PSI - Issue 2_A

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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.2016.06.124 ∗ Corresponding author. Tel.: + 44-7547-669858. E-mail address: a.sa cho15@imperial.ac.uk 2452-3216 c 2016 The Auth rs. Publi hed by Elsevier B.V. e r-review under responsibil ty of the Scientific Committee of ECF21. ∗ Corresponding author. Tel.: + 44-7547-669858. E-mail address: a.sancho15@imperial.ac.uk 2452-3216 c 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. * Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt ∗ Corresponding author. Tel.: + 44-7547-669858. E-mail address: a.sancho15@imperial.ac.uk 2452-3216 c 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. 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 Experimental techniques for ductile damage characterisation A. Sancho a, ∗ , M.J. Cox a,b , T. Cartwright b , G.D. Aldrich-Smith b , P.A. Hooper a , C.M. Davies a , J.P. Dear a a Imperial College London, Department of Mechanical Engineering, London, SW7 2AZ, United Kingdom b AWE Plc., Materials Sci nce, Aldermaston, Reading, RG7 4PR, United Kingdom Abstract Ductile damage in metallic materials is caused by the nucleation, growth and coalesce of voids and micro-cracks in the metal ma trix when it is subjected to plastic strain. A considerable number of models have been proposed to represent ductile failure focusing on the ultimate failure conditions; however, only some of them study in detail the whole damage accumulation process. The aim of this work is to review experimental techniques developed by various authors to measure the accumulation of ductile damage under tensile loads. The measurement methods reviewed include: sti ff ness degradation, indentation, microstructure analysis, ultrasonic waves propagation, X-ray tomography and electrical potential drop. Sti ff ness degradation and indentation techniques have been tested on stainless steel 304L hourglass-shaped samples. A special interest is placed in the Continuum Damage Mechanics ap proach (CDM) as its equations incorporate macroscopic parameters that can represent directly the damage accumulation measured in the experiments. The other main objective lies in identifying the strengths and weaknesses of each technique for the assessment of materials subjected to di ff erent strain-rate and temperature conditions. c 2016 The Authors. Published by Elsevier B.V. Peer-r view under responsibility of the Scientific Committee of ECF21. Keywords: Ductile damage; Voids; CDM; Continuum Damage Mechanics; High strain-rate; Elasti modulus; In ntation; Ultrasonic w ves; X-ray tomography; Electrical p tential drop; DIC; Digital Image Correl tion, Stainless st el 304L. If a certain threshold plastic strain is achieved in a metallic material, defects like voids and micro-cracks start to nucleate. When further strain is applied they grow up to a point where they interact with each other, leading eventually to a macroscopic crack and fracture. The experimental measurement of this damage is not trivial, and di ff erent techniques have been proposed over the years with the aim of characterising ductile damage accumulation. This research is focused on the ductile damage evolution when tensile strain is progressively applied. The diverse techniques for its measurement are reviewed and some of them are tested on hourglass-shaped samples of stainless steel 304L. A methodology to characterise damage is proposed and the results obtained so far are presented. 21st European Confere ce on Fracture, ECF21, 20-24 Jun 2016, Catania, Italy Experimental tech iques for ductile damage characterisation A. Sancho a, ∗ , M.J. Cox a,b , T. Cartwright b , G.D. Aldrich-Smith b , P.A. Hooper a , C.M. Davies a , J.P. Dear a a Imperial College London, Department of Mechanical Engineering, London, SW7 2AZ, United Kingdom b AWE Plc., Materials Science, Aldermaston, Reading, RG7 4PR, United Kingdom Abstract Ductile damage in metallic m terials is caused by the nucleation, growth and coalesce of voids and micro-cracks in the metal ma trix when it is subjected to plastic strain. A considerable number of models have been proposed to represent ductile failure focusing on the ultimate failure conditions; however, only some of them study in detail the whole damage accumulation process. The aim of this work is to review experimental techniques developed by various authors to measure the accumulation of ductile damage under tensile loads. The measurement methods reviewed include: sti ff ness degradation, indentation, microstructure analysis, ultrasonic waves propagation, X-ray tomography and electrical potential drop. Sti ff ness degradation and indentation techniques have been tested on stainless steel 304L hourglass-shaped samples. A special interest is placed in the Continuum Damage Mechanics ap proach (CDM) as its equations incorporate macroscopic parameters that can represent directly the damage accumulation measured in the experiments. The other main objective lies in identifying the strengths and weaknesses of each technique for the assessment of materials subjected to di ff erent strain-rate and temperature conditions. c 2016 The Authors. Published by Elsevier B.V. Peer-review under r sponsibility of the Scientific Co mittee of ECF21. Keywords: Ductile damage; Voids; CDM; Continuum Damage Mechanics; High strain-rate; Elastic modulus; Indentation; Ultrasonic waves; X-ray tomography; Electrical potential drop; DIC; Digital Image Correlation, Stainless steel 304L. 1. Introduction If a certain threshold plastic strain is achieved in a metallic material, defects like voids and micro-cracks start to nucleate. When further strain is applied they grow up to a point where they interact with each other, leading eventually to a macroscopic crack and fracture. The experimental measurement of this damage is not trivial, and di ff erent techniques have been proposed over the years with the aim of characterising ductile damage accumulation. This research is focused on the ductile damage evolution when tensile strain is progressively applied. The diverse techniques for its measurement are reviewed and some of them are tested on hourglass-shaped samples of stainless steel 304L. A methodology to characterise damage is proposed and the results obtained so far are presented. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Experimental techniques for ductile damage characterisation A. Sancho a, ∗ , M.J. Cox a,b , T. Cartwright b , G.D. Aldrich-Smith b , P.A. Hooper a , C.M. Davies a , J.P. Dear a a I perial College London, Department of Mechanical Engineering, London, SW7 2AZ, United Ki gdom b AWE Plc., Materials Science, Aldermaston, Reading, RG7 4PR, United Kingdom Abstract Ductile damage in metallic materials is caused by the nucleation, growth and coalesce of voids and micro-cracks in the metal ma trix when it is subjected to plastic strain. A considerable number of models have been proposed to represent ductile failure focusing on the ultimate failure conditions; however, only some of them study in detail the whole damage accumulation process. The aim of this work is to r view xperimental tech iqu s developed by va us auth rs to measur the accumulati n of ductile damage under tensile loads. The measurement met ods reviewed include: sti ff ness degradation, in entatio , microstructure analysis, ultrasonic waves propagation, X-ray tomography and electrical potential drop. Sti ff ness degradation and i dentation techniques ave been tested on stainless steel 304L hourglass-shaped samples. A special interest is placed in the Continuum Damage Mechanics ap proach (CDM) as its equations incorporate macroscopic parameters that can represent directly the damage accumulation measured in the experiments. The other main objective lies in identifying the strengths and weaknesses of each technique for the assessment of materials subjected to di ff erent strain-rate and temperature conditions. c 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: Ductile damage; Voids; CDM; Continuum Da age Mechanics; High strain-rate; Elastic modulus; I dentation; Ultrasonic waves; X-ray tomography; Electrical potential drop; DIC; Digital Image Correlation, St inless steel 304L. 1. Introductio If a certain threshold plastic strain is achieved in a metallic material, d fects lik voids and micr -cracks start to nucleate. When further strain is applied they grow up to a point wher they interact with ach her, leadi g eventually to a macroscopic crack and fracture. The experimental measurem nt of this damage is not trivial, and di ff erent tec n ques have been proposed over the years with the aim of characterisin ductil damag accumulation. This res arch is focused on the ductile damage ev luti n when tensile strain is progressively applied. The d ver e techniques for its measurement are reviewed and some of them are test d on hourglass-sh ped samples of stainless steel 304L. A methodology to characterise damage is proposed and the results obtained so far are presented. Copyright © 2016 The Aut ors. Published by Elsevier B.V. This s an op n access article under the CC BY-NC-ND licens (http:// ativecommons.org/licenses/by-nc- d/4.0/). P -review under responsibility of the Scientific Co mittee of ECF21. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. 1. Introduction Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation.