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) 1751–1755 Available online at www.sciencedirect.com Structural Integrity Procedia 0 (20 8) 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 3D Stress Fields Versus Void Distributions Ahead Of a Notch Tip For Semi-crystalline Polymers L. Laiarinandrasana a, ∗ , N. Selles a , Y. Cheng b , L. Helfen b,c , T.F. Morgeneyer a a PSL-Research University, MINES ParisTech, MAT-Centre des Mate´riaux, CNRS UMR7633, BP 87, F-91003 Evry Cedex, France b European Synchrotron Radiatio Facility (ESRF), BP 220, F-38043 Gre oble Cedex, France c Institute for Photon Science and Synchrotron Radiation (IPS), Karlsruhe Institute of Technology (KIT), D-76344 Eggenstein-Leopoldshafen, Germany Abstract The creep durability of engineeri g structures relies on the theory of Fracture Mechanics for Creeping Solids (FMCS). The studied material is a semi-crystalline polymer. The lifespan of plastic pipes being generally specified in terms of years of service, its prediction requires reliable constitutive models accounting for time dependent deformation under multiaxial stress states and failure criteria based on the mechanisms of damage and failure. Here, an experimental approach was developed so as to analyze the mechanisms of deformation and cavitation at the microstructural scale by using 3D imaging (tomography / laminography). Three stress triaxiality ratios were addressed using various notched specimen geometries. The void characteristic dimensions (volume fractio , height and diameter) w e then measured by defining a volume of interest. The sp tial distributions of these chara teristics at a prescribed creep time w re o served to be dependent on the stress triaxiality r tio. A finite element constitutive model using the porosity as an internal variable, was selected. Comparison of the multiscale experimental database with those simulated at the macroscopic scale as well as at the microstructure level was satisfactory. In the light of the finite element results, the principal stress singularities ere in good agreement with the void characteristic lengths. c 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: Type your keywords here, separated by semicolons ; © 2018 The Authors. Published by Els vier B.V. Peer-review under responsibil ty f the ECF22 organizer . ECF22 - Loading and Environmental e ff ects on Structural Integrity 3D Stress Fields Versus Void Distributions Ahead Of a Notch Tip For Semi-crystalline Polymers L. Laiarinandrasana a, ∗ , N. Selles a , Y. Cheng b , L. Helfen b,c , T.F. Morgeneyer a a PSL-Research University, MINES ParisTech, MAT-Centre des Mate´riaux, CNRS UMR7633, BP 87, F-91003 Evry Cedex, France b European Synchrotron Radiation Facility (ESRF), BP 220, F-38043 Grenoble Cedex, France c Institute for Photon Science and Synchrotron Radiation (IPS), Karlsruhe Institute of Technology (KIT), D-76344 Eggenstein-Leopoldshafen, Germany Abstract The creep durability of engineering structures relies on the theory of Fracture Mechanics for Creeping Solids (FMCS). The studied material is a semi-crystalline polymer. The lifespan of plastic pipes being generally specified in terms of years of service, its prediction requires reliable constitutive models accounting for time dependent deformation under multiaxial stress states and failure criteria based on the mechanisms of damage and failure. Here, an experimental approach was developed so as to analyze the mechanisms of deformation and cavitation at the microstructural scale by using 3D imaging (tomography / laminography). Three stress triaxiality ratios were addressed using various notched specimen geometries. The void characteristic dimensions (volume fraction, height and diameter) were then measured by defining a volume of interest. The spatial distributions of these characteristics at a prescribed creep time were observed to be dependent on the stress triaxiality ratio. A finite element constitutive model using the porosity as an internal variable, was selected. Comparison of the multiscale experimental database with those simulated at the macroscopic scale as well as at the microstructure level was satisfactory. In the light of the finite element results, the principal stress singularities were in good agreement with the void characteristic lengths. c 2018 The Authors. Published by Elsevier B.V. r-review under responsibility of the ECF22 organizers. Keywords: Type your keywords here, separated by semicolons ;

© 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016.

1. Introduction 1. Introduction

Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation.

Engineering structures made of semi-crystalline polymers are subjected to complex thermo-mechanical loadings. Lifetime prediction in terms of years of service for these industrial structures requires reliable constitutive models of time dependent deformation and multiaxial stress states. Here, a multiscale experimental approach was developed on notched and pre-cracked specimens. The results combined macroscopic data consisting of the creep displacements and data sets at the microstructural scale by using 3D imaging (tomography / laminography). A better understanding of the Engineering structures made of semi-crystalline polymers are subjected to complex thermo-mechanical loadings. Lifetime prediction in terms of years of service for these industrial structures requires reliable constitutive models of time dependent deformation and multiaxial stress states. Here, a multiscale experimental approach was developed on notched and pre-cracked specimens. The results combined macroscopic data consisting of the creep displacements and data sets at the microstructural scale by using 3D imaging (tomography / laminography). A better understanding of the

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. ∗ Correspon ing author. Tel.: + 33-1-60-76-30-64; fax: + 33-1-60-76-31-50. E-mail address: lucien.laiarinandrasana@mines-paristech.fr 2210-7843 c 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. ∗ Corresponding author. Tel.: + 33-1-60-76-30-64; fax: + 33-1-60-76-31-50. E-mail address: lucien.laiarinandrasana@mines-paristech.fr 2210-7843 c 2018 The Authors. Published by Elsevier B.V. Peer-revi w under responsibility of the ECF22 orga izers. * 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. 10.1016/j.prostr.2018.12.367