PSI - Issue 13

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 Structu al Integrity 13 (2018) 868–876 Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2018) 000–000 Available online at www.sciencedirect.com Structural Integrity 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 e ff ects on Structural Integrity Validation of BS 7910; assessing the integrity of pipes containing axial flaws Konstantinos Kouzoumis a,c, ∗ , Isabel Hadley b , Mahmoud Mostafavi c a NSIRC, Granta Park, Great Abington, CB21 6AL, Cambridge, UK b TWI Ltd., Granta Park, Great Abington, CB21 6AL, Cambridg , UK c University of Bristol, Queens Building, University Walk, BS8 1TR, Bristol, UK Abstract The results of hundreds of large scale fracture tests have been collected from various sources and analyzed in accordance with the latest version of the BS 7910 fitness for service (FFS) standard a d, in selected cases, with R6 and / or the API 57 -1 / ASME FFS-1 fitness for service standard. This analysis aims to provide further validation of BS 7910 and identify where modification is needed. The tests cover a wide variety of materials, flaw geometries (surface, embedded, through thickness) and loadings (pressure, bending, residual stress), thus validating the standard over a wide spectrum of applications. All the tests are analyzed with the use of the basic assessment option (Option 1), which requires only the basic tensile properties and fracture toughness of the component, and selected tests are re-analyzed using more advanced methods. During the analysis, close attention was paid to the results of 173 tests on pipes with axial flaws, where an apparently arbitrary safety factor on reference stress is included in BS 7910, but not in other standards, leading to apparently lower defect-tolerance when BS 7910 is used. The history of this part of the standard, along with approaches used in other standards, was investigated. A modified equation, without this safety factor, was used in the analysis of the tests, where applicable, and compared with results from other standards. The comparison between the approaches shows the BS 7910 safety factor to be unnecessary, with all test results falling outside the failure assessment diagram (FAD), but with less conservatism, as they lie closer to it. c 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: Fitness For Service; BS 7910; Integrity assessment; R6; API 579-1 / ASME FFS-1 © 2018 The Auth rs. Published by Elsevier B.V. Peer-review under responsibility of he ECF22 organizers. ECF22 - Loading and Environmental e ff ects on Structural Integrity Validation of BS 7910; assessing the integrity of pipes containing axial flaws Konstantinos Kouzoumis a,c, ∗ , Isabel Hadley b , Mahmoud Mostafavi c a NSIRC, Granta Park, Great Abington, CB21 6AL, Cambridge, UK b TWI Ltd., Granta Park, Great Abington, CB21 6AL, Cambridge, UK c University of Bristol, Queens Building, University Walk, BS8 1TR, Bristol, UK Abstract The results of hundr ds of large scale fracture test have be n collected from various sources and analyzed in accordance with the latest version of the BS 7910 fitness for service (FFS) standa d and, in selected cases, with R6 and / or the API 579-1 / ASME FFS-1 fitness for service standard. This analysis aims to provide further validation of BS 7910 and identify where modification is needed. The tests cover a wide variety of materials, flaw geometries (surface, embedded, through thickness) and loadings (pressure, bending, residual stress), thus validating the standard over a wide spectrum of applications. All the tests are analyzed with the use of the basic assessment option (Option 1), which requires only the basic tensile properties and fracture toughness of the component, and selected tests are re-analyzed using more advanced methods. During the analysis, close attention was paid to the results of 173 tests on pipes with axial flaws, where an apparently arbitrary safety factor on reference stress is included in BS 7910, but not in other standards, leading to apparently lower defect-tolerance when BS 7910 is used. The history of this part of the standard, along with approaches used in other standards, was investigated. A modified equation, without this safety factor, was used in the analysis of the tests, where applicable, and compared with results from other standards. The comparison between the approaches shows the BS 7910 safety factor to be unnecessary, with all test results falling outside the failure assessment diagram (FAD), but with less conservatism, as they lie closer to it. c 2018 The Author . Published by Elsevi B.V. r-review und r responsibil ty of the ECF22 organizers. Keywords: Fitness For Service; BS 7910; Integrity assessment; R6; API 579-1 / ASME FFS-1

© 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.

1. Introduction 1. Introduction

Fitness for Service (FFS) Procedures, such as BS 7910, are built upon sound fracture mechanics principles and engineering data, and have been implemented by the engineering community for many decades, for purposes ranging from defect-tolerant design to life extension of safety-sensitive components. The basic concept in assessing a structure, follows the calculation of an assessment point with an abscissa designated L r , considered as proximity to plastic Fitness for Service (FFS) Procedures, such as BS 7910, are built upon sound fracture mechanics principles and engineering data, and have been implemented by the engineering community for many decades, for purposes ranging from defect-tolerant design to life extension of safety-sensitive components. The basic concept in assessing a structure, follows the calculation of an assessment point with an abscissa designated L r , considered as proximity to plastic

* Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt ∗ Corresponding author. Tel.: + 44-122-394-0401. E-mail address: k.kouzoumis@bristol.ac.uk ∗ Corresponding author. Tel.: + 44-122-394-0401. E-mail address: k.kouzoumis@bristol.ac.uk

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. 2210-7843 c 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. 2210-7843 c 2018 The Authors. Published by Elsevier B.V. Peer-revi w under responsibility of the ECF22 orga izers. 2452-3216  2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. 10.1016/j.prostr.2018.12.165