PSI - Issue 2_B

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 Struc ural Integrity 2 (2016) 2598–26 5 ScienceDirect Structural Integrity Procedia 00 (2016) 000–000 ScienceDirect Structural Integrity Procedia 00 (2016) 000–000 Available online at www.sciencedirect.com Available online at www.sciencedirect.com

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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. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Mod ling of Brittle Crack Propagation/A rest Behavior in Steel Plates Kazuki Shibanuma a *, Fuminori Yanagimoto a , Tetsuya Namegawa b , Katsuyuki Suzuki c , Shuji Aihara a a Dept. Systems Innovation, Graduate school of Engineering, the University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, Japan b Dept. Systems Innovation, Graduate school of Engineering, the University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, Japan (presently Nippon Steel & Sumitomo Metal Corporation) c Research into Artifacts, Center for Engineering, the University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa-shi, Chiba, Japan To prevent brittle cracks from causing fatal damage to steel structures, it is needed that steels have enough crack arrestability. However, the brittle crack propagation/arrest behavior has not been explained theoretically enough from the aspect of energy balance and especially the long crack problem has remained as an important unsolved issue for some decades. The authors propose a new model based on local fracture stress criterion to solve the long crack problem. The model considers crack closure effect by uncracked side ligaments formed due to relaxation of plastic constraint progressing with SIF increasing. A simultaneous equation composed of four equations, which formulate local fracture condition, strain hardening, yield point, and dynamic SIF considering side ligaments, is solved to simulate a crack propagation in the model. To validate the model, we compared model simulations with some experiments. Some of them were conducted under the long crack problem condition and obtained the result that they showed good agreements, even under the long crack problem condition. This implies the long crack problem can be explained from the aspect of side ligament development due to the relaxation of plastic constraint. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Modeling of Brittle Crack Propagation/Arrest Behavior in Steel Plates Kazuki Shibanuma a *, Fuminori Yanagimoto a , Tetsuya Namegawa b , Katsuyuki Suzuki c , Shuji Aihara a a Dept. Systems Innovation, Graduate school of Engineering, the University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, Japan b t. st s I ti , r t s l of i ri , t i rsit of o o, - - , , - , , (presently Nippon St el & Sumitomo Metal C rp ration) c Research into Artifacts, Center for Engineering, the University of T kyo, 5-1-5, Kashiwanoha, Kashiwa-shi, Chiba, Japan Abstract To prevent brittle cracks from causing fatal damage to steel structures, it is needed that steels have enough crack arrestability. H wever, he brittle rack prop gation/ rrest behavior has no been xplained th oretically enough fr m t e spect of energ balance and specially the long cr ck problem has remained as an importa t unsolv d issue for some decad s. The authors propose a new mod bas d on local fra ture stress criterion to solve the long crack problem. The o el co iders crack cl sure effect by u cracked side ligaments fo med due to relaxat of plastic constraint progressing with SIF increa ng. A si ultaneous qua ion composed of four equations, which formulate local fracture condi ion, strain hardening, yield point, a d dynamic SIF considering side ligaments, is solved to simulate a crack propaga ion in the model. To validate the model, we compared model simulations with some xperiments. Some of them were conducted under the long crack problem con ition and obt ined the result that they sh wed good agreements, even under the l g rack problem c dition. This implies the long crack problem can b explained from th aspect of side ligam nt developm nt due to the relaxation of plastic constra nt. © 2016 The Authors. Published by Elsevier B.V. Peer-review under esponsibility of the Scientific Committee of ECF21. 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-n -nd/4.0/). Peer-review under responsibility of the Scientific Committee of ECF21. Abstract

© 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: "brittle crackl propagation;local fracture stress;ESSO tests;steel;crack arrest" Keywords: "brittle crackl propagation;local fracture stress;ESSO tests;steel;crack arrest"

Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation.

* Corresponding author. Tel.:+81-3-5841-6565. E-mail address: shibanuma@struct.t.u-tokyo.ac.jp * Corresponding author. Tel.:+81-3-5841-6565. E-mail address: shibanuma@struct.t.u-tokyo.ac.jp

* Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review un r responsibility of the Scientific Committee of ECF21. 2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer review under r sponsibility of the Scientific Committee of ECF21.

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.2016.06.325