PSI - Issue 13

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 13 (2018) 222–225 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 Subcritical crack growth in sandstone in aqueous environment with different calcium ion concentration Yoshitaka Nara a, *, Hiroyuki Takeda a a Kyoto University, Kyoto-Daigaku-Katsura, Nishikyo-ku, Kyoto 615-8540, Japan Investigating the time-dependent fracturing in sandstone is crucial to consider the long-term integrity of a sedimentary rock mass surrounding structures. Subcritical crack growth is one of the main causes of the time-dependent fracturing in rock materials. For the long-term integrity, it is essential to investigate subcritical crack growth in rock, which is influenced by the surrounding environmental conditions. Numerous cementitious materials are used to construct various structures such as underground repositories for radioactive waste, underground power plants, etc. In these cases, the calcium ion concentration in the ground water in a rock mass surrounding these structures is high. Therefore, investigation on the subcritical crack growth in rock in water with a high cal ium ion concentration is essential. In this study, subcritical crack growth in sandstone is measured in distilled water and calcium hydroxide solution (Ca(OH) 2 ) to investigate the influence of calcium ions on the time-dependent fracturing in rock. Berea sandstone was used as a rock sample. The load-relaxation method of the double-torsio test was used to measure the crack velocity and the stress intensity factor. All measurements have been carried out under controlled temperature and relative humidity. It was shown that the crack velocity in a calcium hydroxide solution is lower than that in distilled water even though the pH was high. In previous researches, it has been considered that the crack velocity in rock increased when the pH was high from the measurements in water and sodium hydroxide solution (NaOH). Therefore, it is considered that calcium ion affects the decrease of the crack velocity. It is concluded that a water environment with a high calcium ion concentration is suitable for the long-term integrity of a sedimentary rock mass. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. ECF22 - Loading and Environmental effects on Structural Integrity Subcritical crack growth in sandstone in aqueous environment with different calcium ion concentration Yoshitaka Nara a, *, Hiroyuki Takeda a a Kyoto University, Kyoto-Daigaku-Katsura, Nishikyo-ku, Kyoto 615-8540, Japan Abstract Investigating the time-dependent fracturing in sandstone is crucial to consider the long-term integrity of a sedimentary rock mass surrounding structur s. Subcritical crack growth is one of the main causes of the time-dependent fracturing in rock materials. For the long-term integrity, it is essential to investigate subcritical crack growth in rock, which is infl e ced by the sur ounding environmental conditions. Numerous cementitious materials are used to construct various structures such as underground repositori s for radioactive waste, undergrou d p wer plants, etc. In these cases, the calcium ion concentration in the ground water in a rock mass surrounding thes structures is high. Therefore, investigation on t subcritical crack growth in rock in water with a high alcium ion co ce tration i essential. In this study, subcritical crack growth in sandstone is measured i distilled water and calcium hydroxide s lution (Ca(OH) 2 ) to investigate the infl ence of calcium i ns o the time-dependent fracturing in rock. Berea s ndstone was used as a r ck s mple. The load-rel xation method of the double-torsion t st was us d to measure the crack velocity and the stress int nsity factor. All measurements have been carried out under controlled temperature and relative humidity. It was shown that the crack velo ity in a calcium hydroxide solution is lower than that in distilled water even though the pH was high. In previous resear hes, it has bee considered that the crack velocity in rock increased when the pH was high from the measurements in water and sodium hydroxide solution (NaOH). Therefore, it is considered that calcium ion affects t e decrease of th crack velocity. It is concluded that a water environment with a high calcium ion concentration is suitable for the long-t rm integrity of a sedimentary rock mass. © 2018 The Authors. Published by Elsevier B.V. Peer-review under esponsibility of the ECF22 organizers. Abstract

© 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: Subcritical crack growth; Double-torsion method; Sandstone; Water; Calcium ion Keywords: Subcritical crack growth; Double-torsion method; Sandstone; Water; Calcium ion

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 © 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. * Corresponding author. Tel.: +81-75-383-3210; fax: +81-75-874-1418. E-mail address: nara.yoshitaka.2n@kyoto-u.ac.jp * Corresponding author. Tel.: +81-75-383-3210; fax: +81-75-874-1418. E-mail ad ress: nara.yoshitaka.2n@kyoto-u.ac.jp

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.2018.12.037