PSI - Issue 7

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com Sci ceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structu al Integrity 7 (2017) 476–483 Structural Integrity Procedia 00 (2017) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2017) 000–000 ScienceDirect

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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. Copyright © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of the 3rd International Symposium on Fatigue Design and Material Defects. 3rd International Symposium on Fatigue Design and Material Defects, FDMD 2017, 19-22 September 2017, Lecco, Italy Investigation of crack propagation path in tube gears Francesca Curà a ,Andrea Mura a *, Carlo Rosso a a Politecnico di Torino, C.so Duca degli Abruzzi 24, Torino – 10129, Italy Abstract In this paper, the crack propagation behaviou in tube gears has been investigated. This kind of gear find application in aerospace and in particular in helicopter drivelines. For this reason, an accurate design against catastrophic failure due to particular crack propagation paths, has to be performed. In this work, the effect of tube length and rim thickness and also speed on crack propagation path has been analysed by means of extended finite elements models. In particular, to better understand the effect of speed, the changes in stress intensity factors K I and K II have been considered. Particular crack propagation shapes (wave propagation) have bee f und in some cases where the length ratio is particularly high. © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of the 3rd International Symposium on Fatigue Design and Material Defects. Keywords: fracture mechanics; crack path; crack propagation; gears; XFEM. 1. Introduction Lightweight gears are used in applications where weight reduction is a key f ctor, such as in aerospace industry. They are characterized by quite thin geometries and are realised in different shapes, according to the application requirements. These kinds of gear is geometrically characterized by thin rim thickness, Lewicki et al. (1997), and, if it is present, by a thin web thickness, Curà et al. (2015). Considering planetary gearboxes, in particular for helicopter applications, the solution to reduce weight consist in realizing satellites whose internal diameter is used as internal bearing race, Curà et al. (2016), and the sun as a part of the shaft. In this work, we focus on sun gear. 3rd International Symposium on Fatigue Design and Material Defects, FDMD 2017, 19-22 September 2017, Lecco, Italy Inv stigation of crack propagation path in tube gears Francesca Curà a ,Andrea Mura a *, Carlo Rosso a a Politecnico di Torino, C.so Duca degli Abruzzi 24, Torino – 10129, Italy Abstract In this paper, the crack propagation behaviour in tube gears has been investigated. This kind of gear find application in aerosp e and in particular in helicopter drivelines. For this reason, an accurate design against catastrophic failure due to particular crack propagation p ths, has to be performed. In this work, the effect of tube length and rim thi kness and also speed on cr ck r ti path has been analysed by means of extend d finite elements mod l . In particular to better understand the effect f speed, the changes in stress intensity factors K I and K II have been considered. Particular crack propagation shapes (wave propagation) have been found in some cas s where the length ratio is particularly high. © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of the 3rd International Symposium on Fatigue Design and Material D fects. Keywords: fracture mechanics; crack path; crack propagation; gears; XFEM. 1. Introduction Lightweight gears are used in applications where weight reduction is a key factor, such as in aerospac industry. They are characterized by quite thin geometries and are realised in different shapes, according to the application requirements. These kinds of gear is geometrically characterized by thin rim thickness, Lewicki et al. (1997), and, if it is present, by a thin web thickness, Curà et al. (2015). Considering planetary gearboxes, in particular for helicopter applications, the solution to reduce weight consist in realizing satellites whose internal diameter is used as internal bearing race, Curà et al. (2016), and the sun as a part of the shaft. In this work, we focus on sun gear. © 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.: +39-011-090-5907; fax: +39-011-090-6999. E-mail address: andrea.mura@polito.it

2452-3216 © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of the 3rd International Symposium on Fatigue Design and Material Defects. 2452-3216 © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of the 3rd International Symposium on Fatigue Design and Material Defects. * Corresponding author. Tel.: +39-011-090-5907; fax: +39-011-090-6999. E-mail address: andrea.mura@polito.it

* 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 Copyright  2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of the 3rd International Symposium on Fatigue Design and Material Defects. 10.1016/j.prostr.2017.11.115