PSI - Issue 2_A

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ScienceDirect Available online at www.sciencedirect.com Av ilable o line at www.sciencedire t.com cienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Struc ural Integrity 2 (2016) 2833–284 ScienceDirect Structural Integrity Procedia 00 (2016) 000–000 ScienceDirect Structural Integrity 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 Carbon nanotube reinforced mortar as a sensor to monitor the structural integrity of restored marble epistyles under shear Z.S. Metaxa a *, E.D. Pasiou a , I. Dakanali a , I. Stavrakas b , D. Triantis b , S.K. Kourkoulis a a Laboratory of Testing and Materials, Department of Mechanics, National Technical University of Athens, Zografou Campus, 157 73 Athens, Greece b Department of Electronics, Technological Educational Institution of Athens, 122 10 Athens, Greece Abstract Metallic “I”-shaped connectors, properly placed in sculptured grooves, are used nowadays for restoring damaged connections of the Parthenon Temple. The grooves are then filled with a suitable cement mortar. In this study, the mortar was reinforced with multi walled carbon nanotubes, in an effort to develop a smart material which could monitor the structural integrity of the connection, by measuring its electrical resistance through the Electrical Resistance Change (ERC) technique. The connection was subjected to shear using a properly designed metallic restraining-loading system. The ERC technique was used in conjunction with traditional (electrical strain gauges and clip gauges) and innovative sensing techniques (Digital Image Correlation and Acoustic Emission). The data obtained by the ERC technique are in very good qualitative agreement with the respective ones provided by both the traditional and the innovative techniques. Moreover, the overall variation of the ERC is well compatible with the load applied, indicating that the specific quantity could be a flexible tool for monitoring strain/damage of the restored connections. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: Monuments; Restoration; Multi-Walled Carbon Nanotubes; Shear; Epistyles’ Connection; Marble; Cement Mortar Nanocomposites 1. Introduction The monuments constructed during the classical era (5 th -4 th century BC) were built using stone blocks without any intermediate layer of adhesive material. Typical monuments of these dry stone constructions are the ones of the Athenian Acropolis. They were built using Pentelic marble blocks which were connected to each other by means of 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Carbon nanotube reinforced mortar as a sensor to monitor the structural integrity of restored marble epistyles under shear Z.S. Metaxa a *, E.D. Pasiou a , I. Dakanali a , I. Stavrakas b , D. Triantis b , S.K. Kourkoulis a a Laboratory of Testing and Materials, Department of Mechanics, National Technical University of Athens, Zografou Campus, 157 73 Athens, Greece b Department of Electronics, Technological Educational Institution of Athens, 122 10 Athens, Greece Abstract Metallic “I”-shaped connectors, properly placed in sculptured grooves, are used nowadays for restoring damaged connections of the Parthenon Temple. The grooves are then filled with a suitable cement mortar. In this study, the mortar was reinforced with multi walled carbon nanotubes, in an effort to develop a smart material which could monitor the structural integrity of the connection, by measuring its electrical resistance through the Electrical Resistance Change (ERC) technique. The connection was subjected to shear using a properly designed metallic restraining-loading system. The ERC technique was used in conjunction with traditio al (electrical strain gauges and clip gauges) and innovative sensing t chniques (Digital Image Correlation a d Acoustic Emission). The data obtained by the ERC technique are in very good qualitative agreement with the respective ones provided by both the traditional and the innovative technique . Moreover, th overall variation of the ERC is well compatible with the loa appli d, indicating that the specific quantity coul be a flexible tool for monitoring str n/d mage of the restored conn tions. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: Monuments; Restoration; Multi-Walled Carbon Nanotubes; Shear; Epistyles’ Connection; Marble; Cement Mortar Nanocomposites 1. Introduction The monuments constructed during the classical era (5 th -4 th century BC) were built using stone blocks without any inte med ate layer of adhesiv material. Typical monuments f these dry stone constructions are the ones of the Athenian Acropolis. They were built using Pentelic marble blocks which were connected to each other by means of Copyright © 2016 The Author . Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc- d/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.: +30-210-772-1310; fax: +30-210-772-1302. E-mail address: zmetaxa@central.ntua.gr * Corresponding author. Tel.: +30-210-772-1310; fax: +30-210-772-1302. E-mail address: zmetaxa@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.2016.06.354