PSI - Issue 12

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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 A Mixed Numerical Approach to Evaluate the Dynamic Behavior of Long Trains N. Bosso a , A. Gugliotta a , N. Zampieri a * a Department of Mechanical and Aerospace Engineering, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino, Italy Abstract The evaluation of the longitudinal forces exchanged between the wagons composing a long train is very complex due to the large number of d.o.fs to be considered and due to the non linearities introduced by the coupling elements. The most common approach to simulate long trains is the use of simplified wagon models realized considering only the longitudinal d.o.f. In this way the number of d.o.fs used for the full vehicle model is equal or a little greater than the number of the connected cars. The efficiency of this approach, in calculating the in train forces during traction and braking operations, has been demonstrated by several authors in the literature. In particular the long train simulators have been developed with the aim to evaluate the longitudinal forces during the braking operations in order to optimize the braking strategy and the mass distribution along the train. This method is efficient to optimize the train configuration in order to minimize the in train forces, but it does not allow to evaluate the vehicle safety indexes (such as derailment, wheel unload and lateral force) because the wheel-rail contact forces are completely neglected. This work shows a novel approach where the long train numerical model, realized using the Simpack multibody code, is developed considering both simplified wagon models, with few d.o.fs and no contact module, and detailed wagon models, which include several d.o.fs and the algorithm for the contact forces evaluation. In particular this mixed technique allows to evaluate both the longitudinal train dynamic and the behavior of some of the wagons when the train is running on curve. The position of the detailed wagon models along the train combination can be selected by the user in order to evaluate the influence of a particular wagon position on the vehicle safety. © 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 A Mixed Numerical Approach to Evaluate the Dynamic Behavior of Long Trains N. Bosso a , A. Gugliotta a , N. Zampieri a * a Department of Mechanical and Aerospace Engineering, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino, Italy Abstract The evaluation of the longitudinal forces exchanged between the wagons composing a long train is very complex due to the large number of d. .fs to be considered and due to the non linearities introduced by the coupling elements. The most common approach to simulate l ng trains is the use of simplified wago mod ls realized considering only th lo gitudinal d.o.f. In this way the number of d. .fs used for t full vehicle model is equal or a little gr ater than the number of the connecte cars. The efficiency of this approach, in calculating th in train forces d ring trac ion and braking operations, has bee demonstrated by several authors in the literature. In particular the long train simula ors have been developed with the aim to evaluate th longitudin forces during the braking o erations in order to optimize the br king strategy and the mass distribution along the train. This method is efficient to optimiz the train c nfiguration in order to minimize th in train forces, but it does not llow o evaluate t e vehicle safety indexes (such as d railment, wheel u load and lateral forc ) because the wheel-ra l c ntact forces are compl tely neglected. This work shows a novel approach where the long train numerical model, realized using the Simpack multibody code, is d veloped considering both simplified wagon mod ls, with few d.o.fs nd no cont ct module, and detailed wagon models which inclu e several d.o.fs and the algorithm for th contact forces evaluation. In particular this mix d technique allows to evaluate both th longitudinal train dynamic and the behavior o some of the wago s when the train s running on curve. The position of e detailed wagon models along the train combination can be sel cted by the user in order to evaluate the influenc of a particular wagon position on th vehicle safety. © 2018 The Authors. Published by Elsevi r B.V. This is an o n access rticle und r the CC BY-NC-ND license (http://cre tivecommons.org/licenses/by-nc-nd/3.0/) Peer-review under responsibility of the Scie tific ommitte o AIAS 2018 Internati al Conference on Stress Analysis.

© 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: long train simulation; longitudinal dynamics; mixed numerical simulation; multibody; wheel-rail interaction Keywords: long train simulation; longitudinal dynamics; mixed numerical simulation; multibody; wheel-rail interaction

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

* Corresponding author. Tel.: +39-0110906997; fax: +39-0110906999 E-mail address: nicolo.zampieri@polito.it * Corresponding author. Tel.: +39-0110906997; fax: +39-0110906999 E-mail ad ress: nic lo.zampieri@polito.it

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.2018.11.083