PSI - Issue 13

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at www.sciencedire t.com cienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structu al Integrity 13 (2018) 379–384 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000 – 000 Available online at www.sciencedirect.com ScienceDirect 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 effects on Structural Integrity Cracking in paintings due to relative humidity cycles Joseph D. Wood a , Cécilia Gauvin b , Christina R.T. Young b , Ambrose C. Taylor a , Daniel S. Balint a , Mari N. C aralambides a* a Department of Mechanical Engineering, Imperial College London, London, SW7 2AZ, UK b School of Culture & Creative Arts, University of Glasgow, Glasgow, G12 8QQ, UK Abstract A numerical study is performed using the finite element method to consider the effects of low-cycle fatigue, specifically induced through relative humidity cycles on paintings. It has been identified that there are two major crack types in paintings, these bei (i) an in erfacial crack (delamination) between paint and support and (i ) a through-thickness (channel) crack in the paint layer itself, arresting on the interface. Therefore a 2D plane strain model for each type of crack has been created, which both consist of an alkyd paint modelled using a visco hyperelastic material model and a primed canvas which is assumed to behave in a linear elastic manner. To account for fatigue damage in both models, cohesive elements located along the interface or through the film thickness respectively, are used and the traction-separation law has been modified to incorporate a fatigue damage parameter. It is possible to expose the models to the same relative humidity cycles, which would typically be seen in museums, enabling the prediction of tim to first crack a d which crack type is more readily grown in the painting. © 2018 The Authors. Published by Elsevier B.V. Peer-review und r responsibility of the ECF22 organizers. Keywords: finite element; interface fracture; irr ver ible cohesive z n s; low-cycle fatigue; thin films; through-thickness crack; viscoela tic. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. ECF22 - Loading and Environmental effects on Structural Integrity Cracking in paintings due to relative humidity cycles Joseph D. Wood a , Cécilia Gauvin b , Christina R.T. Young b , Ambrose C. Taylor a , Daniel S. Balint a , Maria N. Charalambides a* a Department of Mechanical Engineering, Imperial College London, London, SW7 2AZ, UK b School of Culture & Creative Arts, University of G asgow, Glasg w, G12 8QQ, UK Abstract A numerical study is performed using the finite element method to consider the effects of low-cycle fatigue, specifically ind ced through relative humidity cycl s on paintings. It has been identified that there are two major cra k types i paintings, these being (i) an interfacial crack (delamination) betw en paint nd support and (ii) a through-thick ess (channel) crack in the paint layer itself, arresting on the interface. Therefore a 2D pl e strain model for each type of crack has been created, which both consist of an alkyd paint modelled using a visco hyperelastic material model and a primed anvas which is assumed to behave in a linear elastic manner. To account for fatigue damage in both models, cohesive elements located along t e interface or through the film thi kness respectively, re used and the traction-separation law has been modified to incorporate a fatigue damage parameter. It is possible to expose the models t th s m relative humidity cycles, which would typically be seen in museums, enabling the prediction of time to first crack and w i h crack type is more readily grown in th painting. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: finite element; interface fracture; irreversible c hesive zones; low-cycle fatigue; thin films; through-thick ess crack; viscoelastic. Easel paintings are complex composite materials that are usually constructed from a multitude of hygroscopic heterogeneous layers which show a differing dimensional response to changes in the surrounding envir nment (temperature and relative humidity). Two common supports/substrates used for easel paintings are canvas and wood. © 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. Easel paintings are complex composite materials that are usually constructed from a multitude of hygroscopic heterogeneous layers which show a differing dimensional response to changes in the surrounding environment (temperature and relative humidity). Two common supports/substrates used for easel paintings are canvas and wood. 1. Introduction 1. Introduction

* Corresponding author. Tel.: +44 (0)20 7594 7246. E-mail address: m.charalambides@imperial.ac.uk * Corresponding author. Tel.: +44 (0)20 7594 7246. E-mail ad ress: m.charalambides@imperial.ac.uk

* 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 o ganizers.

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.2018.12.063