PSI - Issue 3

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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. Copyright © 2017 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 IGF Ex-Co. XXIV Italian Group of Fracture Conference, 1-3 March 2017, Urbino, Italy The di placement field in an orthotropic disc under parabolic pressure. Application to the case of transverse isotropy Christos F. Markides, Stavros K. Kourkoulis* National Technical University of Athens, School of Applied Mathematical and Physical Sciences, Department of Mechanics, 5 Heroes of Polytechnion Avenue, Theocaris Bld., Zografou Campus,157 73 Athens, Greece Abstract Αn analytic solution for the displacement field developed in a circular disc made of an orthotropic material is presented assuming that the disc is loaded by a distribution of radial stresses varying according to a parabolic law and acting along two finite arcs of the disc’s periphery, antisymmetric with respect to its center. The solution is achieved with the aid of the complex potentials technique for rectilinear anisotropic materials as it was formulated by Lekhnitskii. The complex potentials and the general ex pressions for the displacement components are obtained at any point of the disc for the general case of orthotropy and then they are particularized for a transversely isotropic disc, due to its increased importance in practical engineering applications. © 2017 The Authors. Publishe by Elsevier B.V. Peer-review under res on ibility of the Scientific Committee of IGF Ex-Co. Keywords: Orthotrop c Disc; Transversely i otropic disc; Pa ab lic pressure; C mplex otentials; Displacement field 1. Introduction The determination of the limiting strength of rock-like materials under tensile loading is a demanding, non-trivial task, especially in case the material tested is of anisotropic nature. For such materials tensile strength is not a unique constant but rather it is a function of the orientation of the loading axis with respect to the anisotropy axes. The expe rimental determination of this function is achieved (almost exclusively) with the aid of the Brazilian-disc test, i.e. the diametral compression of cylindrical discs either between curved or plane jaws. The specific test was initially proposed as a c nven ent substitute of the dir ct tension test. It is to be mentioned, however, that the underlying theoretical principles for the stress field at the center of a circular disc under diametral compression (either by point forces or uniformly distributed pressure) are valid exclusively for linearly elastic, isotropic materials. Clearly, these assumptions XXIV Italian Group of Fracture Conference, 1-3 March 2017, Urbino, Italy The displacement field in an orthotropic disc under parabolic pressure. Application to the case of transverse isotropy Christos F. Markides, Stavros K. Kourkoulis* National Technical University of Athens, School of Applied Mathematical and Physical Sciences, Department of Mechanics, 5 Heroes of Polytechnion Avenue, Theocaris Bld., Zografou Campus,157 73 Athens, Greece Abstract Αn analytic solution for the displaceme t field developed in a circular disc made of an orthotropic material is presented assuming that the dis is oaded by a distribution of radial stresses varying according to a parabolic law and acting along two finite arcs of the disc’s periphery, antisymmetric with respect to its center. The solution is achieved with the aid of the complex potentials technique for rectiline r anisotropic ma erial as it wa formulated by Lekhn tskii. Th complex potentials and the general ex pressions for th d splacement c mponents re obtained at any point of th disc for the general case of orthotropy and th n th y are particularized for a transversely is tropic disc, due to its increased importance in practical engine ring applications. © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of IGF Ex-Co. Keywo ds: Orthotropic Disc; Tran vers ly isotropic disc; Parabolic pr ssure; Complex potentials; Displacement field 1. Intro uction The determination of the limiting strength of rock-like materials under tensile loading is a emanding, non-trivial task, especially in case the material te ed is of anisotropic n u e. For such materials te sile str ngth is not a unique constant but rather it is a function of he orientation f the loading axis with respect to the aniso opy axes. The expe riment l determinat on of this function is achieved (almost exclusively) the aid of Brazilian-disc test, i.e. th d ametr compression of cylindrical disc eit er between curved or plane jaws. The specific test was init ally proposed as convenient substitute of the direct tension tes . It is to b mentio ed, however, that th underly ng theoretical principles for the stress fi ld a the c n er of a circular disc under diam tr l compression (either by point forc s or un form y distributed pressure) re valid exclusively for linearly elastic, isotropi aterials. Cl arly, these assumptions © 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 © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of IGF Ex-Co. 2452-3216 © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of IGF Ex-Co. * Corresponding author. Tel.: +30 210 772 1263; fax: +30 210 772 1264. E-mail address: stakkour@central.ntua.gr * Corresponding author. Tel.: +30 210 772 1263; fax: +30 210 772 1264. 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 © 2017 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 IGF Ex-Co. 10.1016/j.prostr.2017.04.024