PSI - Issue 2_A

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com cienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Struc ural Integrity 2 (2016) 1071–1076 Available online at www.sciencedirect.com ScienceDirect StructuralIntegrity 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 Damage evolution in metals under the gigacycle fatigue loading due to the contact with surface-active liquid Mikhail V. Bannikov a , *, Oleg B. Naimark a a ICMM UB RAS, Academika Koroleva st.,1, Perm 614013, Russia The Rehbinder effect (adsorption strength reduction effect) consists in a qualitative change of the development of multi-scale damage kinetics in a deformed sample in the prese ce of surfactants (in our case, liqui gallium). Its influence on the fatigue life of pure iron under gigacycle loading conditions is associated with a qualitative change of the role of the surface. The property of the surface to serve as a high power "sink" for defects is significantly reduced due to similarity of the chemical potential of the solid and surfactant as a result of "filling" the incomplete atomic planes ,which provides the "adiabatic" character of the process of damage accumulation in the volume of material. Fatigue tests of pure iron were carried out on the ultrasonic resonant fatigue machine Shimadzu USF-2000 with frequency of 20 kHz in the gigacycle fatigue loading regime with very low stress amplitude, during which the material failur occurs er realization of 10 9 lo ding cycles. Fractured urfaces were a alyzed by optical and electron c microscopes to id ntify the depth of penetration of liquid metal into the fractur area. It has be n shown that the durability and strength of t e material co ing into contact with a surfactant are signific ntly r duce on the "adiabatic" surface and the r gion of l calization of the defect densi y is shifted to the surface layer, which is characteristic of "e brittlement" materials being in contact with a surf ct t. The Rehbin er effect radically chan es the mechanism of ack initiation in gigacycle fatigue regime, which le ds to the formation of cra ks in the surface layer of the sample, r ther than in the volume of the m terial, which is characteristic of this kind of fatigue failure. © 2016 The Au hors. Published by El evier B.V. Peer-review under responsibility of the Scientific Committe of ECF21. a , a ft s i d r 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. Abstract

© 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: Fractograp y, gigacycle fatigue,Rehbinder effect, liquid metal embrittlement.

Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation.

* Corresponding author. Tel.: +7-(342)-2378312. E-mail address: mbannikov@icmm.ru

* 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 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.2016.06.137