PSI - Issue 7

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ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com ScienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structu al Integrity 7 (2017) 359–367 Structural Integrity Procedia 00 (2017) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2017) 000–000 ScienceDirect

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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. Copyright © 2017 The Authors. Published y Elsevier B.V. Peer-review under responsibility of he Scientific Committee of the 3rd Internation l Symposium on Fatigu Design and M terial D f cts. 3rd International Symposium on Fatigue Design and Material Defects, FDMD 2017, 19-22 September 2017, Lecco, Italy Study on fatigue crack initiation and propagation from forging defects Igor Varfolomeev a *, Sergii Moroz a , Dieter Siegele a , Kai Kadau b , Christian Amann c a Fraunhofer IWM, Wöhlerstr. 11, 79108 Freiburg, Germany b Siemens Energy, Inc., 5101 Westinghouse Blvd., Charlotte, NC 28273, USA c Siemens AG, Mellinghofer Str. 55, 45473 Mülheim a. d. R., Germany Abstract In this study, crack initiation and propagation under cyclic loading are first experimentally studied by testing specimens fabricated from a rotor material containing manufacturing defects. The latter represent clusters of non-metallic inclusion which size and location are examined by both ultrasonic testing (UT) and fractographic analyses. Three test specimens were extracted from a material block in such a way that the UT indications were located in the middle part of the cross-section. The specimens were then subjected to cyclic loading, applying tensile stresses with different magnitude and stress ratio. This test procedure produced beach marks on specimen fracture surfaces from which the crack initiation and propagation were backtraced. The experimental results suggest that a considerable number of cycles are required for a crack with a size corresponding to the UT indication to be formed. A numerical approach was then adopted for modeling damage accumulation and crack formation starting from a defect cluster. A material model was first calibrated to describe both the cyclic hardening behavior of the defect-free material and strain controlled low cycle fatigue tests. Subsequently, the model was applied to predict the damage evolution and crack formation at a defect group representative of that in one of the specimens studied. © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of the 3rd International Symposium on Fatigue Design and Material Defects. 3rd International Symposium on Fatigue Design and Material Defects, FDMD 2017, 19-22 September 2017, Lecco, Italy Study on fatigue crack initiation and propagation from forging defects Igor Varfolomeev a *, Sergii Moroz a , Dieter Siegele a , Kai Kadau b , Christian Amann c a Fraunhofer IWM, Wöhle str. 11, 79108 Fr burg, Germany b Siemens Energy, Inc., 5101 Westinghouse Blvd., Charlotte, NC 28273, USA c Siemens AG, Mellinghofer Str. 55, 45473 Mülheim a. d. R., Germany Abstract In this study, crack initiation and propag tion under cyclic loading are first experimentally studied by te ting specimens abric ted from a rotor materi l containing manufacturing def cts. The latter r present clusters of non-metallic inclusion which size and location are examined by both ultrasonic te ting (UT) and fractographic nalyses. Three test specimen were extracted fr m a ma erial bloc in such a way that the UT indications ere located in the middle part of the cross-section. The sp cimens wer the subjected to cyclic loading, applying tensile stresses with different magnitude and stress ratio. This test proc dure prod ced beach ma ks on specimen fractur surfaces from which the crack initiation and propag tion were backtra ed. The experimental r s lts suggest that a c nsidera le number of cycles are r quir d for a rack with a size corresp nding to the UT indication to be formed. A numerical approach was then adopted for modeling damage accumulation and crack f rmation starti g from a defect cluster. A material model was first c librated to d scribe both the cyclic hardening behavior of the defect-free material and strain controlled low cycle fatigue tests. Subsequently, the model was applied to predict the damage evolution and crack formation at a defect group representative of that in one of the specimens studied. © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of the 3rd International Symposium on Fatigue Design and Material D fects. Keywords: Forging defects; crack initiation; damage accumulation

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

* Corresponding author. Tel.: +49-761-5142-210; fax: +49-761-5142-401. E-mail address: igor.varfolomeev@iwm.fraunhofer.de

2452-3216 © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of the 3rd International Symposium on Fatigue Design and Material Defects. 2452-3216 © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of the 3rd International Symposium on Fatigue Design and Material Defects. * Corresponding author. Tel.: +49-761-5142-210; fax: +49-761-5142-401. E-mail address: igor.varf lomeev@iwm.fraunhofer.de

* Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt

2452-3216 Copyright  2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of the 3rd International Symposium on Fatigue Design and Material Defects. 10.1016/j.prostr.2017.11.100

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