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) 1873–1878 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 Creep-Fatigue Life Prediction of 316H Stainless Steel by Utilizing Non-Unified Constitutive Model Takehiro Shimada a , Kenji Tokuda a , Kimiaki Yoshida a , Nobutada Ohno b , Tatsuya Sasaki c a IHI Corporation, Yokohama, Japan b Nagoya industrial Science Research Institute, Nagoya, Japan c Department of Computational Science and Engineering, Nagoya University, Nagoya, Japan True stress and strain are necessary to estimate the rupture life under creep-fatigue conditions. Finite element analysis (FEA) is one of the most reliable method to calculate true stress and strain, but the accuracy of the obtained result is often greatly dependent on the constitutive model used. Non-unified constitutive model has been proposed, where inelastic strain is decomposed into creep strain and visco-plastic strain. In this paper, a cyclic hardening effect and a plastic strain range dependency were introduced into the non-unified constitutive model to predict the creep-fatigue damage of 316H stainless steel. This model was implemented in a finite element program and FEA were conducted to develop a life assessment method and calculate the creep-fatigue damage by modified ductile exhaustion method. As a consequence, it was vealed that the p dicted creep-fatigue lives showed high correspondenc wit th experime tal results by the modifie ductile exhaustion me hod utilizing th on-unified constitutiv model. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: 316H steel; Creep fatigue; Constitutive model; Creep-fatigue is a principal failure mechanism of components operating at elevated temperatures.. Safe and accurate methods to predict cr ep-fatigue damage are therefore required in order to assess the reliability of such components. A number of assessment procedures, e.g. RCC-MR(2002) and ASME Sec.III(2010), are available for this purpose. But in the procedure simplified methods are used and therefore give a conservative, in some cases too conservative, estimation.. Fully inelastic analysis is one of the methods to overcome it. However it is quite difficult to calibrate material parameter for the analysis. Non-unified constitutive model has been proposed, where inelastic strain is decomposed into creep strain and visco-plastic strain. It is relatively easier to determine the material parameters for © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. ECF22 - Loading and Environmental effects on Structural Integrity Creep-Fatigue Life Prediction of 316H Stainless Steel by Utilizing Non-Unified onstitutive Model Takehiro Shi ada a , Kenji Tokuda a , Kimiaki Yoshida a , Nobutada Ohno b , Tatsuya Sasaki c a IHI Corporation, Yokohama, Japan b Nagoya industrial Science Research Institute, Nagoya, Japan c Department of Computational Scienc and Engineeri g, Nagoy University, Nagoya, Japan Abstract True stress and strain are necessary to estimate the rupture life under creep-fatigue conditions. Finite element analysis (FEA) is one of the most reliable ethod to c lculate true stress and strain, but the accuracy of the obtai ed result is often greatly dependent on the constitutive model use . Non- nified constitutive model has been proposed, where inelastic strain is decomposed into creep strain and visco-plastic strain. In this paper, a cyclic hardening eff ct and a plastic strain range dependency were introduced into the non-unified con titutive model to redict the creep-fatigue damage of 316H stainless steel. This model was implement i a finite element program and FEA were conducted to develop a life ssessment method and calculate the creep-fatigu damage by modified ductile exhaustion method. As a onsequence, it was revealed that t e pre icted cre p-fatigue lives showed high correspon ence with the experimental results by the modified ductile exhaustion method utilizing the non-unified constitutive model. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: 316H steel; Creep fatigue; Constitutive model; 1. Introduction Creep-fatigue is a pri c pal failur mechanism of comp nents operating at elevated temperatures.. Safe and accurate methods to predict creep-fatigue damage are therefore required in order to assess the reliability of such components. A number of assessment procedures, e.g. RCC-MR(2002) and ASME Sec.III(2010), are available for this purpose. But in the procedure simplified methods are used and therefore give a conservative, in some cases too conservative, estimation.. Fully inelastic analysis is one of the methods to overcome it. However it is quite difficult to calibrate material parameter for the analysis. Non-unified constitutive model has been proposed, where inelastic strain is decomposed into creep strain and visco-plastic strain. It is relatively easier to determine the material parameters for © 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. Abstract 1. Introduction

* 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.2018.12.326