PSI - Issue 13

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com cienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structu al Integrity 13 (2018) 273–278 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Int grity Procedia 00 (2018) 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. © 2018 The Auth rs. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 or anizers. ECF22 - Loading and Environmental effects on Structural Integrity Surface modification methods for fatigue properties improvement of laser-beam-welded Ti-6Al-4V butt joints Fedor Fomin 1 0F0F *, Benjamin Klusemann 1,2 , Nikolai Kashaev 1 1 Helmholtz-Zentrum Geesthacht, Institute of Materials Research, Materials Mechanics, Max-Planck-Straße 1, 21052 Geesthacht, Germany 2 Leuphana University Lueneburg, Institute of Product and Process Innovation, 21337 Lueneburg, Germany Abstract Surface and internal defects formed upon laser beam welding (LBW) have been recognized as a serious problem because they cause stress concentration leading to premature failure of a welded component. This paper seeks to remedy these weld imperfections by applying various post-weld treatments and analyzing their effec on the high cycle fatigue (HCF) performance of welded joints. High efficiency of laser-based post-processing techniques after welding such as laser surface remelting (LSR) and laser shock peening (LSP) was demonstrated and compared with conventional approaches. The study reveals that welding porosity determines the internal crack initiation of the surface-treated weldments. Influence of process parameters on porosity level and the HCF properties is presented in detail. Based on an extensive experimental study, practical guidelines needed to mitigate the notch effect from defects and to maximize the fatigue performance of the laser-welded Ti-6Al-4V butt joints are given. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: Laser beam welding; defects; porosity; high cycle fatigue; laser shock peening. 1. Introduction Laser beam welding (LBW) has received significant attention over the last decades due to high efficiency and superior technical characteris ics compared to c nventional fusion welding methods. Implementation of the LBW process into manufacturing chain offers important economic benefits (Duley, 1998). However, it has been found that these benefits are compensated by poor fatigue and damage tolerance behaviour of the joints, which primarily stems ECF22 - Loading and Environmental effects on Structural Integrity Surface modification methods for fatigue properties improvement of laser-beam-welded Ti-6Al-4V butt joints Fedor Fomin 1 0F0F *, Benjamin Klusemann 1,2 , Nikolai Kashaev 1 1 Helmholtz-Zentrum Geesthacht, Institute of Materials Research, Materials Mechanics, Max-Planck-Straße 1, 21052 Geesthacht, Germany 2 Leuphana University Lu neburg, Institute of Produc and Process Innovation, 21337 Lueneburg, Germany Abstract Surface and internal defects formed upon laser beam welding (LBW) have been recognized as a serious problem because they cause stress conce tration leading to premature failure of a welded component. This paper seeks to remedy these weld imperfections by applying various pos -wel treatments and analyzing their ffect on the high cycle fatigu (HCF) p rformance of welded jo nts. High efficiency of laser-based post-processing techniques after welding suc as laser surface remelting (LSR) and laser shock peening (LSP) was demonstrated and c mpared wit conventional approaches. The study reveals that welding porosity determines the internal crack initiation of the surface-treated weldments. Influence of proc ss parameters on porosity level an the HCF properties is presented in detail. Based on an extensiv exp rimental study, practi al guidelines needed to mitigate the notch effect from defects and to maximize the fatigue performanc of the laser-welded Ti-6Al-4V butt joints are given. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: Laser beam welding; defects; porosity; high cycle fatigue; laser shock peening. 1. Introduction Laser beam welding (LBW) has received significant attention over the last decades due to high efficiency and superior technical characteristics compared to conventional fusion welding methods. Implementation of the LBW process into manufacturing chain offers important economic benefits (Duley, 1998). However, it has been found that these benefits are compe sated by poor fatigue and damage tolerance behaviour of the joints, which primarily stems © 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.: +49(4152)87-2529; fax: +49(4152)87-42536. E-mail address: fedor.fomin@hzg.de * Corresponding author. Tel.: +49(4152)87-2529; fax: +49(4152)87-42536. E-mail ad ress: fed fomin@hzg.de

* Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452-3216 © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. 2452-3216 © 2018 The Authors. Published by Elsevier B.V. Peer review under r sponsibility of the ECF22 organizers.

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. Peer-review under responsibility of the ECF22 organizers. 10.1016/j.prostr.2018.12.046