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 Structural Integrity 13 (2018) 1006–1 9 Available online at www.sciencedirect.com Structural Integrity Procedia 0 (20 8) 0– 0 Available online at www.sciencedirect.com Structural Integrity 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 e ff ects on Structural Integrity Influence of Hydrogen for Crack Formation during Mechanical Clinching Daisuke Sasaki a, ∗ , Yuki Tampa b , Toru Kato b a National Institute of Technology, Kurume College, 1-1-1 Komorino, Kurume, Fukuoka, 830-8555, Japan b National Institute of Technology, Ishikawa College, Kitacyujo, Tsubata, Ishikawa, 929-0392 Japan Abstract Hydrogen intrudes into the steel during pickling process which is a pre-processing before a joining process, promoting crack formation. In a mechanical clinching which is one of joining method in the automotive industry, cracks due to large strain sometimes forms. In order to guarantee reliability, it is important to clarify the influence of hydrog n on crack formation of the joint. In this study, we clarified the influence of hydrogen for the crack formati n on the mechanical clinching. Hydrogen charge was carried out using an electrolytic cathode charge. After the charging, mechanical clinching was performed. Mechanical clinching was carried out with steel plate and aluminium alloy plate. To clarify the influence of hydrogen, mechanical clinching was conducted without hydrogen charring. To investigate the crack formation, the test piece was cut and the cut surface was observed. When the joint was broken during the clinching, the fracture surface was observed using an optical microscope and an electron microscope. The load displacement diagram showed that without hydrogen charging, the compressive load increased as the displacement increased. On the other hand, the compressive load temporarily decreased with high hydrogen charging, suggesting that cracks formed at the time. The cut surface observation showed that interlock was formed in both cases with low hydrogen charging and without hydrogen charging. With low hydrogen charging, no cracks were formed in the joint. When high hydrogen charging was performed, cracks were formed at the joining point. Fracture analysis showed brittle-like fracture surface. These results indicate that hydrogen induces crack formation in the mechanical clinching. c ⃝ 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: Mechanical Clinching; Hydrogen Embrittlement; Crack Formation; © 2018 The Auth rs. Published by Elsevier B.V. Peer-review under responsibility of he ECF22 organizers. ECF22 - Loading and Environmental e ff ects on Structural Integrity Influence of Hydrogen for Crack For ation during echanical Clinching Daisuke Sasaki a, ∗ , Yuki Tampa b , Toru Kato b a National Institute of Technology, Kurume College, 1-1-1 Komorino, Kurume, Fukuoka, 830-8555, Japan b National Institute of Technology, Ishikawa College, Kitacyujo, Tsubata, Ishikawa, 929-0392 Japan Abstract Hydrogen intrudes into the steel during pickling process which is a pre-processing before a joining process, promoting crack formation. In a mecha ical clinching which is one of joining method in the automotive industry, cracks due t large strain somet mes forms. In order to guarantee reliability, it is important to clarify the influence of hydrogen on crack formation of the joint. In this study, we clarified the influence of hydrogen for the crack formation on the mechanical clinching. Hydrogen charge was carried out using an electrolytic cathode charge. After the charging, mechanical clinching was performed. Mechanical clinching was carried out with steel plate and aluminium alloy plate. To clarify the influence of hydrogen, mechanical clinching was conducted without hydrogen charring. To investigate the crack formation, the test piece was cut and the cut surface was observed. When the joint was broken during the clinching, the fracture surface was observed using an optical microscope and an electron microscope. The load displacement diagram showed that without hydrogen charging, the compressive load increased as the displacement increased. On the other hand, the compressive load temporarily decreased with high hydrogen charging, suggesting that cracks formed at the time. The cut surface observation showed that interlock was formed in both cases with low hydrogen charging and without hydrogen charging. With low hydrogen charging, no cracks were formed in the joint. When high hydrogen charging was performed, cracks were formed at the joining point. Fracture analysis showed brittle-like fracture surface. These results indicate that hydrogen induces crack formation in the mechanical clinching. c ⃝ 2018 The Author . Published by Elsevi B.V. r-review und r responsibil ty of the ECF22 organizers. Keywords: Mechanical Clinching; Hydrogen Embrittlement; Crack Formation;

© 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.

1. Introduction 1. Introduction

In recent years, weight reduction and safety improvement on transportation machinery progress. To promote them, the aluminium which is one of high specific strength materials is useful. However, the joining is di ffi cult due to di ff erent melting point and a weak intermetallic compound. Therefore, the development of joining method with cold working and high productivity is expected. Mechanical clinching is focused as one of cold joining methods In recent years, weight reduction and safety improvement on transportation machinery progress. To promote them, the aluminium which is one of high specific strength materials is useful. However, the joining is di ffi cult due to di ff erent melting point and a weak intermetallic compound. Therefore, the development of joining method with cold working and high productivity is expected. Mechanical clinching is focused as one of cold joining methods

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. ∗ Corresponding author. Tel.: + 81-942-35-9375 ; fax: + 81-942-35-9425. E-mail address: d-sasaki@kurume-nct.ac.jp 2210-7843 c ⃝ 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. ∗ Corresponding author. Tel.: + 81-942-35-9375 ; fax: + 81-942-35-9425. E-mail address: d-sasaki@kurume-nct.ac.jp 2210-7843 c ⃝ 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. * 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. 10.1016/j.prostr.2018.12.187