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) 116–122 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. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. ECF22 - Loading and Environmental effects on Structural Integrity Investigation on brittle crack propagation and arrest behaviour under high crack driving force in steel Fuminori Yanagimoto a* , Kazuki Shibanuma a , Teppei Okawa b , Katsuyuki Suzuki c , Shuji Aihara a a Department of Systems Innovation, Graduate School of Engineering, the University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, Japan b Plate & Shape Research Lab., Steel Research Laboratories, Nippon Steel & Sumitomo Metal Coopreration, 20-1 Shintomi, Futtsu-shi, Chiba, Japan c Research into Artifacts, Center for Engineering, the University of Tokyo, 5-1-5, Kashiwa-shi, Chiba, Japan Abstract The brittle crack propagation and arrest behaviors under high stress intensity factor conditions have been an unsolved problem in the fracture mechanics. Although a numerical model based on the local fracture stress criterion indicated growth of unbroken shear lips due to SIF increasing was a cause of the problem, such model depended on many assumptions and it lacked experimental discussion on the behaviors. This study carried out brittle crack arrest experiments under high SIF condition using wider specimens. The experiments and finite element analyses of them showed that the unbroken shear lip formation was governed by the effective SIF. The numerical model was modified based on this result and the predictions by the modified model showed better agreement with the exp rimental results than those by th co ventional model. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of th ECF22 organizers. Keywords: Brittle crack propagation and arrest behavior; Rapid crack propagation; Steel; 1. Introduction Since brittle fracture sometimes causes serious damage in large steel structures, the crack arrestability is the important property as well as the resistance against crack initiation (Sumi et al., 2013). Recently, the required crack arrestability was defined in the international rule for the container ships. This rule presented that the requirement of the crack arrestability was ca ≥ 190 MPa√m ( 6,000 N mm 3/2 ⁄ ) for the steel plates whose thickness is thinner than 80 mm (International Association of Classification Societies, 2014). It is expected that the higher crack arrestability is required for steel plates whose thickness is thicker than 80 mm (Matsumoto et al., 2018). ECF22 - Loading and Environmental effects on Structural Integrity Investigation on brittle crack propagation and arrest behaviour under high crack driving force in steel Fuminori Yanagimoto a* , Kazuki Shibanuma a , Teppei Okawa b , Katsuyuki Suzuki c , Shuji Aihara a a Department of Systems Innovation, Graduate School of Engineering, the University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, Japan b Plate & Shape Research Lab., Steel Research Laborat ries, Nippon Steel & Sumitomo Metal C opreration, 20-1 Shint mi, Futtsu-shi, Chiba, Japan c Research into Artifacts, Cente for Engineering, h University of Tokyo, 5-1-5, Kashiwa-shi, Chiba, Japan Abstract The brittle crack propagation and arrest behaviors under high stress intensity factor conditions have been an unsolved problem in the fracture mechanics. Although a numerical model based on the local fracture stress criteri indicated growth of unbroken shear lips due to SIF increasing was a cause of the problem, such m del depended on many assumptions and it lacked experiment l discussion on the beh viors. This study carried out rittle crack arrest experim nts under high SIF condition using wi er specimens. The experiments and finite element analyses of them showed that the unbrok hear lip formation was gover ed by the ffective SIF. The numeric l model was modified ba ed on thi result and the predictio s by the m dified model showed better agre ment with the experimental results than those by the conventional mo el. © 2018 The Authors. Published by Elsevier B.V. Peer-review under esponsibility of the ECF22 organizers. Keywords: Brittle crack propagation and arrest behavior; Rapid crack propagation; Steel; 1. Introduction Since brittle fracture sometimes causes serious damage in large steel structures, the crack arrestability is the important property as w l as the r istance against crack initiation (Sumi et al., 2013). Recently, the required crack arrestability was defined in the international rule for he container ships. This rule presented that the requirement of the crack arrestability was ca ≥ 190 MPa√m ( 6,000 N mm 3/2 ⁄ ) for the steel plates whose thickness is thinner than 80 mm (International Association of Classification Societies, 2014). It is expected that the higher crack arrestability is required for steel plates whose thickness is thicker than 80 mm (Matsumoto et al., 2018). © 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.: +81-3-5841-6554 E-mail address : yanagimoto@struct.t.u-tokyo.ac.jp * Corresponding author. Tel.: +81-3-5841-6554 E-mail address : yanagimoto@struct.t.u-tokyo.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.2018.12.020