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) 1845–1854 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. ECF22 - Loading and Environmental effects on Structural Integrity Clarification of micromechanism on Brittle Fracture Initiation Condition of TMCP Steel with MA as the trigger point Atsuhisa Kitade a ,Tomoya Kawabata a ,Shintaro Kimura b Hideaki Takatani c , Kiyoshi Kagehira c and Tatsuki Mitsuzumi c a The University of Tokyo, 7-3-1 Bunkyo, Tokyo, 113-8656, Japan b Mitsubishi Heavy Industries, 2-1-1 Shimahama, Arai-machi, Takasago, Hyogo, 676-8686, Japan c Primetals Technologies Japan, 4-6-22 Ka onshinmachi, Hiroshima, 733-8553,Japan Brittle fracture of carbon steel has a serious effect on the safety of steel structures. In case of bainitic microstructure it is well known that MA works as a triggering point of brittle fracture. However, the brittle fracture prediction procedure has not been fixed yet because of its complexity of the microstructure. The target of this series of research is to clarify the selection rule of the MA which causes brittle fracture from a number of MAs in the bainitic steel manufactured by TMCP process. Double-notch tests was carried out to identify the true trigger point of brittle fracture comparing with a simple whole cleavage fracture surface observation. Then, with respect to the nucleus of fracture occurrence, orientation information data of crystals acquired by EBSD was investigated after surface processing using FIB polishing. As a result, it was revealed that brittle crack occurred from the MA located in the much more coarse crystal grain than the surrounding grains. Furthermore, according to the GROD (Grain Reference Orientation Deviation) map, a large amount of piled-up dislocations is observed around MA which worked as the trigger of brittle crack initiation. This observation will help an establishment of quantitative model which can explain the behavior of brittle fracture in TMCP steel. Authors also established numerical simulation model of DWTT test used in quality assurance in line pipe field. © 2018 The Authors. Published by Els vier B.V. Peer-review under responsibility of the ECF22 organizers. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. ECF22 - Loading and Environmental effects on Structural Integrity Clarification of micromechanism on Brittle Fracture Initiation Condition of TMCP Steel with MA as the trigger point Atsuhisa Kitade a ,Tomoya Kawabata a ,Shintaro Kimura b Hideaki Takatani c , Kiyoshi Kagehira c and Tatsuki Mitsuzumi c a The University of Tokyo, 7-3-1 Bunkyo, Tokyo, 113-8656, Japan b Mitsubishi Heavy Industri s, 2-1-1 Shimahama, Arai-machi, Takasago, Hyogo, 676-8686, Japan c Primetals Technologies Japan, 4-6-22 K nonshinmachi, Hiroshima, 733-8553,Japan Abstract Brittle fracture of carbon steel has a serious effect on the safety of steel structures. In case of bainitic microstructure it is well known that MA w rks as a triggering point f brittle fractur . However, the brittle fracture pr diction procedu e has not been fix d yet because of its complexi y of the microstructure. The target of thi series of research is to clarify the selection rule of the MA which causes brittle fracture from a number of MAs in the bainitic steel manufactured by TMCP process. Double-notch tests was carried o t to identify the true trigger point of brittle fracture comparing with simple whole cl avag fractur surface observation. Then, w th resp ct to the nucleus of fractur oc urr n e, orientation infor atio data of crystals a quire by EBSD was investigated aft r surface processing using FIB polishing. As a result, it was revealed th t brittle crack occurred from he MA located in he much more c a se crystal grain than the urrounding grains. Furth rmore, accord ng to the GROD (Grain Reference Orienta ion Deviation) m p, a larg amount of piled-up dislocations is observed a ound MA which worked as the trigg r of brittle crack initiation. This observation will help an establishment of quantitative model which can explain the behavior of br tle fracture in TMCP steel. Authors also establi hed numerical simulation model of DWTT test us i quality assur nce in line pipe field. © 2018 The Au hors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Abstract

© 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: Brittle fracture TMCP bainitic ste l FIB and flush polishing EBSD Keywords: Brittle fracture TMCP bainitic steel FIB and flush polishing EBSD

Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation. * Corresponding author. Tel : +81-80-6709-0167 ; fax : +81-42-576-6530 . E-mail ad ress: kitade@fract.t.u-tokyo.ac.jp * Corresponding author. Tel : +81-80-6709-0167 ; fax : +81-42-576-6530 . E-mail address: kitade@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.2018.12.330