PSI - Issue 3

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 Structu al Integrity 3 (2017) 316–325 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2017) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2017) 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. 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 Monitoring the mechanical response of asymmetrically fractured marble epistyles after restoring their structural integrity Stavros K. Kourkoulis* and Ioanna Dakanali Laboratory of Testing and Materials, School of Applied Mathematical and Physical Sciences, Department of Mechanics, National Technical University of Athens, Zografou Campus, 157 73 Athens, Greece Abstract An experimental protocol is presented aiming to monitor the mechanical response of restored structural elements of marble monuments. An accurate copy of a typical epistyle of the Athens Parthenon Temple was constructed by experienced technicians of the Parthenon’s worksite under a 1:3 scale. It was composed by two asymmetric fragments and it was restored with the aid of three pairs of titanium bars. It was subjected to ten-point bending, in an attempt to simulate uniform loading conditions. Various techniques, both innovative and traditional ones, were used to monitor strains and displacements: Acoustic Emission (AE), Pressure Stimulated Currents (PSC), Digital Image Correlation (DIC), Optical Fibers, clip gauges, dial gauges and LVDTs. The data recorded from all techniques were in very good mutual agreement. What is more important, however, is that the AE and PSC techniques provided clear and mutually compatible data which can be safely considered as indicators of upcoming failures. © 2017 The Authors. Published by Elsevier B.V. Peer-review und r responsibility of the Scie tific Committee of IGF Ex-Co. Keywords: Marble monuments; truc ural integrity; ep styles; acoustic emission; igital image correlati ; asymmetrical fault. 1. Introduction The unique cultural value of ancient monuments renders continuous health monitoring of any restored structural element of them one of the most serious problems of engineers working in conservation/restoration projects. The nature of these structures imposes a series of limitations to the sensors that can be used for this purpose. For example, the materials used to attach the sensors should not cause any kind of damage to the material of the monuments while for XXIV Italian Group of Fracture Conference, 1-3 March 2017, Urbino, Italy Monitoring the mechanical response of asymmetrically fractured marble epistyles after restoring their structural integrity Stavros K. Kourkoulis* and Ioanna Dakanali Laboratory of Testing and Materials, School of Applied Mathematical and Physical Sciences, Department f Mechanics, Natio al Technical University of Athens, Zografou Campus, 157 73 Athens, Greece Abstract An experimental protocol is presented aiming to monitor the mechanical response of restored structural elements of marble monuments. An accurate copy of a typical epistyle of the Athens Parthenon Temple was constructed by experienced technicians of the Parthenon’s worksite under a 1:3 scale. It was composed by two asymmetric fragments and it was restored with the aid of three pairs of titanium bars. It was subjected to ten-point bending, in an attempt to simulate uniform loading conditions. Various techniques, both innovative and traditional ones, were used to monitor strains and displacements: Acoustic Emission (AE), Pressure Stimulated Currents (PSC), Digital Image Correlation (DIC), Optical Fibers, clip gauges, dial gauges and LVDTs. The data recorded from all techniques were in very good mutual agreement. What is more important, however, is that the AE and PSC techniques provided clear and mutually compatible data which can be safely considered as indicators of upcoming failures. © 2017 The Authors. Published by Elsevier B.V. Peer-revi w under responsibility of the Scientific Committee of IGF Ex-Co. Keywords: Marble monuments; structural integrity; epistyles; acoustic emission; igital image correlation; asymmetrical fault. 1. Introduction The unique cultural value of ancient monuments renders continuous health monitoring of any restored structural element of them one of the most serious problems of engineers working in conservation/restoration projects. The nature of these structures imposes a series of limitations to the sensors that can be used for this purpose. For example, the materials used to attach the sensors should not cause any kind of damage to the material of the monuments while for © 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 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 © 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.2017.04.059