PSI - Issue 2_A

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 Struc ural Integrity 2 (2016) 309 –3097 Available online at www.sciencedirect.com ScienceDirect Structural Integrity 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. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Effect of compr ssive esidual stress generated by plastic preload on fatigue initiation of 6061 Al-alloy M. Benachour a, *, N. Benachour a, b , M. Benguediab c a Ingeniery of Mechanical Systems and Materials Laboratory, University of Tlemcen, 13000, Tlemcen,Algeria b Department of Physics, Faculty of Sciences, University of Tlemcen, 13000, Tlemcen,Algeria c Laboratory of Materials & Reactives Systems, Mechanical Engineering Departement, University of Sidi Bel Abbes, 22000, Algeria Abstract In this paper the effect of compressive residuals stresses generated by plastic preload on fatigue crack initiation and performed on 6061 Al-alloy finite plate with central hole was studied. Finite element analysis (FEA) was used to generate residual stress field. The effect of residual stress on the fatigue crack initiation was investigated for cyclic tension. Based on elasto-plastic analysis at notch, fatigue initiation lives were predicted using fatigue code. Results shown that the fatigue initiation lives were affected by the presence of c mpressive residual stress at otch and total residual field. Intuiti nally, stress ratio effect in presence of residual str s was hig light . © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of th Scientific Committee of ECF21. Keywords: fatigue crack initiation, compressive residual stress, stress r tio, 6061 Al-alloy ; 1. Introduction Failure due to fatigue accounts for nearly 90% of all mechanical failure (Dieter, 1986). Aluminum in its solid forms has good workability and high strength to weight ratio as an alloy. 6xxx series aluminum alloys were produced by mixing magnesium (Mg) and silicon (Si) to pure aluminum (Van Horn, 1967). Typical uses of the 6xxx seri s aluminum alloys are found in automotiv , aerospace, marine and structural applications (hydraulic pistons, electrical fittings and connectors…etc, (Archer and Jefferies, 1967). 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Effect of compressive residual stress generated by plastic preload on fatigue initiation of 6061 Al-alloy M. Benachour a, *, N. Benachour a, b , M. Benguediab c a Ingeniery of Mechanical Systems and Materials Laboratory, University of Tlemcen, 13000, Tlemcen,Algeria b Department of Ph ics, F culty of Sciences, University of Tlemcen, 13000, Tlemcen,Algeria c Laboratory of Materials & R actives Systems, Mechani al Engineering Departement, University of Sidi Bel Abbes, 22000, Algeria Abstract In this paper the effect of compressive residuals stresses generated by plastic preload on fatigue crack initiation and performed on 6061 Al-alloy finite plate with c ntral hole wa udied. Fi ite element nalysis (FEA) w s us d to ge er e residual stress field. The effect f residual str ss on the f tigue cr ck init ation was investigated for cyclic tension. Based o elasto-plastic analys s at notch, fatigue in tiation lives wer predicted using fatigue code. Results shown that th fatigue initiation lives were affected by the presence of compress residual stress at notch and total residual field. Intuitionally, stress ratio effect in presence o resi ual stress was highlight . © 2016 The Authors. Publish d by Elsevier B.V. Peer-review under espons bility of the Scientific Committee of ECF21. Keywords: fatigue crack initiation, compressive residual stress, stress ratio, 6061 Al-alloy ; 1. Introduction Failure due to fatigue accounts for nearly 90% of all mechanical failure (Dieter, 1986). Aluminum in its solid forms has good workability a d high strength to weight ratio as an alloy. 6xxx series aluminum alloy were produced by mixing m gnesium (Mg) and silicon (Si) to pure luminum (Van Horn, 1967). Typical ses of the 6xxx series aluminum alloys ar found in automotive, aerospace, marine and structu al applications (hydraulic pistons, electrical fittings nd conn ct rs…etc, (Archer and Jefferies, 1967). Copyright © 2016 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 ECF21. © 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 2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review und r responsibility of the Scientific Committee of ECF21. 2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer review under r sponsibility of the Scientific Committee of ECF21. * Corresponding author. Tel.: +213 772-640-929; fax: +213-43-285-685 E-mail address: bmf_12002@yahoo.fr * Corresponding author. Tel.: +213 772-640-929; fax: +213-43-285-685 E-mail ad ress: bmf_12002@yahoo.fr

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Copyright © 2016 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 ECF21. 10.1016/j.prostr.2016.06.386