PSI - Issue 7

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com Sci ceDirect Structural Integrity Procedia 00 (2016) 000 – 000 P o edi Structural Integr ty 7 (2017) 44–49 ScienceDirect Structural Integrity Procedia 00 (2017) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2017) 000–000

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www.elsevier.com/locate/procedia 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. Publis ed by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of the 3rd International Symposium on Fatigue Desig and Material Defects. 3rd International Symposium on Fatigue Design and Material Defects, FDMD 2017, 19-22 September 2017, Lecco, Italy Initiation of fatigue cracks and lifetime of Ni-base superalloys at high mean stress and temperature Ludvík Kunz a * , Vít Horník a , Pavel Hutař a , Stanislava Fintová a a Institute of Physics of Materials, Academy of Sciences f the Czech Republic, Žižkova 22, 616 62 Brno, Czech Republic Abstract The effect of high-frequency cycling (120 Hz) superimposed on high tensile mean stress on a lifetime of cast Ni-base superalloys IN 713LC at 800 °C and MAR-M 247 at 900 °C was investigated. It has been found that both the alloys exhibit qualitatively similar behavior in creep/fatigue loading conditions. Superposition of small stress amplitudes on the tensile mean stress does not influence the time to fracture until the stress amplitude reaches a threshold value, which is dependent on the mean stress. The higher the mean stress the higher is the stress amplitude threshold value. The observed creep/fatigue behavior is governed by two mechanisms: (a) formation and growth of intergranular cracks by creep mechanism (b) initiation and growth of fatigue cracks from the intergranular creep cracks. The casting defects do not play any important role as regards the lifetime under investigated loading conditions. © 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. Keywords: IN 713LC; MAR-M247; creep/fatigue loading; time to fracture; defects 3rd International Symposium on Fatigue Design and Material Defects, FDMD 2017, 19-22 September 2017, Lecco, Italy Initiation of fatigue cracks and lifetime of Ni-base superalloy at high mean stress and temperature Ludvík Kunz a * , Vít Horník a , Pavel Hutař a , Stanislava Fintová a a Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Žižkova 22, 616 62 Brno, Czech Republic Abstract The ffect of h gh-frequency cycl ng (120 Hz) su erimpos d on high tensile mean stress on a lifetim of cas Ni-base up ralloys IN 713LC at 800 °C and MAR-M 247 at 900 °C was inv tigated. It has been found that bo h the alloys exhibit qualitatively simil r behavior in creep/fatigue loading co ditions. Supe position of small stress a plitudes on the tensile mean stress does not influence th time to fracture until the stre s amplitude reaches threshold value, which is depend nt on the m an str ss. The higher the mean stress the higher is the stress amplitude threshold value. The observed creep/fatigue behavior is governed by two mecha isms: (a) formation an growth o intergranular cracks by creep mechanism (b) initiation and growth of fati ue cracks from the intergranular creep cracks. The casting defects do not play any important role as regards the lifetime under investigated loading conditi ns. © 2017 The Authors. Published by Elsevier B.V. P er-review under responsibility of the Scientific Committee of the 3rd International Symposium on Fatigue Design and Material Defects. Keywords: IN 713LC; MAR-M247; creep/fatigue loading; time to fracture; defects

© 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.: +420 604 873 893 E-mail address: kunz@ipm.cz

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.: +420 604 873 893 E mail address: kunz@ipm.cz

* 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 PCF 2016.

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.2017.11.059