PSI - Issue 13

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at www.sciencedire t.com ienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structural Integrity 13 (2018) 2011–2 16 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. ECF22 - Loading and Environmental effects on Structural Integrity Dispersion of graphene nanoplatelets reinforcing type II cement paste Zoi S. Metaxa a,b, * , Stavros K. Kourkoulis a a Laboratory of Testing and Materials, National Technical University of Athens, 9 Heroes Polytechniou Str., 15780 Athens, Greece b Hephaestus Laboratory, Eastern Macedonia and Thrace Institute of Technology, Agios Loukas, 65404, Kavala, Greece Abstract One of the most recent, affordable and at the same time cutting-edge class of carbon nanostructures are the graphene nanoplatelets (GnPs). They depict multifunctional capabilities such as improved mechanical properties in conjunction with high electrical and thermal conductivity making them suitable for the development of multifunctional materials. One of the most essential parameters, to successfully exploit the GnPs characteristics, is their homogeneous distribution inside the matrix. In this direction, the applicability of a method, similar to the one applied for the preparation of carbon nanofiber and carbon nanotube reinforced Type I cement nanocomposites, is here investigated. Ultrasonic processing and treatment with a 3 rd generation superplasticizer was used to uniformly disperse the GnPs (of lateral size equal to 8 μm ) in the mixing water. This admixture was exploited as a GnPs dispersing agent, as it is commonly used, to improve the workability of cementitious materials and is fully compatible with the matrix. The nanocomposites were prepared using Type II cement. The electrical resistivity of the nanocomposites developed was evaluated. Three-point bending tests were performed at prismatic beam specimens with an artificial notch at the age of 28 days. Both the effects of dispersing agent (superplasticizer) concentration and ultrasonication energy application were investigated. It was concluded that both the admixture concentration and ultrasonic energy application strongly affect the GnPs dispersion and reinforcing efficiency. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: Graphene nanoplatelets; dispersion; type II cement; mechanical performance; electrical resistivity © 2018 The Aut ors. Published by Elsevier B.V. Peer-review und r responsibility of the ECF22 organizers. ECF22 - Loading and Environmental effects on Structural Integrity Dispersion of graphene nanoplatelets reinforcing type II cement paste Zoi S. Metaxa a,b, * , Stavros K. Kourkoulis a a Laboratory of Testing and Materials, National Technical University of Athens, 9 Heroes Polytechniou Str., 15780 Athens, Greece b Hephaestus Laboratory, Eastern Macedonia and Thrace Inst ute of T chnology, Agios Loukas, 65404, Kavala, Greece Abstract One of the most recent, affordable and at the same time cutting-edge class of carbon nanostructures are the graphene nanoplatelets (GnPs). They depi t multifunction l capabilities such as improved mechanical properties in conjunction with igh electric l and thermal conductivity making them suitable for the development f multifunctional mat rials. One of the most essential parameters, to successfully exploit the G Ps racteristics, is their homogen us distributi in e the matrix. In this directio , the applicability of a method, similar to the one applied for the preparati n of ca bon nanofiber and carbon nanotube reinforced Type I ement nanocomposites, is here investigated. Ultrasonic processing and treatment with a 3 rd ge erati n superplasticizer was used to unif rmly disperse the GnPs (of lateral size equal to 8 μm ) i the mixing water. T is admixture was exploited as a GnPs dispersing agent, as it is commonly used, to improv the workability of c entitious materials and is fully com atible with the matrix. The nanocomposites were prepared using Type II cement. The electrical resistivity of the nanocomposites developed was evaluated. Three-point bending tests wer performed at prismatic beam sp imens with an artificial notch at the ag of 28 days. Both the effects of dispersing agent (superplasticizer) concentration and ultrasonication energy ppli ation were investigated. It was c ncluded that both the admixture conc ntr tion and ultrasonic energy application strongly affect the GnPs dispersion and reinforcing efficiency. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: Graphene nanoplatelets; dispersion; type II cement; mechanical performance; electrical resistivity

© 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. 1. Introductio 1. Introduction

Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation. Graphene nanoplat lets (GnPs) have received considerable attention in the recent years as they are quite affordable and at the same time they demonstrate excellent mechanical and electrical characteristics. Due to their exceptional Graphene nanoplatelets (GnPs) have received considerable attention in the recent years as they are quite affordable and at the same time they demonstrate excellent mechanical and electrical characteristics. Due to their exceptional

* 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 organizers. * Corresponding author. Tel.: +30-210-7721310; fax: +30-210-7721264. E-mail address: zmetaxa@central.ntua.gr * Corresponding author. Tel.: +30-210-7721310; fax: +30-210-7721264. E-mail ad ress: 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.

2452-3216  2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. 10.1016/j.prostr.2018.12.215