PSI - Issue 2_B

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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. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Obtaining th J -integ al by diffraction-based crack-fiel strain mapping S.M. Barhli a *, L. Saucedo-Mora b , C. Simpson c,d , T. Becker e , M. Mostafavi f , P.J. Withers c,d , T.J. Marrow a a Department of Materials, University of Oxford, Oxford, OX1 3PH, UK b Institute Eduardo Torroja for Construction Sciences, s/ Serrano Galvache 4, Madrid, 28033, ES c School of Materials, University of Manchester, Manchester, M13 9PL ,UK d Research Complex at Harwell (RCaH), Harwell, Didcot, OX11 0FA ,UK e Department of Mechanical and Mechatronic Engineering, Stellenbosch University, Stellenbosh, 7599, SA f Department of Mechanical Engineering, University of Bristol, Bristol, BS8 1TR, UK Abstract The analysis by diff ction of polycrystalline materials can d termine the full tensor of the elastic strai s within them. P i t-by point m ps of elastic strain can thus be obtain d in fine-grained engineering lloys, typically using synchr tron X-rays or neutrons. In this paper, a novel ap roach is presented to calculate the elastic strain energy releas rate of a loaded crack from two-dimensional strain maps that are obtained by diffraction. The method is based on a Finite Element approach, which uses diffraction data to obtain the parameters required to calculate the J-integral via the contour integral method. The J integral is robust to uncertainties in the crack tip position and to poor definition of the field in the crack vicinity, and does not rely on theoretical assumptions of the field shape. A validation of the technique is presented using a synthetic dataset from a finite element model. Its experimental application is demonstrated in an analysis of a synchrotron X-ray diffraction strain map for a loaded fatigue crack in a bainitic steel. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Obtaining the J -integral by diffraction-based crack-field strain mapping S.M. Barhli a *, L. Saucedo-Mora b , C. Simpson c,d , T. Becker e , M. Mostafavi f , P.J. With rs c,d , T.J. Marrow a a Department of Materials, University of Oxford, Oxford, OX1 3PH, UK b Institute Eduardo Torroja for Construction Sciences, s/ Serrano Galvach 4, Madrid, 28033, ES c Scho l of Materials, University of Manchester, Manchester, M13 9PL ,UK d Research Complex at Harwell (RCaH), Harwell, Didcot, OX1 0FA ,UK e Department of Mechani al and Mechatronic Engineering, Stellenbosch University, Stellenbosh, 7599, SA f Department of Mechanical Engineering, University of Bristol, Bristol, BS8 1TR, UK Abstract The analysis by diffraction of polycrystalline materials can determine the full tensor of the elastic strains within them. Point-by point maps of elastic strain can thu be obtain d in fi e-grained engin ering alloys, typically us g synchrotro X-rays r neutrons. In this pape , a ovel approach is pres nted to calculate the elastic str in energy release rate of a loaded crack from two-dimensional strain maps that are obtain d by diffraction. Th m thod s based o a Finit Element appr ch, which uses diffractio dat to btain the p ram ters required to c lculate the J-in egral via the contour ntegral method. The J integral i robust t uncertainties e crack tip position and to poor definition of the field in the c ack vicinity, an do s not rely on theoretical assumptions of the field sha e. A v lidation of th tech ique is pr sented using a synthetic dataset from a finite el m nt model. Its experimental application is demonstrated in an a alysis of a y chrotro X-ray diffraction strain ap for a loaded fatigu crack in a bainitic steel. © 2016 The Authors. Pu lished by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Copyright © 2016 The Authors. Published by Elsevier B.V. This is an open access ar icle 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. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: J -integral; XRD; diffraction; EDXRD; Stress-Intensity Factor; strain mapping Keywords: J -integral; XRD; diffraction; EDXRD; Stress-Intensity Factor; strain mapping

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

1. Introduction A recurrent fracture mechanics requirement is to quantify the field surrounding a crack that controls its 1. Introduction A recurrent fracture mechanics requirement is to quantify the field surrounding a crack that controls its

* Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review und r responsibility of the Scientific Committee of ECF21. 2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer review under r sponsibility of the Scientific Committee of ECF21.

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.2016.06.315