PSI - Issue 2_A

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ScienceDirect Available online at www.sciencedirect.com Av ilable o line at www.sciencedire t.com cienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Struc ural Integrity 2 (2016) 3423–3431 StructuralIntegrity Procedia 00 (2016) 000–000 StructuralIntegrity Procedia 00 (2016) 000–000 ScienceDirect StructuralIntegrity Procedia 00 (2016) 000–000 ScienceDirect

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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 Fracture analysis of a cracked orthotropic strip bonded to a magneto electro-elastic layer M. Nourazar, M. Ayatollahi*, J. Miandari, S. Varasteh Faculty of Engineering, University of Zanjan, P.O. Box 45195-313, Zanjan, Iran The problem of a magneto-electro-elastic coating bonded to an orthotropic strip with multiple cracks is analyzed. The problem is solved under anti-plane shear and in-plane el tric and magn tic loading. First, an analytical solution is developed considering a single dislocation problem. Fourier transforms are applied to reduce problem to system of singula integral equations, in which the unknown variables are dislocation densities. The integral equations are of the Cauchy singular kinds which are solved to determine stress intensity factors at the crack tips. The results show that the stress intensity factors at the crack tips as influenced by the imperfect bonding coefficient, the crack geometry and material properties of the orthotropic substrate © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywo ds: Magneto-electro-elastic coating; Multiple cracks; Imperfect bonding; orthotropic layer; Stress intensity factors; 1. Introduction The concept of magneto-electro-elastic material h s been introduced in coating design as an alternative to the conventional coatings. To gain advanced performance, piezoelectric-piezomagnetic components are often made as layered structures. Layered structures made of piezomagnetic materials exhibit magneto ectric effect t at is not pres nt in si gle phase piezoelect ic or piezom gnetic materials. Therefore, it is necessary to advance our underst nding of the ch racteristics of magneto-electro-ela ti coating with cracked substrate. Orthotropic compos t s are sometimes used as the substrate of layered piezoelectric/piezomagnetic devices to enhance mechanical performance. Song and Sih (2003) investigated the crack initiation behaviour in a magneto-electro- lastic composite under in-plane deformation. Exact treatment on the crack problems in magneto electro-elastic solids is considered by Gao et al. (2003). The anti-plane shear crack problem in an infinite piezoelectromagnetic medium using complex variable method is investigated by Wang and Mai (2005). Wang et al. (2006) considered the crack facing electromagnetic boundary conditions of a crack in a agneto-electro-elastic layer. Zhou et al. (2007) analyzed mode I crack problem in an infinite electromagnetic medium assuming magneto electrically permeable crack surfaces. Tian and Rajapakse (2008) gave a fracture analysis of crack branching in magneto-electro-elastic solids by extending the generalized dislocation model. The problem of FGPM coating containing a permeable crack under anti-plane loading with a Kelvin-type viscoelastic interface have been solved by Cheng and Zhao (2009). Peng and Li (2009) studied the interface crack problem for homogeneous magneto-electro-elastic substrate with a functionally graded coating. The mode III crack problems in a functionally graded 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Fracture analysis of a cracked orthotropic strip bonded to a magneto electr -elastic layer M. Nourazar, M. Ayatollahi*, J. Miandari, S. Varasteh Faculty of Engineering, University of Zanjan, P.O. Box 45195-313, Zanjan, Iran Abstract The problem of a magneto-electro-elastic coating bonded to an orthotropic strip with multiple cracks is analyzed. The problem is solved under anti-plane shear and in-plane electric and magnetic loading. First, an analytical solution is developed considering a single dislocation problem. Fourier transforms are applied to reduce problem to system of singular integral equations, in which the unknown variables are dislocation densities. The integral equations are of the Cauchy singular kinds which are solved to determine stress intensity factors at the crack tips. The results show that the stress intensity factors at the crack tips as influenced by the imperfect bonding coefficient, the crack geometry and material properties of the orthotropic substrate © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: Magneto-electro-elastic coating; Multiple cracks; Imperfect bonding; orthotropic layer; Stress intensity factors; 1. Introduction The concept of magneto-electro-elastic materials has been introduced in coating design as an alternative to the conventional coatings. To gain advanced performance, piezoelectric-piezomagnetic components are often made as layered structures. Layered structures made of piezomagnetic materials exhibit magnetoelectric effect that is not present in single phase piezoelectric or piezomagnetic materials. Therefore, it is necessary to advance our understanding of the characteristics of magneto-electro-elastic coating with cracked substrate. Orthotropic composites are sometimes used as the substrate of layered piezoelectric/piezomagnetic devices to enhance mechanical performance. Song and Sih (2003) investigated the crack initiation behaviour in a magneto-electro-elastic composite under in-plane deformation. Exact treatment on the crack problems in magneto electro-elastic solids is considered by Gao et al. (2003). The anti-plane shear crack problem in an infinite piezoelectromagnetic medium using complex variable method is investigated by Wang and Mai (2005). Wang et al. (2006) considered the crack facing electromagnetic boundary conditions of a crack in a magneto-electro-elastic layer. Zhou et al. (2007) analyzed mode I crack problem in an infinite electromagnetic medium assuming magneto electrically permeable crack surfaces. Tian and Rajapakse (2008) gave a fracture analysis of crack branching in magneto-electro-elastic solids by extending the generalized dislocation model. The problem of FGPM coating containing a permeable crack under anti-plane loading with a Kelvin-type viscoelastic interface have been solved by Cheng and Zhao (2009). Peng and Li (2009) studied the interface crack problem for homogeneous magneto-electro-elastic substrate with a functionally graded coating. The mode III crack problems in a functionally graded 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Fracture analysis of a cracked rthotropic strip bonded to a agneto electro-elastic layer M. Nourazar, M. Ayatollahi*, J. Miandari, S. Varasteh Faculty of Engineering, University of Zanjan, P.O. Box 45195-313, Zanjan, Iran Abstract The problem of a magneto-electro-elastic coating bonded to an orthotropic strip with multiple cracks is analyzed. The problem is solved under anti-plane s ar and in-plane elect ic and magnetic loading. First, an analytical soluti n is developed considering a single dislocation problem. Fourier transforms are applied to reduce problem to system of ingular integral equations, in which the unknown variables ar dislocation densities. Th integral equa i ns are of the Cauchy singular kinds which are solved to determine stress intensity factors at the crack tips. The results show that the stres intensity factors at the crack tips as influenced by the imperfect bonding coefficient, the crack geometry and material properties of the orthotropic substrate © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Com ittee of ECF21. Keywords: Magneto-electro-elastic coating; Multiple cracks; Imperfect bonding; orthotropic layer; Stress intensity factors; 1. Introduc i n The concept of magn to-electro-elastic materials has been introduced in coating design as an alternative to the c nv nt onal coatings. To gain adv nced per mance, piezoelectric-piezomagnetic components are often made as layered structures. Layered structures made of piezomagne ic materials exhibit magnetoel ctric ffect that is not present in single phase piez electric or magnetic materials. Ther fore, it is necessary to dvance our understanding of the characteristic of magneto-electro-el stic coating with cracked substr te. Orth tropic com osit s are sometimes used as the substrate of lay red piezoel ctric/piezomagnetic vices to enhance mechanical performance. Song and Sih (2003) i vestigated the crack initiation behaviour i a magneto-electro-elas ic composite under in-plane deform tion. Exact treatment on the rack problems in magneto tr -elastic solids is considered by Gao et al. (2003). Th anti-plane shear crack problem in an infinite pie oelectromagnetic mediu using compl x variable method is investigated by W ng and Mai (2005). Wang et al. (2006) considered the crack facing electrom gnetic bo ndary conditions of a cra k in a magneto-electro-elastic layer. Zhou e al. (2007) analyzed mode I crack pr blem in an infinite electromagnetic medium assuming magneto electrically perm able crack surf ces. Tian and Rajapakse (2008) gave a fracture anal sis of cr ck br nching in ma neto-electro-elastic solids by extending the generalized dislocation odel. The p blem of FGPM coating containi g a pe m able crack under anti-plane loading with a Kelvin-type viscoelastic interface have been solved by Cheng and Zhao (2009). Peng and Li (2009) studied the interface crack problem for homogeneous magneto-electro-elastic substrate with a functionally graded coating. The mode III crack problems in a functionally graded 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-revie u der resp nsibility of the Scientific o ittee 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. Abstract

* Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt * Corresponding author. Tel: +98-24-3305-2488; fax: +98-24-3305-2762 E-mail address: mo.ayatollahy@gmail.com(M. Ayatollahi). 2452-3216© 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. * Corresponding author. Tel: +98-24-3305-2488; fax: +98-24-3305-2762 E-mail address: mo.ayatollahy@gmail.com(M. Ayatollahi). * Corresponding author. Tel: +98-24-3305-2488; fax: +98-24-3305-2762 E-mail address: mo.ayatollahy@gmail.com(M. Ayatollahi).

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.2016.06.427 2452-3216© 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. 2452-3 16© 2016 The Authors. Publi hed y Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21.