PSI - Issue 13

ScienceDirect Available online at www.sciencedirect.com Available online at ww.sciencedire t.com ScienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structural Integrity 13 (2018) 1232–1237 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural I t grity 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 Methods for Complex Cracked Body Finite Element Assessments Moritz Lessmann a *, John Sawyer a , David Knowles a,b a Atkins, The Hub, 500 Park Avenue, Aztec West, Almondsbury, Bristol BS32 4RZ, UK b University of Bristol, University Walk, Clifton BS8 1TR, UK Abstract This paper presents approaches developed to allow consistent best practice assessments for complex 2/3D defects in engineering structures subjected to primary loading and secondary thermal stresses. Methods are outlined and discussed with reference to recent two- and three-dimensional cracked body analyses of components which have been undertaken to determine tolerable defect sizes and inform sub-critical crack growth calculations. The analyses considered a range of postulated semi-elliptical, through-wall and fully circumferential defects in pressure systems. M xed element type meshing strategies with tied contact in combination with multiple node transformation techniques around the defect front were employed during mesh generation. This facilitated highly refined meshes along the defect front which were required to accurately model extensive plastic deformation in the region of interest. Displacement driven thermal loads required detailed assessment with multiple elasto-plastic material models, since lower bound properties do not necessarily provide the most conservative results. The elasto-plastic J-Integral analyses were shown to provide significant benefit over application of the more conservative Failure Assessment Diagram (FAD) approach. The undertaken assessments were validated against analytical solutions and historic inspection evidence and showed good agreement. In summary the adopted modelling techniques released conservatisms and permitted detailed assessment of complex geometries and load cases. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: Crack Body Modelling, Crack Meshing, FAD, J-Analysis 1. Introduction Defect tolerance assessments are adopted across a broad range of safety critical industries, from aerospace through to high pressure components in the energy industry. The aim of a defect tolerance assessment is to demonstrate integrity of a compon nt which is known to contain a defect, or to assess the structural integrity of a component which is postulated to contain defects at present or in the future. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. ECF22 - Loading and Environmental effects on Structural Integrity Methods for Complex Cracked Body Finite Element Assessments Moritz Lessmann a *, John Sawyer a , David Knowles a,b a Atkins, The Hub, 500 Park Avenue, Aztec West, Almondsbury, Bristol BS32 4RZ, UK b University of Bristol, Univ rsity Walk, Clifton BS8 1TR, UK Abstract This paper presents approaches developed to allow c nsistent best practice assessments for complex 2/3D defects in engineering structures subjected to rimary loading an secondary thermal str sses. Method are outlined and discussed with reference to r cent two- and three-dimensional cracked body analyses of components which have been undertaken to determine tolerable defect sizes and inf rm sub-critic l crack growth calculatio s. The analyses con idered a range of postul ted semi-elliptical, through-wall and fully circu ferential defects in pressure systems. Mixed element type meshing strategies with tied contact in ombination ith multiple node transformation techniques around the defect front were employ d during m sh generation. This facilitated highly refined meshes along the defect front which were required to a curately model extensive plastic deformation in the region of interest. Displacement driven thermal loads required detailed assessment with multiple elasto-plastic mat rial models, since lower bound properties do not necessarily provide the most conservative results. The elasto-plastic J-Integral analyses were shown to provide sig ificant benefit over application of the mor conservative Failure Assessm nt Diagram (FAD) appro ch. The und rtaken assessments were v lidated against nalytical s lutions and historic inspection evidenc and showed good agreement. In summary the adopted modelling t chniques released conservatisms and permitted detailed assessment of complex geometries and load cases. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: Crack Body Modelling, Crack Meshing, FAD, J-Analysis 1. Introduction Defect tolerance assessments are adopted across a broad range of safety critical industries, from aerospace through to high press re com onents in the en rgy industry. The aim of a defect tolerance assessment is to demonstrate integrity of a component which is known to contain a defect, or to assess the structural integrity of a component which is postulated to contain defects at present or in the future. © 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 © 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 organizers. * Corresponding author. Tel.: +44 (0) 1454 662 077. E-mail address: Moritz.lessmann@atkinsglobal.com * Corresponding author. Tel.: +44 (0) 1454 662 077. E-mail ad ress: Moritz.l ssmann@atkinsglobal.com

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.2018.12.253