PSI - Issue 13

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com ScienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structural Integrity 13 (2018) 2158–2163 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 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. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. ECF22 - Loading and Environmental effects on Structural Integrity Diffuse instability of slightly disordered quasi rate-independent anisotropic viscoplastic FCC-polycrystals Milan Micunovic 1 *, Ljudmila Kudrjavceva 2 1 Faculty of Engineering Sciences, UNIVERSITY OF KRAGUJEVAC, Kragujevac, Serbia 2 Department of Civil Engineering, STATE UNIVERSITY OF NOVI PAZAR, Novi Pazar, Serbia Abstract Geometry and kinematics of intragranular as well as intergranular plastic deformation of polycrystals are briefly discussed. Elastic strain is covered by h effective medium homogenization method inside a repres ntativ volume element (RVE). Evolution equation formed by tensor representation is derived from very simple micr -evolution equation. It has an incremental quasi rate-independent (QRI) form obtained by Vakulenko's concept of thermodynamic time. The rate dependence takes place by means of stress rate dependent value of the initial yield stress. In accordance with Zorawski’s communication about free macro rotations in intermediate reference onfiguration, strain geometry is based on constrained micro rotation within a representative volume element (RVE). The theory is applied to slightly disordered fcc-polycrystals. A comparison between QRI and classic diffuse instability equations is presented for transv rsely isotr pic poly ys als. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: Gradual instability, Anisotropy by damage and plasticity; Eshelbian implants; Thermodynamic time; 1. Introduction The following elements of t is short paper are important. a. Rabotnov's lay. A ncremental evolution equation accounts for diverse process speeds by means of dependence of initial yield stress on stress rate. Here the notion of Rabotnov's plastic strain initiation delay is employed. ECF22 - Loading and Environmental effects on Structural Integrity Diffuse instability of slightly disordered quasi rate-independent anisotropic viscoplastic FCC-polycrystals Milan Micunovic 1 *, Ljudmila Kudrjavceva 2 1 Faculty of Engineering Sciences, UNIVERSITY OF KRAGUJEVAC, Kragujevac, Serbia 2 Department of Civil Engin ering, STATE UNIVERSITY OF NOVI PAZAR, Novi Pazar, Serbia Abstract Geometry and kine atics of intragr nular as well a intergranular plastic deformation of polycrystals are briefly discussed. Elastic strain is covered by the effective medium homog nizat on method inside a representative volume element (RVE). Evol tion equ tion formed by t nsor repr senta on is derived from very simpl micro-evolution qua ion. It has an incr mental qua i rate- nd pendent (QRI) form obtain d by Vakulenko's concept of thermodynamic time. The rate dependence takes place by means of stress rate dependent value of the initi l yi ld stress. In accordance with Zorawski’s communicatio about fre macro rotations in inte medi r ference configuration, str in g ometry is based on constrained micro rotation within a representative volume eleme t (RVE). Th theory is appl ed to slightly dis rd red fcc-polycrystal . A comparison between QRI and classic diffuse instability equations is pr sented for transver ely isotropic polycrystals. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: Gradual instability, Anisotropy by damage and plasticity; Eshelbian implants; Thermodynamic time; 1. Introduction The following elements of this short paper are important. a. Rab tnov's delay. An ncremental evolution equation accounts for diverse process speeds by means of dependence of initial yield stress on stress rat . H re the notion of Rabotnov's plastic strain initiation delay is employed. © 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.: +381-65-3576530; E-mail address: milanmicunovic10@gmail.com * Corresponding author. Tel.: +381-65-3576530; E-mail ad ress: milanmicunovic10@gmail.com

* Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452-3216 © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. 2452-3216 © 2018 The Authors. Published by Elsevier B.V. Peer review under r sponsibility of the ECF22 o ganizers.

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016.

2452-3216  2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. 10.1016/j.prostr.2018.12.148