PSI - Issue 2_A

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com cienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Struc ural Integrity 2 (2016) 1763–177 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2016) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2016) 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. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Experimental and numeri al slip line analysis of welded single-edge notched tension specimens Stijn Hertelé a, *, Filip Van Gerven a , Sameera Naib a , N nad Gubeljak b , Wim De Waele a a Ghent University, Soete Laboratory, Technologiepark Zwijnaarde 903, 9052 Zwijnaarde, Belgium b University of Maribor, Laboratory for Machine Parts and Structures, 2000 Maribor, Slovenia Abstract Flaw assessments assume homogeneous material properties, but welds are heterogeneous. A procedure to account for heterogeneity effects on crack driving force (developed at Ghent University and Limerick University) requires strength properties along slip lines originating from the defect tip. For uniaxial tension loading, these lines are assumed straight and oriented 45° to the axis of loading. The presented paper investigates the soundness of this assumption. Clamped single-edge notched tension tests and simulations have been performed on base metal and welded specimens. Extensive deformation analyses reveal the evolution of slip line trajectories as the specimen deforms. Observed slip lines in base metal specim ns are initially close to the assumed 45° trajectories, but deviate towards the notch section as deformation is increased. The change in angle is roughly linear as a function of crack tip opening displacement. Deformation analyses of the welded specimens reveal that hard regions can serve as barriers, causing slip lines to deviate from linearity and split into different branches. The implications of these observations on the flaw assessment of heterogeneous welds are investigated in ongoing work. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: Weld, heterogeneity, slip line analysis, SE(T) specimen 1. Introductio The integrity evaluation of defect d structur s requires a quantification of crack driving force. Most assessment procedures assume the defect to be surrounded by homogeneous material, thus allowing to consult compendia of crack force solutions for simplified configurations. Hereby, a unique weld strength mismatch level is mostly assumed for 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Experimental and numerical slip line analysis of welded single-edge notched tension specimens Stijn Hertelé a, *, Filip Van Gerven a , Sameera Naib a , Nenad Gubeljak b , Wim De Waele a a Ghent University, Soete Laboratory, Technologiepark Zwijnaarde 903, 9052 Zwijnaarde, Belgium b University of Maribor, Laboratory for Machine Parts and Structures, 2000 Maribor, Slovenia Abstract Flaw assessments assume homogeneous material properties, but welds are heterogeneous. A procedure to account for heterogeneity effects on crack driving force (devel ped at Ghent University and Limerick University) requires strength properties along slip lines originati g from the defect tip. For uniaxi l tension loading, these lines are assumed straight and ori ted 45° to the xis of loadi g. The presented pap r investigates the soundne s of this assumptio . Clamped single-edge notched t nsion tests and simul tions have b en performed on base metal and welded specimens. Extensive deformation analyses r veal the evolution of slip li e tr j ctories as the specimen deforms. Observed slip lines in base m tal specimens re initial clos to the assumed 45° trajectories, but deviate towards the otch section as deformation is incre d. The chang in ngle is rou hly line r a function of rack tip op ning displacement. Defo mation analyses of the welded spec mens reveal that hard regions can s rv as barriers, causing sli lin s to deviate from linearity and s lit int dif erent branches. The implications of thes observ tions on the flaw asses ment of heterogeneous welds are investigated in ongoing work. © 2016 The Author . Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: Weld, heterogeneity, slip line analysis, SE(T) specimen 1. Introduction The integrity evaluation of defected structures requires a quantification of crack driving force. Most assessment procedures assum th defect to be su rounded by homogeneous mat ri l, thus allowing to consult compendia of crack for solution for simpli ied configu ations. Hereby, a u iq e weld strength mismatch level is m stly assumed for Copyright © 2016 The Authors. Published by Elsevi r 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 f 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.: +32 (0)93310474; fax: +32 (0)93310490. E-mail address: stijn.hertele@ugent.be 2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. * Corresponding author. Tel.: +32 (0)93310474; fax: +32 (0)93310490. E-mail address: stijn.hertele@ugent.be

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.2016.06.222