PSI - Issue 2_B

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) 2881–2888 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Available online at www.sciencedirect.com cience irect 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 The bi-material circular disc compressed between the jaws of the ISRM standardized apparatus for the Brazilian test Ch. F. Markides, E. D. Pasiou and S. K. Kourkoulis* Laboratory of Testing and Materials, Department of Mechanics, School of Applied Mathematical and Physical Sciences, National Technical University of Athens, 5, Heroes of Polytecnion Avenue, 15773 Athens, Greece The m chanical response f a circular bi-mat rial disc, squeezed betwee circular jaws, is studied numerically. The disc is compo ed by two identical (from the geometric point of view) almost semi-circ lar discs joined together with the aid of a thin layer of a third material. The numerical model is validated against experimental data obtained with the aid of Digital Image Correlation technique. The influence of various (geometric and material) parameters on the stress- and displacement-fields developed all over the composite disc is studied comparatively. Attention is paid to the role of the thickness and stiffness of the intermediate layer as it is quantified by its modulus of elasticity. The influence of the inclination of the interfacial layer (with respect to the axis of the load imposed) is also considered. It is concluded that the role of the interfacial layer is by no means negligible even in case its thickness is very small with respect to the disc radius. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: Bi-material disc; interface; Brazilian-disc test, Finite Element Method The study of the mechanical response of composite materials using the Brazilian disc test is advantageous mainly due to the simple geometry of the specimens and the fact that any orientation between the interface and the loading axis is easily achieved, by just rotating the specim n. Moreover the specific configuration is very flexible in case inter facial crack problem are to be studied (Banks-Sills, 2015; Banks-Sills and Schwartz, 2002; Banks-Sills et al., 2010). 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy he bi- aterial circular disc co pressed between the jaws of the IS standardized apparatus for the razilian test Ch. F. Markides, E. D. Pasiou and S. K. Kourkoulis* Laboratory of Testing and Materials, Department of Mechanics, School of Applied Mathematical and Physical Sciences, National Technical University of Athens, 5, Heroes of Polytecnion Avenue, 15773 Athens, Greece Abstract The mechanical response of a circular bi-material disc, squeezed between circular jaws, is studied numerically. The disc is composed by two identical (from the geometric point of view) almost semi-circular discs joined together with the aid of a thin layer of a third material. The numerical model is validated against experimental data obtained with the aid of Digital Image Correlation technique. The influence of various (geometric and material) parameters on the stress- and displacement-fields developed all over the composite disc is studied comparatively. Attention is paid to the role of the thickness and stiffness of the intermediate layer as it is quantified by its modulus of elasticity. The influence of the inclination of the interfacial layer (with respect to the axis of the load imposed) is also considered. It is concluded that the rol of th interfacial layer is by o means egli ible eve in case ts thickness is very small with respect to the disc radius. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: Bi-material disc; interface; Brazilian-disc test, Finite Element Method 1. Introduction The study of the mechanical response of composite materials using the Brazilian disc test is advantageous mainly due to the simple geometry of the specimens and the fact that any orientation between the interface and the loading axis is easily achieved, by just rotating the specimen. Moreover the specific configuration is very flexible in case inter facial crack problem are to be studied (Banks-Sills, 2015; Banks-Sills and Schwartz, 2002; Banks-Sills et al., 2010). Copyright © 2016 The Author . Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc- d/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. Abstract 1. Introduction

* 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.: +30-210-7721263; fax: +0030-210-7721302. E-mail address: stakkour@central.ntua.gr * Corresponding author. Tel.: +30-210-7721263; fax: +0030-210-7721302. E-mail address: stakkour@central.ntua.gr

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.2016.06.360