PSI - Issue 2_B

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com ienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Struc ural Integrity 2 (2016) 3569–3576 Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2016) 000–000 Available online at www.sciencedirect.com 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. 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. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Mechanical behavior and fracture mechanisms of titanium alloy welded joints made by pulsed laser beam welding Benjamin Sarre a,1 , Sylvain Flouriot a , Guillaume Geandier c , Benoi Pan caud b , Victor de Rancourt a a CEA Valduc, Is-Sur-Tille, 21120, France b LASMIS, Universite´ de Technologie de Troyes, 10010, Troyes, France c Institut Jean Lamour, CNRS - Universite´ de Lorraine, 54000, Nancy, France Abstract Component parts made of a commercial two-phase α + β Ti-6Al-4V alloy can be assembled by Nd:YAG pulsed laser beam welding. Welding processes are known to result in strong heterogeneities, i.e. strength mismatch and residual stresses and are also accompanied by a great variety of flaws, which is why the failure behavior of welded joints is still di ffi cult to predict. The present work aims at gaining insights into the mechanical behavior of Ti-6Al-4V welds and also investigates the e ff ect of defects such as the welding joint / weld root misalignment and pore size distribution. Comprehensive metallurgical analyses in the weld region are first carried on on the basis of optical, X-ray di ff raction and SEM analyses. Then, the overmatch is highlighted from hardness measurements of a weld cross section. Next, tensile testing of both the base metal and fusion zone are performed. The tensile specimens are taken along and parallel to a partial penetration weld and also in the base metal. Two di ff erent thicknesses are chosen for weld embedding specimens, respectively 1.5mm and 2.5mm. The latter one embeds the notch coming from the partial penetration. Tensile tests displayed a slight overmatch, which e ff ect is underlined by digital image correlation on transversal 1.5mm tensile specimens. Neverthel s , high-speed camera data acquisition revealed that such a slight overmatch was not su ffi cient to prevent the occurrence of plasticity within the weld in the case of the 2.5mm tensile specimens. It also highlighted the influence of plasticity on the crack path, which tends to bifurcate from the ard st to the oftest area. Further aspects of the weld structure and mechanical behavior heterogeneities are finally discussed. © 2016 The Authors. Published by Elsevier B.V. r ie under responsibility of the Scientific Committee of ECF21. Keywords: Ti-6Al-4V, Laser Beam Welding, mechanical behavior, failure; 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy echanical behavior and fracture echanis s of titaniu alloy welded joints made by pulsed laser bea elding Benjamin Sarre a,1 , Sylvain Flouriot a , Guillau e Geandier c , Benoit Panicaud b , Victor de Rancourt a a CEA Valduc, Is-Sur-Tille, 21120, France b LASMIS, Universite´ de Technologie de Troyes, 10010, Troyes, France c Institut Jean Lamour, CNRS - Universite´ de Lorraine, 54000, Nancy, France Abstract Component parts made f a ommercial two-phase α + β Ti-6Al-4V alloy can be assembled by Nd:YAG pulsed laser beam welding. Welding processes are known to result in strong heter geneities, i.e. strength mismatch and residual stresses and are also accompanied by a great variety of flaws, which is why the failure behavior of welded joints is still di ffi cult to predict. The present work aims at gaining insights into the mechanical behavior of Ti-6Al-4V welds and also investigates the e ff ect of defects such as the welding joint / weld root misalignment and pore size distribution. Comprehensive metallurgical analyses in the weld region are first carried on on the basis of optical, X-ray di ff raction and SEM analyses. Then, the overmatch is highlighted from hardness measurements of a weld cross section. Next, tensile testing of both the base metal and fusion zone are performed. The tensile specimens are taken along and parallel to a partial penetration weld and also in the base metal. Two di ff erent thicknesses are chosen for weld embedding specimens, respectively 1.5mm and 2.5mm. The latter one embeds the notch coming from the partial penetration. Tensile tests displayed a slight overmatch, which e ff ect is underlined by digital image correlation on transversal 1.5mm tensile specimens. Nevertheless, high-speed camera data acquisition revealed that such a slight overmatch was not su ffi cient to prevent the occurrence of plasticity within the weld in the case of the 2.5mm tensile specimens. It also highlighted the influence of plasticity on the crack path, which tends to bifurcate from the hardest to the softest area. Further aspects of the weld structure and mechanical behavior heterogeneities are finally discussed. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: Ti-6Al-4V, Laser Beam Welding, mechanical behavior, failure; © 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.: + 33 80 23 00 00. E-mail address: benjamin.sarre@cea.fr ∗ Corresponding author. Tel.: + 33 80 23 00 00. E-mail address: benjamin.sarre@cea.fr

* 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. 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.2016.06.445 2452-3216 © 2016 The uthors. P blished by Elsevier B.V. Peer-review und r responsibility of the Scientifi Committee of ECF21. 2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21.