PSI - Issue 2_A

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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 Anisotropic discs loaded by parabolically distributed pressure Christos F. Markides, Stavros K. Kourkoulis* Laboratory of Testing and Materials, Department of Mechanics, National Technical University of Athens, Zogr fou Campus, 157 73 Athens, Greece Abstract The complex potentials which describe the elastic equilibrium of a circular disc made of a transversely isotropic, homogeneous material are presented. It is assumed that the disc is loaded by a parabolic distribution of radial stresses which act along two finite circular arcs, antisymmetric with respect to the disc’s center. The problem is here solved within the frame of linear elasticity assuming plane strain conditions. The complex potentials technique is adopted as it was formulated by Lekhnitskii in his pione ering contributions. When the complex potentials are determined, one can obtain the respective stress field developed all over the disc for any value of the angle between the axis of symmetry of pressure distribution and the planes of material isotropy. Attention is focused at the disc’s center and at the loaded diameter. Conclusions regarding the applicability of the Brazilian-disc test in case of specimens made of transversely isotropic materials are drawn. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: Anisotropic materials; Transverse isotropy; Brazilian-disc test; Complex potentials, Stress tensor 1. Introduction The Brazilian-disc test is the most convenient and widely used substitute of the direct tension test. It was initially introduced for isotropic materials (Carneiro 1943; Akazawa 1943; Hondros 1959). However, most rock-like materials exhibit some kind of anisotropy and therefore the applicability of existing solutions for stresses and displacements becomes questionable. The problem is usually confronted numerically (Dan & Konietzky 2014) or experimentally (Vervoort et al. 2014) since analytic solutions are very rare (Exadaktylos et al. 2001). In this context, an attempt to obtain such a solution is described here, using Lekhnitskii’s (1968, 1981) complex potential technique for rectilinear 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy nisotropic discs loaded by parabolically distributed pressure Christos F. arkides, Stavros K. Kourkoulis* Laboratory of Testing and Materials, Department of Mechanics, National Technical University of Athens, Zografou Campus, 157 73 Athens, Greece Abstract The complex potentials which describe the elastic equilibrium of a circular disc made of a transversely isotropic, homogeneous material are presented. It is assumed that the disc is loaded by a parabolic distribution of radial stresses which act along two finite circular arcs, antisymmetric with respect to the disc’s center. The problem is here solved within the frame of linear elasticity assuming plane strain conditions. The complex potentials technique is adopted as it was formulated by Lekhnitskii in his pione ering contributions. When the complex potentials are determined, one can obtain the respective stress field developed all over the disc for any value of the angle between the axis of symmetry of pressure distribution and the planes of material isotropy. Attention is focused at the disc’s center and at the loaded diameter. Conclusions regarding the applicability of the Brazilian-disc test in case of specimens made of transversely isotropic materials are drawn. © 2016 The Aut ors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: Anisotropic materials; Transverse isotropy; Brazilian-disc est; Compl x potentials, Stress tensor 1. Introduction The Brazilian-disc test is the most convenient and widely used substitute of the direct tension test. It was initially introduced for isotropic materials (Carneiro 1943; Akazawa 1943; Hondros 1959). However, most rock-like materials exhibit some kind of anisotropy and therefore the applicability of existing solutions for stresses and displacements becomes questionable. The problem is usually confronted numerically (Dan & Konietzky 2014) or experimentally (Vervoort et al. 2014) since analytic solutions are very rare (Exadaktylos et al. 2001). In this context, an attempt to obtain such a solution is described here, using Lekhnitskii’s (1968, 1981) complex potential technique for rectilinear Copyright © 2016 The Author . Published by Elsevier B.V. This is a open ac ess ar icle under the CC BY-NC-ND license (http://creativecommons.org/licens s/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.: +30-210-7721263; fax: 30-210-7721302. E-mail address: stakkour@central.ntua.gr * Corresponding author. Tel.: +30-210-7721263; fax: 30-210-7721302. 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.2016.06.332