plastic zon siz w s obtained analytically and validated by the available result in the literature. The results show that the interaction between the cracks leads to different sizes of the plastic zone for each of the crack tips. © 2016 The Autho s. Publ shed by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: Anti-plane deformation; Crack tip plastic region; Dislocation density; Dugdale's model 1. Introduction A simp e m d l to rem ve the stress singularity of the crack tip was proposed by Du d l (1960) by introducing a lin plastic zone ahead f the crack. He proposed a closure model for a slit weakenin a pla e under th Mode I deformation. The plastic zones develop d due to the far-field applied tension were closed by distributing yield poi t r ss ov r the slit borders. The Dugdale's model approximates the ctu l shape of the plastic z e for cracks in thin s el plates subjected to plane str ss loading conditions. An adequate attention has been paid on this regard in the liter ture. I w at follows we review them briefly. Based n the Dugdal 's mod l, the plastic zones near the tips of two collinear and unequal cracks within a homogeneous, isotropic, elastic-perfectly plastic infinite plate were computed by Theocaris (1983). The cracks were 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: 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 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. * Corresponding author. Tel.: +98 241 515 2600; fax: +98 241 515 2762. E-mail address: faal92@yahoo.com * Corresponding author. Tel.: +98 241 515 2600; fax: +98 241 515 2762. E-mail address: faal92@yahoo.com

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.2016.06.303