PSI - Issue 12

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com ScienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structu al Integrity 12 (2018) 538–552 Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2018) 000–000

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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.2018.11.065 ∗ Correspon ing author. Tel.: + 39-(0)81-7682451; cell: + 39-347-6080985. E-mail address: penta@unina.it 2210-7843 c 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. Although over the last three decades most of the railway tracks have been built by the continuous welded rail technique, several technical problems still prevent the full achievement of the best performance of this constructive solution in terms of maintainability, energy consumption reduction, comfort degree o ff ered to the passengers and lifetime of the rails and rolling stock. Surely, a key role is played by the natural trend of this system toward the thermal buckling phenomenon and, even more so, the unpredictability of the thermal and mechanical conditions in which this phenomenon may occur. 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 Aut ors. P blished by Elsevi r B.V. This is an open access article under the CC BY-NC-ND lice se (http://creativecommons.org/licenses/by-nc-nd/3.0/) Peer-review under responsibilit of the Scientific Committee of AIAS 2018 International Conference on Stress Analysis. AIAS 2018 International Conference on Stress Analysis A continuous model for the railway track analysis in the lateral plane M. Catena a , A. Gesualdo b , S. Lisi a , F. Penta c, ∗ , G.P. Pucillo c a Technical Management / Technological and Experimental Standard - Superstructure, Rete Ferroviaria Italiana - RFI S.p.A., Piazza del a Croce Rossa 1, 00161, Rome, Italy b Department of Structures for Engineering and Architecture, University of Naples Federico II, via Claudio 21, 80125 Naples, Italy c Department of Industrial Enginee ing, University of Naples Feder co II, Piazzale Tecchio 80, 80125 Naples, Italy Abstract This paper deals with a mechanical model for the analysis of the railway track behaviour built by exploiting the periodicity of the track-structure. The starting point of this study is the analysis of the inner forces transferring modes. They have been determined by the unit principal vect rs analysis of the base cell transfer mat ix. The proposed model is able to reproduce accurately the track behaviour in transferring its inner forces. However, solutions that are equilibrated but not kinematically admissible are obtained from it when transversal loads are applied. In additions, only bound ary conditions compatibles with the track transferring modes can be satisfied. This inconsistency is eliminated by superposition of a corrective deformed shape. This is derived from the eigenvectors of the transfer matrix pertaining to self-equilibrated systems of bending moments decaying along the track. The application field of the proposed track model is also discussed and the results of a validation study carried out by F.E. analysis are finally presented. c 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. Keywords: Periodic beam-like structure; Homogenization; Transfer state matrix eigen-analysis; Continuous welded rail; Railway track model T © 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 1. Introduction