PSI - Issue 2_A

Available online at www.sciencedirect.com

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com S ienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structu al Integrity 2 (2016) 525–532 ScienceDirect Structural Integrity Procedia 00 (2016) 000–000 Structural Integrity Procedia 00 (2016) 000–000 Available online at www.sciencedirect.com ScienceDirect

www.elsevier.com/locate/procedia

www.elsevier.com/locate/procedia

www.elsevier.com/locate/procedia

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. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Effects of hydrogen pressure, test frequency and test temperature on fatigue cra k growth properties of low-carbon steel i gaseous hydrogen Junichiro Yamabe a,b,c *, Michio Yoshikawa b , Hisao Matsunaga b,c,d , Saburo Matsuoka b a International Research Center for Hydrogen Energy, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka-shi, 819-0395, Japan b Research Center for Hydrogen Industrial Use and Storage, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka-shi, 819-0395, Japan c International Institute for Carbon-Neutral Energy Research, Kyushu Universit, 744 Moto-oka, Nishi-ku, Fukuoka-shi, 819-0395, Japan d Department of Mechanical Engineering, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka-shi, 819-0395, Japan Fatigue crack growth (FCG) tests for compact tension (CT) specimens of an annealed, low-carbon steel, JIS-SM490B were performed under various co binations of hydrogen pressures ranging from 0.1 to 90 MP , test frequencies fr m 0.001 to 10 Hz and test temperatures of room emperature (RT), 363 K and 423 K. In the hydrogen pressures of 0.1, 0.7 and 10 MPa at RT, the FCG rate increased wit a decrease in the t st frequency; then, peaked out. In the lower t st frequency egime, the FCG rate decr ased and became nearly equivalent to the FCG rate in air. Also, in hydrogen pressure of 45 MPa at RT, the hydrogen-assisted FCG acceleration showed an upper limit around the test frequencies of 0.01 to 0.001 Hz. On the other hand, in the hydrogen pressure of 90 MPa at RT, the FCG rate monotonically increased with a decrease in the test frequency, and eventually the upper limit of FCG acceleration was not confirmed down to the test frequency of 0.001 Hz. In the hydrogen pressure of 0.7 MPa at the test frequency of 1 Hz and temperatures of 363 K and 423 K, the stress intensity factor range, Δ K , for the onset of the FCG acceleration in hydrogen gas was shifted to a higher Δ K with an increase in the test temperature. The laser-microscope observation at specimen surface revealed that the hydrogen-assisted FCG acceleration always accompanied a localization of plastic deformation near crack tip. These results infer that the influencing factor dominating the hydrogen-assisted FCG acceleration is not the presence or absence of hydrogen in material but is how hydrogen localizes near the crack tip. Namely, a steep gradient of hydrogen concentration can result in the slip localization at crack tip, which enhances the Hydrogen Enhanced Successive Fatigue Crack Growth (HESFCG) proposed by the authors. It is proposed that such a peculiar dependence of FCG rate on hydrogen pressure, test frequency and test temperature can be unified by using a novel parameter representing the gradient of hydrogen concentration near crack tip. © 2016 The Authors. Published by Elsevier B.V. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Effects of hydrogen pressure, test frequency and test temperature on fatigue crack growth properties of low-carbon steel in gaseous hydrogen Junichiro Yamabe a,b,c *, Michio Yoshikawa b , Hisao Matsunaga b,c,d , Saburo Matsuoka b a International Research Center for Hydrogen Energy, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka-shi, 819-0395, Japan b Research Center for Hydrogen Industrial Use and Storage, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka-shi, 819-0395, Japan c International I stitute for Carbon-Neutral Energy Research, Kyushu Universit, 744 Moto-oka, Nishi-ku, Fukuok -shi, 819-0395, Japan d Department of Mechanical Engineering, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka-shi, 819-0395, Japan Abstract Fatigue crack growth (FCG) tests for compact tension (CT) specimens of an annealed, low-carbon steel, JIS-SM490B were performed under various combinations of hydrogen pressures ranging from 0.1 to 90 MPa, test frequencies from 0.001 to 10 Hz and test temperatures of room temperature (RT), 363 K and 423 K. In the hydrogen pressures of 0.1, 0.7 and 10 MPa at RT, the FCG rate increased with a decrease in the test frequency; then, peaked out. In the lower test frequency regi e, the FCG rate decreased and became nearly equivalent to the FCG rate in air. Also, in hydrogen pressure of 45 MPa at RT, the hydrogen-assisted F acceleration showed an upper limit around the test frequencies of 0.01 to 0.001 Hz. On the other hand, in the hydrogen pressure of 90 MPa at RT, the FCG rate monotonically increased with a decrease in the test frequency, and eventually the upper limit of FCG acc leration was not confirmed down to the test frequency of 0.001 Hz. In he hydrogen pr ssure of 0.7 MPa at the test frequency of 1 Hz and temperatures of 363 K nd 423 K, the stress intensity f ctor range, Δ K , for the onset of the FCG acceleration in hy rogen gas was s ift to a higher Δ K with an increase in the test emper ure. The laser-microscope observation at specimen surface revealed that the hydrogen-assisted FCG acceleration al ays accompanied a localization f plastic deform tion near crack tip. These results infer that the influencing factor dominating the hydrogen-assisted FCG acceleration is not the presence or absence of hydrogen in material but is how hydrogen localizes near the crack tip. Namely, a steep gradient of hydrogen concentration can result in the slip localization at crack tip, which enhances the Hydrogen Enhanced Successive Fatigue Crack Growth (HESFCG) proposed by the authors. It is proposed that such a peculiar dependence of FCG rate on hydrogen pressure, test frequency and test temperature can be unified by using a novel parameter representing the gradient of hydrogen concentration near crack tip. © 2016 The Authors. Published by Elsevier B.V. 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 responsi ility of the Sci ntific Committee of ECF21. © 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. Abstract

* 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 ECF21. * Corresponding author. Tel.: +81-92-802-3247; fax: +81-92-802-3921. E-mail address: yamabe@mech.kyushu-u.ac.jp 2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. * Corresponding author. Tel.: +81-92-802-3247; fax: +81-92-802-3921. E-mail address: yamabe@mech.kyushu-u.ac.jp

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.2016.06.068