PSI - Issue 2_A

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) 1457–1464 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2016) 000–000 Available online at www.sciencedirect.com 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 Fatig microstructu l evolution in pseudo elastic NiTi all y Vittorio Di Cocco a *, Francesco Iacoviello a , Stefano Natali b a DICeM – University of Cassino and Southern Lazio, Cassino (FR) 03043, Italy b D.I.C.M.A - “La Sapienza” University, Rome 0018, Italy Abstract Shape memory property characterizes the behavior of many Ti based alloys (SMAs). This property is due to a metallurgical phenomenon, which allows to change the lattice structure without boundaries changing as a reversible transition. Equiatomic NiTi alloys are among the most industrially used SMAs: they are charac erized by two different mechanical behaviors in terms of shape recovering:  a shape memory effect (SME). This is obtained when the recovery of the initial shape takes place only after heating over a critical temperature, with a consequent crystallographic structure transition;  a pseudoelastic effect (PE). This is obtained when the critical temperature is lower than environmental temperature. In this case, the recovery of the initial shape takes place only after unloading. In recent years, research relating to materials of shape memory has gone in the direction of application in many fields of engineering such as aerospace or mechanical systems. In this work the evolution of microstructural lattice has been studied taking in to account the effect of low cycles fatigue loads. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: NiTi alloy; Shape memory alloy; Ftigue 1. Introduction Shape memory alloys (SMAs) are an interesting class of materials characterized by the ability to recover the original shape also after high val es of deformation. The ability to recover the initial shape can be classified as two different ways: 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Fatigue microstructural evolution in pseudo elastic NiTi alloy Vittorio Di Cocco a *, Francesco Iacoviello a , Stefano Natali b a DICeM – University of Cassino and Southern Lazio, Cassino (FR) 03043, Italy b D.I.C.M.A - “La Sapie za” University, Rome 0018, Italy Abstract Shape memory property characterizes the behavior of many Ti based alloys (SMAs). This property is due to a metallurgical p enomenon, which allows to chang the lattice structure without oundaries changing as a reve sible transition. Equiatomic NiTi alloys are among the m st industrially used SMAs: they are c aracterized by two different m chanical behav ors in terms of shape rec vering:  a shape memory effect (SME). This is obtained when the recovery of the initial shape takes place only after heating over critical t peratur , with a consequent crystallograp ic structure transit on;  pseudoelastic effect (PE). This is obtained when the critical temperature is lower than environmental temperature. In thi case, the recov ry of the in tial shape takes place only after unloading. In recent years, research relating t materials of shape m mory has gone in the direction of application in many fields of engineering such as aerospac or mechan cal systems. In t is wo k the v lution of micro tructural lattice has been studied taking in to account the effect of low cycles fatigue loads. © 2016 The Authors. Published by Elsevier B.V. Peer-review under respons bility of the Scientific Committee of ECF21. Keywords: NiTi alloy; Shape memory alloy; Ftigue 1. Introduction Shap memory alloys (SMAs) are an interesting class of materials characterized by the ability to recover the original shape also after high values of deformat on. The ability to reco er the initial shape can be classified as two different ways: Copyright © 2016 The Auth rs. Published by Elsevier B.V. This is an open access articl u der 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. © 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 und r responsibility of the Scientific Committee of ECF21. 2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer review under r sponsibility of the Scientific Committee of ECF21. * Corresponding author. Tel.: +39.0776.2994334; fax: +39.0776.2993733 E-mail address: v.dicocco@unicas.it * Corresponding author. Tel.: +39.0776.2994334; fax: +39.0776.2993733 E-mail ad ress: v.dicocco@unicas.it

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.2016.06.185