PSI - Issue 13

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com ienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structural Integrity 13 (2018) 1183–1188 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 Dynamic measurement of CTOA of unstable ductile fracture of high pressure gas pipelines Hikaru Yamaguchi a , Takahiro Hosoe a , Kazuki Shibanuma a , Shuji Aihara a, * a The University of Tokyo, 7-3-1, Hongo, Bunkyo, Tokyo, 113-8656, Japan Abstract Demand for natural gas is increasing worldwide and pressure and diameter of gas pipelines are increasing. In such high-pressure gas pipelines, prevention of unstable ductile fracture is an important issue. Crack tip opening angle (CTOA) is widely used for fracture criterion of unstable ductile fracture, and measured by Drop Weight Tear T st (DWTT). But, measuring CTOA during dynamic crack propagation in pipe burst is very limited. Therefore, in this study, we measured CTOA in a pipe burst test. The crack propagation was photographed by high-speed camera. The CTOA values by the DWTT and the burst tests were found somewhat different. A care should be taken when using CTOA value obtained by DWTT for analyzing dynamic crack propagation behavior in pipelines. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: Unstable ductile fracture; Crack tip opening angle; Drop weight tear test; Pipe burst test 1. Introduction Demand for natural gas has be n increasing due to l ss carbon di-oxide emission and more secure production recently. According to this trend, higher amount of gas has to be transported. To realize this, demand for larger diameter and higher-pressure natural gas pipelines are increasing. Prevention of large-scale failure is crucially important for these pipelines. One of the failure modes of high-pressure gas pipelines is unstable ductile fracture. One of the most famous methods for evaluating unstable ductile fracture is the two-curve method (TCM), developed by Battelle Memorial Institute [1]. The TCM is simple and easy to handle but it cannot predict actual crack propagation ECF22 - Loading and Environmental effects on Structural Integrity Dynamic measurement of CTOA of unstable ductile fracture of high pressure gas pip lines Hikaru Yamaguchi a , Takahiro Hosoe a , Kazuki Shibanuma a , Shuji Aihara a, * a The University of Tokyo, 7-3-1, Hongo, Bunkyo, Tokyo, 113-8656, Japan Abstract Demand for natural gas is increasing worldwide and pressure and diameter of gas pipelines are increasing. In such high-pressure gas pipelines, prevention of unstable ductile fracture is an important issue. Crack ti opening a gl (CTOA) is widely us d for fracture criterion of unstable ductile fracture, and measured by Drop Weight Tear Test (DWTT). But, measuring CTOA during dynamic crack propagati n in pipe burst is very limited. Therefore, in this study, we m asured C OA in a pipe burst test. The crack propagation was photographed by high-speed ca era. The CTOA values by the DWTT and the burst tests were found somewhat different. A care s uld be taken when using CTOA value obtained by DWTT for analyzi g dynamic crack propagation behavior in pip lines. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: Unstable ductile fracture; Crack tip opening angle; Drop weight tear test; Pipe burst test 1. Introduction Demand for natural gas has been ncreasing due to l ss carbon di-oxide mission and more secure p oduction recently. According to this trend, higher amount of gas has to be transported. To realize this, demand for larger diameter and higher-pressure natural gas pipelines are increasing. Prevention of large-scale failure is crucially important for these pipelines. One of the failure modes of high-pressure gas pipelines is unstable ductile fracture. One of the most famous methods for evaluating unstable ductile fracture is the two-curve method (TCM), developed by Battelle Memorial Institute [1]. The TCM is simple and easy to handle but it cannot predict actual crack propagation © 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.: 81-3-5841-6505. E-mail address: aihara@fract.t.u-tokyo.ac.jp * Corresponding author. Tel.: 81-3-5841-6505. E-mail ad ress: ai a a@fract.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 organizers.

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.2018.12.245