PSI - Issue 2_A

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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. 21 st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Applications f Residual Stress in Combatting Fatigue an Fracture M N James a, b *, D G Hattingh b , D Asquith c , M Newby d and P Dou ell d a Marine Science & Engineering, University of Plymouth, Plymouth, ENGLAND b Mechanical Engineering, Nelson Mandela Metropolitan University, Port Elizabeth, SOUTH AFRICA c Engineering and Mathematics, Sheffield Hallam University, Sheffield, ENGLAND d Eskom Holdings SOC Ltd, Rosherville, Johannesburg, SOUTH AFRICA Abstract Residual stresses hav a significant impact on the propensity for engineering components and structure to undergo fatigue and fracture, with either a positive (life enhancing) or negative (life reducing) effect that is largely dependent on the sign of the residual stress relative to that of the applied stress, i.e. on whether they add to, or subtract from, the applied stresses. Accurate life prediction relies on accurate experimental assessment of residual stresses, often combined with simulation using advanced numerical analysis techniques, that must be calibrated against real service data and this implies a necessity for ongoing condition monitoring. The present paper will outline some industrial applications where detailed knowledge of residual stress is advantageous in assessing their influence on fatigue and fracture performance, and hence assists in combatting failure. It will also draw attention to some examples of failures of expensive structures where residual stresses played a role and consider the design and/or fabrication measures that would have led to an amelioration of the level of residual stress and hence prolonged life. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: residual stresses; steam turbine blade and disc; friction taper hydro-pillar processing; weld repair; cracking 1. Introduction As noted in a number of recent papers, e.g. Withers (2007), James et al. (2007), James (2001), residual stresses have a significant impact on the propensity for engineering components and structures to undergo fatigue and fracture, with either a positive (life enhancing) or negative (life reducing) effect that is largely dependent on the sign of the residual stress relative to that of the applied stress, i.e. on whether they add to, or subtract from, the applied 21 st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Applications of Residual Stress in Combatting Fatigue and Fracture M N James a, b *, D G Hattingh b , D Asquith c , M Newby d and P Doubell d a Marine Science & Engineering, University of Plymouth, Plymouth, ENGLAND b Mechanical Engineering, Nelson Mandela Metropolitan University, Port Elizabeth, SOUTH AFRICA c Engineering and Mathematics, Sheffield Hallam University, Sheffield, ENGLAND d Eskom Holdings SOC Ltd, Rosherville, Johannesburg, SOUTH AFRICA Abstract Residual stresses have a significant impact on the propensity for engineering components and structures to undergo fatigue and fracture, with ither a p sitive (life enha ci g) or negative (life redu ing) effect that is largely dependent on the sign of the resid al stress relative to that of th applied stress, i. . on wheth r they add to, or sub ract f om, th applied stress s. Accurat life prediction ies on accurate experim ntal a essme t of residual stresses, ften combined with simulation u ing advanced nume ical analysis techniques, hat must b c librated against al service data and this i plies a nece sity for ongo condition monitoring. The present paper will outline some industrial applications where detailed knowledge f residual stress is advantageous in assessing their influence on fatigue and fracture erforma ce, and hence assists in combatting failure. It will lso dr w attention to some xamp es of failures of expensive structures where residual stresses played a role and consider the design nd/or fabrication asures that would have led to an amelioration of the level of residual stress and hence prol ged life. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: residual stresses; steam turbine blade and disc; friction taper hydro-pillar processing; weld repair; cracking 1. Introduction As noted in a number of recent papers, e.g. Withers (2007), James et al. (2007), James (2001), residual stresses have a signific nt i pact on the ropensity for engineering compon nts and structur to unde go fatigue and fr cture, with either a ositive (life enhancing) r n gativ (life reduci g) effect that is la gely dependent on th sign of the residual str ss relative to that of the applied stress, i.e. on whether th y add to, o subtract from, the appl ed Copyright © 2016 The Authors. Published by Elsevier B.V. This is an open access rticl under the CC BY-NC-ND license (http://creativecommons. rg/lice ses/by-nc- /4.0/). Peer-review under responsibility of the Scientific Committee of ECF21. © 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.

* Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. * Corresponding author. Tel.: +44-1752-586-021; fax: +44-1752-586-103. E-mail address: mjames@plymouth.ac.uk 2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. * Corresponding author. Tel.: +44-1752-586-021; fax: +44-1752-586-103. E-mail address: mjames@plymouth.ac.uk

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.2016.06.003