PSI - Issue 1

ScienceDirect Procedia Structural Integrity 1 (2016) 118–125 Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com Sci ceDirect Structural Integ ity 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. XV Portuguese Conference on Fracture, PCF 2016, 10-12 February 2016, Paço de Arcos, Portugal Fatigue assessment of steel half-pipes bolted connections using local approaches F. Öztürk a , J.A.F.O. Correia b, *, C. Rebelo a , A.M.P. De Jesus b , L. Simões da Silva a a ISISE, Department of Civil Engineering, University of Coimbra, Rua Luís Reis Sa tos, Pólo II, 3030-788 Coimbra, Portugal b INEGI, Engineering Faculty, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal Abstract This paper proposes a multiaxial fatigue assessment of a steel half-pipe bolted connection using a local energy-based approach. This bolted connection has been proposed for onshore wind turbine towers. A global linear-elastic model with beam elements for the onshore wind turbine tower was developed taking into account the stiffness of the joint. Damage equivalent fatigue loads were applied in global beam model. To assess the stiffness of the joint a linear-elastic model considering the preload on the bolts was made. A local elastoplastic model was built to obtain the maximum principal stresses and strains. Using this analysis was possible to determine the SWT damage parameter and the number of cycles to failure for the steel half-pipes bolted connection under vestigati n. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: Elastoplastic analysis; Half-pipes bolted connections; Finite element modelling; Local approaches; Multiaxial fatigue. 1. Introduction Recently, a steel hybrid solution for onshore wind turbine towers using a lattice structure for the lower portion of the tower and a tubular upper portion was proposed. This solution targeted tall onshore applications supporting multi megawatt wind turbines. Previous developments focused on conceptual design and structural predesign of one case study based on equivalent load tables and using S355 steel grade: hub height 150 meters (40 meters lattice part, 110 h Copyright © 2015 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 PCF 2016. © 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.: +351225082151; fax: +351225081584. E-mail address: jacorreia@inegi.up.pt

* 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 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Copyright © 2015 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 PCF 2016. 10.1016/j.prostr.2016.02.017