PSI - Issue 13

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com Sci ceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structu al Integrity 13 (2018) 71 –715 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. ECF22 - Loading and Environmental effects on Structural Integrity Strain Rate Sensitivity of Microstructural Damage Evolution in a Dual-Phase Steel Pre-Charged with Hydrogen Tsubasa Kumamoto a *, Motomichi Koyama a , Kaneaki Tsuzaki a, a Department of Mechanical Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan b Hydrogenious, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan We evaluated the strain rate sensitivity of the micro-damage evolution behavior in a ferrite/martensite dual-phase steel. The micro damage evolution behavior can be divided into three regimes: damage incubation, damage arrest, and damage growth. All regimes are associated with local deformability. Thus, the total elongation of DP steels is determined by a combination of plastic damage initiation resistance and damage growth arrestability. This fact implies that hydrogen must have a critical effect on the damage evolution, because hydrogen enhances strain localization and lowers crack resistance. In this context, the strain rate must be an important factor because it affects the time for microstructural hydrogen diffusion/segregation at a specific microstructural location or at the damage tip. In this study, tensile tests were carried out on a DP steel with different strain rates of 10 − 2 and 10 − 4 s − 1 . We perfo med t e damage quantification, microstructure characterization and fractography. Specifically, the quantitative data of the damage evolution was analyzed usi g the classification of the damage evolution regimes in order to separatel elucidate the ffects of the hydrogen on damage initiation resistance and damage arrestability. In this study, we obtained the following conclusions with respect to the strain rate. Lowering the strain rate increased the damage nucleation rate at martensite and reduced the critical strain for fracture through shortening the damage arrest regime. However, the failure occurred via ductile modes, regardless of strain rate. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: Hydrogen embrittlement; Dual-phase steel; Quantitative damage analysis © 2018 The Authors. Published by Els vi r B.V. Peer-review under responsibil ty of the ECF22 organizer . ECF22 - Loading and Environmental effects on Structural Integrity Strain Rate Sensitivity of Microstructural Damage Evolution in a Dual-Phase Steel Pre-Charged with Hydrogen Tsubasa Kumamoto a *, Motomichi Koyama a , Kaneaki Tsuzaki a,b a Department of Mechanical Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan b Hydroge ous, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan Abstract We evaluated the strain rate sensitivity of the micro-damage evolution behavior in a ferrite/martensite dual-phase steel. The micro damage evolution behavior can be divided into three regim s: damage incubation, damag arrest, and amage growth. All regimes are associated with local deformability. Thus, the total elongation of DP steels is etermined by combination of plastic damage initi ti n resistance and amage growth arrestability. This f ct implies that hydrogen ust have a critical effect on the evoluti , because hydrogen enhances strain localization and lowers crack resistance. In this context, the strain rate must be an importa t factor b cause it aff cts the time for microstructural hydrogen diffusion/segr gation at a sp cific mic ostructural locatio or at the damage tip. In this study, t nsil tests were carried out on a DP steel with different str in rates of 10 − 2 and 10 − 4 s − 1 . We performed the damage quantification, microstructure characterization and fractography. Specifically, the quantit tive data of th damage evolution was analyzed using the la sification of the damage evolution regimes in order to separately elucidate the ef ects of the hydr gen on damage initiatio resistance and damage arrestability. In this study, we obtained the following onclusions with respect to the strain rate. Lowering the trai rate increased the damage nucleation rate at marte site and reduced the ritical strain for fracture through shortening the damage ar est regime. However, th failure occurred via ductile modes, regar less of str in rate. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: Hydrogen embrittlement; Dual-phase steel; Quantitative damage analysis Abstract

© 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.:+81-92-802-3288. E-mail address: 2TE17831S@s.kyushu-u.ac.jp * Corresponding author. Tel.:+81-92-802-3288. E-mail ad ress: 2TE17831S@s.kyushu u.ac.jp

* 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 o ganizers.

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.2018.12.118