PSI - Issue 13

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com ienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structural Integrity 13 (2018) 1267–1272 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 Residual stress estimation based on 3D DIC displacement filed measurement around drilled holes Tomasz Brynk a *, Barbara Romelczyk- Baishya a a Warsaw University of Technology, Faculty of Materials Science and Engineering, Woloska 141 str. 02-507 Warsaw, POLAND Residual stress might influence noticeably fatigue strength and fracture behavior of materials, therefore accurate methods of its determination are desired. The most popular method up today is based on strain measurements resulted from material relaxation near the drilled hole. Tensometric rosettes of defined geometry are used for strain measurements in 3 or 6 positions around the hole. The method has some drawbacks related to its sensitivity to hole and rosette centers eccentricity, averaging strain from tensometers area, time consuming rosettes fixing procedures and calculations based on only a few strain readings. Tensometric rosettes might be replaced by non-contact optical displacement fields measurements by means of Digital Image Correlation (DIC) giving much more information (hundreds or thousands of data points) for residual stress calculations. In the paper results of experimen s concerning 3D DIC measurements usage for displacem nt field determination near the drilled hole in preloaded steel sam les whic afterwards were sed as input data in the iterative procedure for the analytical model param ters fitting are presente . Details of testing stand allowing precise hole drilling without need of cameras used for DIC measurements movement during the drilling process and algorithm for inverse method calculations are described. Additionally, FEM model developed for introducing correction terms for blind hole case to the analytical model existing only for through hole instance is discussed. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: residual stress; Digital Image Corrleation (DIC); inverse method © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibil ty of the ECF22 organizer . ECF22 - Loading and Environmental effects on Structural Integrity Residual stress estimation based on 3D DIC displacement filed measurement around drilled holes Tomasz Brynk a *, Barbara Romelczyk- Baishya a a Warsaw University of Technology, Faculty of Materials Science and Engineering, Woloska 141 str. 02-507 Warsaw, POLAND Abstract Residual stress might influence noticeably fatigue strength and fracture behavior of materials, therefore accurate methods of its d termination are desired. The most popular method up tod y is based on strain measurements resulted from material relaxation n ar the drilled hol . T nsometric rosettes of d fined geometry are used for strain measur ments in 3 or 6 positions around the hole. The method has some drawbacks relate to its s nsitivity to hole and rosette centers ccentricity, averag ng st ain from tensomet rs area, time c nsuming rosettes fixing procedures and calculations based on only a few strain readings. Tensometric rosettes might be replaced by no -contact optical displacem nt fields me surements by means of Digi al Image Correlation (DIC) giving muc more information (hundreds or thousands of data points) fo residual stress calculations. In the paper results of experiments conc rning 3D DIC measurements usage for displaceme field d termination ne r the drilled hole in preloaded steel samples which afte wards were used input data in the iterative proc dure for th analytical model param ters fitting are presen d. Detai s of testing stand allowing precise hole drilling without need of cameras used for DIC measurements movement during the drilling process and algorithm for inverse m thod calculati ns ar described. Additionally, FEM model developed for introducing correction terms for blind hole case to the analytical model existing only for through hole instance is discussed. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: residual stress; Digital Image Corrleation (DIC); inverse method Abstract

© 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. 1. Introductio

1. Introduction

Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation. The knowledge of residual stress distribution is crucial in numerous ind strial and scientific areas including fracture mechanics. The most widespread semi-destructive methods for r siduals stress determination are based on calculation of residual stress c mpon nts based on ispla ement or strain measurements near the drilled hol s. The paper presents exp rimental pro edure and testing set-up devot d t residual stress determination by a blind hole drilling and 3D Digital Image C rrelation (3D DIC) displacement field measurements. The knowledge of residual stress distribution is crucial in numerous industrial and scientific areas including fracture mechanics. The most widespread semi-destructive methods for residuals stress determination are based on calculation of residual stress components based on displacement or strain measurements near the drilled holes. The paper presents experimental procedure and testing set-up devoted to residual stress determination by a blind hole drilling and 3D Digital Image Correlation (3D DIC) displacement field measurements.

* 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.2018.12.259