PSI - Issue 12

ScienceDirect Available online at www.sciencedirect.com Available o line at www.sciencedire t.com ScienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structural Integrity 12 8 44–51 Available online at www.sciencedirect.com ScienceDirect StructuralIntegrity Procedia 00 (2018) 000 – 000 Available online at www.sciencedirect.com ScienceDirect StructuralIntegrity 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. AIAS 2018 International Conference on Stress Analysis Experimental investigation about tribological performance of grapheme-nanoplatelets as additive for lubricants Francesca Curà a, * , Andrea Mura a , Federica Adamo a a Department of Mechanical and Aerospace Engineering, Politecnico di Torino, corso Duca degli Abruzzi 24, Torino, Italy Graphene has received a great interest by researchers in a wide field of applications. Referring to tribological aspects, graphene has been considered as an additive in lubricants, in order to reduce components friction and machine losses. Some papers are available in literature about graphene utilized as additive in solids or liquid lubricants. Despite the big potential of graphene in this field, its use as a lubricant or a lubricant additive on macro-meso scale remains relatively unexplored. In particular, the literature is lacking about specific applications of graphene added lubricants on mechanical systems. In this paper, the effect graphene added to a standard lubricants to create high performance compounds has been investigated. Firstly, the Coefficient of Friction (CoF) of different compositions of lubricant-graphene compounds has been experimentally evaluated. In particular, a commercial grease and two commercial oils have been chosen to be used as base lubricants. Results in terms of Coefficient of Friction values of all compounds have been compared each other. Finally, characterization results of graphene added grease have been related to that available from previous studies performed on a mechanical component (a spline coupling), commonly used in many industrial applications, lubricated by the same graphene grease compounds. Results show that graphene added to viscous lubricants generally reduces the coefficient of friction, in both materials and components. © 2018 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/3.0/) Peer-review under responsibility of the Scientific Committee of AIAS 2018 International Conference on Stress Analysis. © 2018 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/3.0/) Peer-review under responsibility of the Scientific Committee of AIAS 2018 International Conference on Stress Analysis. AIAS 2018 International Conference on Stress Analysis Experimental investigation about tribological performance of grapheme-nanoplatelets as additiv fo lubric nts Francesca Curà a, * , Andrea Mura a , Federica Adamo a a Department of Mechanical and Aerospace Engineering, Politecnico di Torino, corso Duca degli Abruzzi 24, Torino, Italy Abstract Graphene has received a great interest by researchers in a wide field of applications. Referring to tribological aspects, graphene has be con ider d as n addit ve in lu ricants, in order to re uce components friction and machine losses. Some papers are available in l erature about graphene utiliz d as additive i solids r liquid lubr cants. Despite the big potential of graphen in this field, its use as lubricant or a lubricant a ditive on macro-meso scale remains relativ ly unexplored. In particular, the lit rature is lacking about specific applications of graphene added lubricants on mechanical systems. this pape , t effec graphene added to a standard lubricants t cre te high performan e compounds has been investigated. Firstly, the Coeffici nt of Friction (CoF) of diffe ent compo i ions of lubricant-graphene compounds has been experimentally evaluated. In parti ular, a commercial grease and two com ercial oils have bee chosen to be used as base lu ricants. Results in terms of Coefficient of Friction values of all co pounds have been compar d each oth r. Final y, characterization resul s of graphene added grease have been relat d to that available from previous studies performed on a mechanical ompone t (a spline coupli g), commonly used in any industrial applic tions, lubricated by the same graphene grease compounds. R sults show that graphene added to viscous lubricants generally reduces the coefficient of friction, in both materials and components. © 2018 The Authors. Published by Elsevier B.V. This is an open access rt cle u der the CC BY-NC-ND license (http://cre tivecommons.org/licenses/by-nc-nd/3.0/) Peer-review u der responsibility of t Scie tific Committe o AIAS 2018 Internati al Conference on Stress Analysis. Abstract

© 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: Lubricants; graphene; friction; wear. Keywords: Lubricants; g aphene; friction; wear.

Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation. 1. Intro uction

1. Introduction

Tribological behaviour plays a primary role in the performance of mechanical systems, as friction and wear are the two major causes for energy and material losses. Tribological behaviour plays a primary role in the performance of mechanical systems, as friction and wear are the two major causes for energy and material losses.

2452-3216© 2018 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/3.0/) Peer-revi w u er responsibility of the Scientific Committee of AIAS 2018 International Conference on Stress Analysis. 2452-3216© 2018 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/3.0/) Peer-review u der re ponsibility of Scientific ommitt e of AIAS 2018 Internati al Conference on Stress Analysis.

* 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 PCF 2016. 2452-3216  2018 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/3.0/) Peer-review under responsibility of the Scientific Committee of AIAS 2018 International Conference on Stress Analysis. 10.1016/j.prostr.2018.11.107