PSI - Issue 13

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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 Procedia Structu al Integrity 13 (2018) 67 –675 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000–000 Structural Integrity Procedia 00 (2018) 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. ECF22 - Loading and Environmental Effects on Structural Integrity Dynamic fragmentation of ice spheres: Two specific fracture patterns Koji Uenishi a,b , Tomoya Yoshida b *, Ioan R. Ionescu c , Kojiro Suzuki a,b a Department of Advanced Energy, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, 277-8561 Chiba, Japan b Department of Aeronautics and Astronautics, The University of Tokyo, 7-3-1 Hongo, Bunkyo, 113-8656 Tokyo, Japan c Galilee Institute, University Paris 13, 99 Avenue Jean-Baptiste Clément, 93430 Villetaneuse, France Abstract Although ice materials are commonly found not only in our daily life on the earth but also in space, e.g. in the rings of Saturn, their fracture mechanisms, especially those in a dynamic range, have not been fully clarified. In our previous investigation, therefore, collision of a brittle ice sphere (diameter 25, 50 or 60 mm) that is free falling against a fixed plate of ice or polycarbonate has been experimentally observed using high-speed digital video cameras at a frame rate of up to 150,000 frames per second. It has been recognized that there exist basically only two specific fracture patterns generated by this dynamic impact: (i) “Top”-type fracture, normally at a relatively smaller impact speed, where only the bottom surface areas of a sphere are fragmented into small pieces by the impact at bottom and relatively large top-shaped portion is left unbroken; and (ii) “orange segments”-type in which rather flat fracture planes extend approximately along th central axis of the sphere and split th sphere into hree or four larger segments of comparabl size. Prelimi ary comparison of the experimental fi dings with linear elastic wave fields obtained numerically by thre -dimensional finite difference calculati ns suggests two distinct spatiotemporal scales: (1) The “top” fracture pattern is induced by the propagation of surface waves with relatively shorter wavelengths from the bottom along the free surface of the sphere, quickly producing fracture only near the bottom; (2) In the “orange segments ” -type fracture, a longer contact time makes largely stressed regions enlarge more slowly and widely (quasi-statically-like) and larger fracture planes develop along the axis of the sphere. The above speculations seem to be supported by recent computations adopting the Discontinuous Galerkin (DG) method that treat more rigorously the mechanics of dynamic contact between the sphere and plate. ECF22 - Loading and Environmental Effects on Structural Integrity Dynamic fragmentation of ice spheres: Two specific fracture patterns Koji Uenishi a,b , T moya Yoshida b *, Ioan R. Ionescu c , Kojiro Suzuki a,b a Department of Advanced Energy, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, 277-8561 Chiba, Japan b Department of Aeronautics and Astronautics, The University of Tokyo, 7-3-1 Hongo, Bunkyo, 113-8656 Tokyo, Japan c Galilee Institute, University Paris 13, 99 Avenue Jean-B ptiste Clément, 93430 Villetaneuse, France Abstract Although ice materials are commonly found not only in our daily life on the earth but also in space, e.g. in the rings of Saturn, their fracture mechanisms, especially those in a dynamic range, have not been fully clarified. In our previous investigation, therefore, collision of a brittle ice sphere (diameter 25, 50 or 60 mm) that is free falling against a fixed pl te of ice or polycarbonate has been experimentally observed using high-speed digital video cameras a a frame rate of up to 150,000 frames per second. It has been recognized that there exist basically only two specific fracture patterns generated by this dynamic impact: (i) “Top”-type fracture, normally at a relatively smaller impact speed, where only the bottom surface areas of a sphere are fragmented into small pieces by the impact at bottom and a relatively large top-shaped portion is left unbroken; and (ii) “orange segments”-type in which rather flat fracture planes extend approximately along the central axis of the sphere and split the sphere into three or four larger segments of comparable size. Preliminary comparison of the experimental findings with linear elastic wave fields obtained numerically by three-dimensional finite difference calculations suggests two distinct spatiotemporal scales: (1) The “top” fracture pattern is induced by the propagation of surface waves with relatively shorter wavelengths from the bottom along the free surface of the sphere, quickly producing fracture only near the bottom; (2) In the “orange segments ” -type fracture, a longer contact time makes largely stressed regions enlarge more slowly and widely (quasi-statically-like) and larger fracture planes develop along the axis of the sphere. The above speculations seem to be supported by recent computations adopting the Dis ontinuous Galerkin (DG) method that treat more rigorously the mechanics of dynamic contact between the phere and p te. © 2018 The Authors. Published by Elsevi r B.V. Peer-review und r responsibility of the ECF22 organizers.

© 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers.

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

* Corresponding author. Tel.: +81-3-5841-6574; fax: +81-3-5841-6574. E-mail address: yoshida@dyn.t.u-tokyo.ac.jp

* 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. * Corresponding author. Tel.: +81-3-5841-6574; fax: +81-3-5841-6574. E-mail address: yoshida@dyn.t.u-tokyo.ac.jp 2452-3216 © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers.

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.2018.12.111