PSI - Issue 7

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 7 (2017) 376–382 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. Published 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 Effect of hydrogen on very high cycle fatigue behavior of a low strength Cr-Ni-Mo-V steel containing micro-defects Ning Wang, Long Jin, Ming-Liang Zhu*, Fu-Zhen Xuan, Shan-Tung Tu Key Laboratory of Pressure Systems and Safety, Ministry of Education; East China University of Science and Technology, 200237 Shanghai, China Abstract The role of hydrogen in fatigue failure of low strength steels is not as well understood as of high strength steels in very high cycle fatigue regime. In this work, axially cyclic tests on a low strength Cr-Ni-Mo-V steel with charged hydrogen were carried out up to the very high cycl fatigu regime under ultrasonic frequ ncy to exami e the degradation of fatigue strength and associated failure mechanisms. Results show that the S - N curves show a continuously decreasing mode and hydrogen-charged specimens have lower fatigue strength and shorter fatigue lifetime, as compared with as-received specimens. It is concluded that the hydrogen trapped by inclusions drives interior micro-defects as dominant crack initiation site, and has a clear link to the initiation and early growth of interior fatigue cracks. © 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: Low strength steel; Very high cycle fatigue; Non-metallic inclusion; Crack initiation; Hydrogen 1. Introduction In many industries, the required design lifetime of key components often exceeds 10 7 cycles. A large number of research results have shown fatigue failure can occur beyond 10 7 cycles named as very high cycle fatigue (VHCF) 3rd International Symposium on Fatigue Design and Material Defects, FDMD 2017, 19-22 September 2017, Lecco, Italy Effect of hydrogen on very high cycle fatigue behavior of a l w strength Cr-Ni-Mo-V steel containing micro-defects Ning Wang, Long Jin, ing-Liang Zhu*, Fu-Zhen Xuan, Shan-Tung Tu Key Laboratory of Pressure Systems and Safety, Ministry of Education; East China University of Science and Technology, 200237 Shanghai, China Abstract The role of hydrogen in fatigue failure of low strength ste ls is not as well u derstood as of high stren th ste ls in very high cycle tigue regime. In this work, axially cyclic tests on a low strength Cr-Ni-Mo-V st el with charge r e were carried out up to the very high cycle fatigue regime under ultrasonic fr quen y to examine the d gradation of fatigue strength an associated failure mechanisms. Res lts show that the S - N curves show a c nti uously decreasing mode and hydrogen-charged specimens have lower fatigue strength and shorter fatigue lifetime, as compared with as-received specimens. It is concluded that the hydrogen trapped by inclusions drives interior micro-defects as dominant crack initiation site, and has a clear link to the initiation and early growth f interior fatigue cracks. © 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 D fects. Keywords: Low strength steel; Very high cycle fatigue; Non-metallic inclusion; Crack initiation; Hydrogen 1. Introduction In many industri , the required desig lifetime of k y components often exceeds 10 7 cycles. A large number of research results have shown fatigue failure can occur beyond 10 7 cycles named as very high cycle fatigue (VHCF) © 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.: +86-21-64253776; fax: +86-21-64253513. E-mail address: mlzhu@ecust.edu.cn

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.: +86-21-64253776; fax: +86-21-64253513. E-mail address: mlzhu@ecust.edu.cn

* 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.2017.11.102