PSI- Issue 9

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at www.sciencedire t.com ScienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 P o edia Structural Int gr ty 9 8 9–15 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. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. IGF Workshop “Fracture and Structural Integrity” Pearlitic Ductile Cast Iron: mechanical properties gradient analysis in graphite elements Francesco Iacoviello a *, Vittorio Di Cocco a , Gregory Favaro b a Università di Cassino e del Lazio Meridionale, DICEM, via G. Di Biasio 43, 03043, Cassino (FR), Italy b Anton Paar TriTec SA, Rue de la Gare 4, CH-2034, Peseux, Switzerland Abstract Ductile Cast Irons (DCIs) are able to combine a good versatility and high performances with a low cost, especially if compared to steels with analogous performances. For these reasons, although these grades have been relatively recently developed, DCIs applications are more frequent. Analyzing the damaging micromechanisms in static, quasi-static or cyclic conditions, the analysis of the role played by the graphite elements is not univocal. Sometimes, they are considered as voids embedded in a more or less ductile matrix, sometimes they are considered as a soft but homogeneous material. In this work, the role played by the graphite nodules in pearlitic grains is reviewed and their mechanical properties are investigated by means of nanohardness tests. © 2018 The Authors. Publishe by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. Keywords: Ductile cast irons; Graphite elmements; Damaging micromechanisms; Nanoindentation tests. 1. Introduction Relatively recently developed an optimized (Labrecque and Gagne, (1998) nd Rundman and Iacoviello (2016)), Ductile Cast Irons (DCIs) offer an interesting combination of good mechanical properties (similar to or even better than carbon steels) and good castability (peculiar of cast irons) controlling the graphite nodules shape (nodular and not lamellar) by means of nodularizing elements like Mg and not by means of long heat treatments (as in malleable cast irons) with a consequent strong reduction of costs. IGF Workshop “Fracture and Structural Integrity” Pearlitic Ductile Cast Iron: mechanical properties gradient analysis in graphite elements Francesco Iacoviello a *, Vittorio Di Cocco a , Gregory Favaro b a Università di Cassino e del Lazio Meridional , DICEM, via G. Di Biasio 43, 03043, Cassino (FR), Italy b Anton Paar TriTec SA, Rue de la Gare 4, CH-2034, Peseux, Switzerland Abstract Du tile Cast Irons (DCIs) are able to combin a good vers tility and igh performances with a low cost, specially if compared to steels with analog us performances. For t se re sons, alth ugh these grades have been relatively recently developed, DCIs applications are more fr quent. Analyzing the damaging micr chanisms in static, quasi-st tic r cyclic conditions, the analysis of the role played by the graphite elements is not univocal. S etimes, they are considered as voids embedded in a more or less ductil ma rix, sometimes they are consi ered as a soft but h mogeneous material. In this work, the r le played by the graphite nodules in pearlitic grains is reviewed and their mechanical properties are investigated by means of nanohardness tests. © 2018 The Aut ors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. Keywords: Ductile cast irons; Graphite elmements; Damaging micromechanisms; Nanoinde tation tests. 1. Introduction Relatively recently developed and optimized (Labrecque and Gagne, (1998) and Rundman and Iacoviello (2016)), Ductile Cast Irons (DCIs) offer an interesting combination of good mechanical properties (similar to or even better than carbon steels) and good castability (peculiar of cast irons) controlling the graphite nodules shape (nodular and not lamellar) by means of nodularizing elements like Mg and not by means of long heat treatments (as in malleable cast irons) with a consequent strong reduction of costs. © 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.

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 Gruppo Italiano Frattura (IGF) ExCo. 10.1016/j.prostr.2018.06.004 * Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452 3216 © 2018 Th Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. 2452-3216 © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. * Correspon ing auth r. Tel.: +39.07722993681; fax: +39.07762993781. E-mail address: iacoviello@unicas.it * Corresponding author. Tel.: +39.07722993681; fax: +39.07762993781. E-mail address: iacoviello@unicas.it