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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 Monte Carlo Simulation to Predict Fracture Initiation in Mild Steel Yoshiki Nemoto 1 *, Kazuki Shibanuma 1 , Katsuyuki Suzuki 2 , Shuji Aihara 1 1 Department of System Innovation, the University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, Japan 2 Research into Artifacts, Center for Engineering, The University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa, Chiba, 277-8563 Japan. Abstract The brittle fracture occurs suddenly and can cause the fatal accident, so it needs to be prevented. The brittle fracture has been studied by a lot of researchers, but the quantitative relationship between fracture toughness and microstructure has not become clear. In this study, w developed the numerical model to predict cleavage fracture toughness f mild steel by integrating the formulation in previous studies. Besides, the proposed model was validated by comparing the predicted results with the experimental results. The three-point bending tests with notched specimen were conducted and the fracture initiation sites were observed by SEM in order to validate the proposed model. The predicted fracture toughness values showed good agreement with those of the experiments. The fracture initiation sites which the model predicted also show good agreement with them. It is found that the proposed model represents the quantitative relationship between fracture toughness and microstructure of mild steel and predicts fracture toughness with high accuracy. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: Fracture toughness, Fracture initiation, Cleavage fracture, Monte Carlo mrthod, Mild steel 1. Int oduction The brittle fracture occurs suddenly and can cause the fatal accident, so it needs to be prevented. It is said that the brittle fracture depends on the weakest part by Lin (1987) and it is also said that the brittle fracture toughness has the scatter by Wallin (1987). Beremin (1987) and Penau et al . (2006) introduced the stress parameter which is based on Weibull distribution to evaluate the scatter of fracture toughness. This theory is called “Beremin model” and a lot of researches has been done based on Beremin model because it enables to quantify the scatter and the size effect from Bordet et al . (2005). Valiente et al . (2005) proposed probability fracture model of ferrite pearlite steel. However, 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Monte Carlo Simulation to Predict Fracture Initiation in Mild Steel Yoshiki Nemoto 1 *, Kazuki Shibanuma 1 , Katsuyuki Suzuki 2 , Shuji Aihara 1 1 Department of System Innovation, the University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, Japan 2 Research into Artif cts, Center for Engineering, The University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa, Chiba, 277-8563 Japan. Abstract The brittle fracture occurs suddenly and can cause the fatal accident, so it needs to be prevented. The brittle fracture has been studied y a lot of researchers, but the quantitative r lationship between fracture toughn ss and microstructur has not become clear. In this study, w dev loped the numer c l model t predict cleavage fracture toughness of mild eel by integrating the formulation in previous studi s. Besides, th proposed m del was validat d by comparing the pred cted results with the experimental results. The thr e-point bending tests with notched spec men were conducted and the fracture initiation sites were obs ved by SEM in ord r to validate the propo ed model. T predi ted fracture toughn ss values showed good agreement with those of the experiments. The fracture initiation sites which t mo el predi ted also s ow good agreement with them. It is found at the proposed odel repr sents the quantitative relationship between fra ure toug ness an microstructure of mild steel and predicts f actur toughness with hig accuracy. © 2016 The Auth rs. Published by Elsevier B.V. Peer-review under espons bility of the Scientific Committee of ECF21. Keywords: Fracture toughness, Fracture initiation, Cleavage fracture, Monte Carlo mrthod, Mild steel 1. Introduction Th brittle fract re occurs suddenly a d can cause the fatal accid nt, so it needs to be prevented. It is said that the brittle frac ure depends on the weakest part by Lin (1987) nd it is also said that the brittle fracture toughness s t sca t r by Wallin (1987). Ber min (1987) and Pe au et al . (2006) intr duced the stress parame e which is based on Weibull distribution to evaluate the scatter of fracture oughness. This theory is call d “Bere in model” and a lot of researches has bee d ne based on Beremin model b ca se it enables to quantify th scatter and the size effect from Bordet et al . (2005). Valiente et al . (2005) proposed probab lity fracture model of f rrite p arlite st el. How ver, Copyright © 2016 The Authors. Published by Elsevier B.V. This is an open acces ar icle under the CC BY-NC-ND license (http://creativec mmons.org/licenses/by-nc-nd/4.0/). Peer-review und r responsibility of the Scientific Committee of ECF21. © 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: nemoto@struct.t.u-tokyo.ac.jp * Corresponding author. Tel.: +81-3-5841-6554. E-mail address: nemoto@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 under 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.2016.06.312