PSI - Issue 5

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 Structu al Integrity 5 (2017) 769–776 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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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. Crack path predictions in fiber reinforced composites Paul Judt a *, Jan-Christoph Zarges b , Andreas Ricoeur a , Hans-Peter Heim b a Institute of Mechanics, University of Kassel, Mönchebergstraße 7, 34125 Kassel, Germany a Institute of Material Engineering, University of Kassel, Mönchebergstraße 3, 34125 Kassel, Germany Composite materials exhibit beneficial features compared to conventional engineering material, e.g. a comparable strength and a reduced weight at the same time. To fully exploit these beneficial properties within technical structures, fracture mechanical concepts must be taken into account. The global fracture behavior i mposite materials is related to the local delamination at interfaces between matrix and inclusion as well as the local fracture behaviors of the constituents. Because of their structure, the global elastic and fracture mechanical properties of composites are in general anisotropic. In this work, the directional crack resistance of polypropylene (PP) containing a certain amount of glass fibers (GF) or regenerated cellulose fibers (RCF) is measured. A crack deflection criterion based on the J-integral vector is introduced and implemented into a crack growth model. The J -integral is applied o calculate crack tip loading quantities on a global level, excluding all numerically inaccurate values at the crack tip. With this approach crack paths in anisotropic aluminum alloys have recently been precisely predicted. Crack growth simulations at compact tension (CT)-specimens of PP with GF and RCF are carried out, showing good agreement with the experiments. Several effects resulting from the directional crack resistance are investigated and explained, e.g. a crack deflection at mode-I loaded specimens. © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of he Scientific Committee of ICSI 2017. Keywords: short fiber reinforced c mposites; crack paths; mixed-mode; anisotropy; J-integral 2nd International Conference on Structural Integrity, ICSI 2017, 4-7 September 2017, Funchal, Madeira, Portugal Crack path predictions in fiber reinforced composites Paul Judt a *, Jan-Christoph Zarges b , Andreas Ricoeur a , Hans-Peter Heim b a Institute of Mechanics, University of Kassel, Mönchebergstraße 7, 34125 Kassel, Germany a Institute of Material Engineering, University of Kassel, Mönchebergstraße 3, 34125 Kassel, Germany Abstract Composite materials exhibit beneficial features compared to conventional engineering material, e.g. a comparable strength and a reduced weight at the same time. To fully exploit these beneficial properties within technical structures, fracture mechanical concepts must be take into account. The global fract re behavior in composite materials is related to the local delamination at interfaces between matrix and inclusion as well as the local fracture behaviors of the constituents. Because of their structure, the global elastic and fracture mechanical properties of composites are in general anisotropic. In this work, the directional crack resistance of polypropylene (PP) containing a certain amount of glass fibers (GF) or regenerated cellulose fibers (RCF) is measured. A crack deflection criterion based on the J-integral vector is introduced and implemented into a crack growth model. The J -integral is applied o calculate crack tip loading quantities on a gl bal level, excluding all numerically inaccurate values at the crack p. With this approach crack paths in anisotropic aluminum all ys have recently been precisely predicted. Crack growth simulations at compact tension (CT)-specimens of PP with GF and RCF are carried out, showing good agreement with the experiments. Several effects resulting from the directional crack resistance are investigated and explained, e.g. a crack deflection at mode-I loaded specimens. © 2017 The Au hors. Published by Elsevier B.V. P er-review under esponsibility of th S ie tific Committe o ICSI 2017. © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017 2nd International Conference on Structural Integrity, ICSI 2017, 4-7 September 2017, Funchal, Madeira, Portugal Abstract

© 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: short fiber reinforced composites; crack paths; mixed-mode; anisotropy; J-integral

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

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. 2452-3216  2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017 10.1016/j.prostr.2017.07.168 * Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452-3216 © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017. 2452-3216 © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017. * Corresponding author. Tel.: +49-561-804-2852; fax: +49-451-804-2720. E mail address: judt@uni-kassel.de * Corresponding author. Tel.: +49-561-804-2852; fax: +49-451-804-2720. E-mail address: judt@uni-kassel.de