PSI - Issue 7

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 7 (2017) 415–422 Structural Integrity Procedia 00 (2017) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2017) 000–000 ScienceDirect

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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. Copyright © 2017 The Authors. ublished by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of the 3rd International Symposium on Fatigue Design and Material Defects. 3rd International Symposium on Fatigue Design and Material Defects, FDMD 2017, 19-22 September 2017, Lecco, Italy Influence of Porosity on the High Cycle Fatigue Behaviour of Laser Beam Welded Ti-6Al-4V Butt Joints F. Fomin*, N. Kashaev Institute of Materials Research, Materials Mechanics, Helmholtz-Zentrum Geesthacht, Max-Planck-Str. 1, 21502 Geesthacht, Germany Abstract Surface defects and internal discontinuities are inevitable results of the laser beam welding (LBW) process regardless of the material used. Comprehensive understanding of the fatigue degradation caused by these defects is of major concern for the introduction of LBW into manufacturing or repair processes. The present paper focuses on the effect of inherent welding-induced material flaws on the high cycle fatigue behaviour of the laser welded Ti-6Al-4V butt joints. If the surface quality of the welded joint is sufficiently high, the transition of the crack origin from the surface to the subsurface occurs. The mechanisms of internal fatigue crack formation and growth at the early stages were studied. A typical fish-eye pattern of fracture surface was observed in close proximity to the crack origin. The model based on fracture mechanics for durability prediction in the presence of randomly distributed porosity was developed. The link between theory, modelling and experiment was successfully demonstrated. © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of the 3rd International Symposium on Fatigue Design and Material Defects. Keywords: Porosity; laser beam welding; high cycle fatigue; physically short cracks; analytical model. 1. Introduction Due to high productivity and flexibility, laser beam welding (LBW) of titanium alloys provides significant practical advantages over conventional j ining t chniques. In addition, local hardening of the welding seam yields quite impressive results in the tensile tests, namely, the fracture of the weldment in the base material (BM) (Kashaev et al., 3rd International Symposium on Fatigue Design and Material Defects, FDMD 2017, 19-22 September 2017, Lecco, Italy Influence o Porosity on the High Cycle Fatigue Behaviour of Laser Beam Welded Ti-6Al-4V Butt Joints F. Fomin*, N. Kashaev Institute of Materials Research, Materials Mechanics, Helmholtz-Zentrum Geesthacht, Max-Planck-Str. 1, 21502 Geesthacht, Germany Abstract Surface defects and internal discontinuities are inevitable results of th laser b am welding (LBW) process regardless of the material used. Comprehensive understanding of the fatigue degradation caused by thes defects is of major concern for the introduction of LBW into manufacturing or repair processes. The present paper focuses on t effect of in rent welding-induced material flaws on the high cycle fatigue behaviour of the laser weld d Ti-6Al-4V butt joints. If the surf ce quality of the welded joint is sufficiently high, the transiti n of the crack origin from t surface to the subsurfac occurs. The mechanisms of internal fatigue crack formation and growth at the early stage wer studied. A typical fish-ey pattern of fracture surface was ob erved in close proximity to the crack origin. The model based on f cture echanics for durability rediction in th presence of randomly distributed porosity was developed. The link b tween theory, modelling and experiment was successfully demonstrat d. © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of the 3rd International Symposium on Fatigue Design and Material Defects. Keywords: Porosity; laser beam welding; high cycle fatigue; physically short cracks; analytical model. 1. Introduction Due to high productivity and flexibility, laser beam welding (LBW) of titanium alloys provides significant practical advantages over conventional joining techniques. In addition, local hardening of the welding seam yields quite impressive results in the tensile tests, namely, the fracture of the weldment in the base material (BM) (Kashaev et al., © 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 872529; fax: +49 4152 8742536. E-mail address: fedor.fomin@hzg.de * Corresponding author. Tel.: +49 4152 872529; fax: +49 4152 8742536. E-mail address: fedor.fomin@hzg.de

2452-3216 © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of the 3rd International Symposium on Fatigue Design and Material Defects. 2452-3216 © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of the 3rd International Symposium on Fatigue Design and Material Defects.

* 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 Copyright  2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of the 3rd International Symposium on Fatigue Design and Material Defects. 10.1016/j.prostr.2017.11.107