PSI - Issue 8

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 P o edi Structural Integr ty 8 (2018) 14–23 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2017) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2017) 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. Copyright © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of AIAS 2017 International Conference on Stress Analysis AIAS 2017 International Conference on Stress Analysis, AIAS 2017, 6-9 September 2017, Pisa, Italy Austempered Ductile Iron (ADI) for gears: Contact and bending fatigue behavior Franco Concli a * a Free University of Bolzano/Bozen, piazza Università 1, Bolzano 39100, Italy Abstract Austempered Duc il Ir n (ADI) represents an alternative solution f r the manufactur ng of the housing of small planetary gearboxes, with the gear teeth obtained directly on the housing itself: such solution combines a cost-effective process with the possibility of obtaining complex geometry of the case. With respect to most traditional solutions, by means of ADI the requirements of strength and accuracy of the gear teeth can be satisfied without an additional finishing step after the heat treatment: the teeth can be obtained by broaching and, thanks to the low distortion which can be granted by the austempering process, a subsequent finishing operation is not needed. For these reasons, ADI has been selected for the application to a family of small gearboxes for automation. Due to the limited experience and data available for such material, to improve the design and rating processes, a testing campaign has been performed. The ai was to obtain strength data f r bending and contact fatigue, considering the specific manufacturing and h at treatment proces es. The paper describes the test procedures adopted and the test results, which have been obtained on gears specimens by means of Singl Tooth Fatig e (STF) and pitting tes s on a FZG type bench respectively. Th tests are supporte by metallurgical investigations on the failed teeth, to describe and understand the failure mechanisms. The results are th n compared with the data and the shape curves provided by th intern tional standa ds. © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of AIAS 2017 International Conference on Stress Analysis. Keywords: Austempered ductile iron; gears; bending; pitting; fatigue; tests AIAS 2017 International Conference on Stress Analysis, AIAS 2017, 6-9 September 2017, Pisa, Italy Austemp red Du tile Iron (ADI) for gears: Contact and bending fatigue behavior Franco Concli a * a Free University of Bolzano/Bozen, piazza Università 1, Bolzano 39100, Italy Abstract Austempered Ductile Iron (ADI) represents an alternative solution for t e manufa turing of the housing of small planetary gearboxes, with the gear teeth obtain d directly on the housing itself: such solution combi es a cost-effective process with the po sibility of obtaining c mpl x geom try of th c se. With respect to most tr ditional solutions, by means of ADI the requir ments of strength and accuracy of the gear teeth can be satisf ed ithout an additional finishing step after the h at treatment: the teeth can be obtai ed by broaching and, thanks t the low distortion whi h can be gr nted by the auste pering process, a sub equent finishing operation is not ne ded. For these re sons, ADI has been selected for the application to a f mily of small gearboxes for auto ation. Due to the limited experience and data availabl for such material, to improve the design and rating processes, a testing campaign has been p rformed. Th aim was to obtain st ength da a for ben ing an contact fa igu , con idering the specific manuf cturing and he t treatment proce ses. The paper describes the test procedur adopte and the t st r sults, which have been obtained on gears specimens by means f Single Tooth Fatigue (STF) and pitting t sts on a FZG type b nch respectiv ly. The tests are support by metallurgical inv stigations o the fa led teeth, to describe nd understan th failure mechanisms. The r sults are hen compare with th data and the shape curves provided by the intern tional standards. © 2017 The Autho s. Published by Elsevier B.V. Peer-review und r responsibility of the Scientific Committee of AIAS 2017 International Conference on Stress Analysis.

© 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: Austempered ductile iron; gears; bending; pitting; fatigue; tests

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

* Corresponding author. Tel.: +39-0471-017748; fax: +39-0471-017009. E-mail address: franco.concli@unibz.it * Correspon ing author. Tel.: +39-0471-017748; fax: +39-0471-017009. E-mail address: franco.concli@unibz.it

2452-3216 © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of AIAS 2017 International Conference on Stress Analysis. 2452 3216 © 2017 Th Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of AIAS 2017 International 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 Copyright  2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of AIAS 2017 International Conference on Stress Analysis 10.1016/j.prostr.2017.12.003