PSI - Issue 8

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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 © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of AIAS 2017 International C nference on Stress Analysis AIAS 2017 International Conference on Stress Analysis, AIAS 2017, 6-9 September 2017, Pisa, Italy Analytical Stiffness Matrix for Curved Metal Wires E. Marotta a , P. Salvini a* a Department of Enterprise Engineering, University of Rome "Tor Vergata", via del Politecnico, 1 00133 - Rome - ITALY Abstract The paper presents an analytic stiffness matrix for curved thin metal wires, derived by the application of the second Castigliano’s Theorem. The matrix accounts both bending and axial stiffness contributions in plane. The beam geometry is described by a cubic polynomial function of the curvature radius with a monotonical attitude angle as the independent variable. The solution proposed if fully analytical although a consistent number of adding factors appear. Some test cases are discussed and compared with Finite Element solutions, formed by a plentiful assembly of straight beams. © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of AIAS 2017 International Conference on Stress Analysis. Keywords: Stiffness Matrix; Curved Beam, Metal Wires; Net Structures; Cubic Interpolation 1. Introduction Deployable Space Antennas present some peculiar needs that require clever solutions for the engineers to overcome. First of all weight minimization and packing inside the space rocket before the deployment in the space. Reflectors are as large as 12 m (Thomson, 2000), but much more higher diameters are at present time in the design stage. The mechanism involved in the deployment phase includes the use of very light nets, usually made of molybdenum or tungsten wires, knitted to form the mesh. The knitting procedure is very critical (Marotta et al., 2016) since wires as small as 15 microns are used. It is straightforward to get a mechanical characterization of the net to verify that the AIAS 2017 International Conference on Stress Analysis, AIAS 2017, 6-9 September 2017, Pisa, Italy Analytical Stiffness Matrix for Curved Metal Wires E. Marotta a , P. Salvini a* a Department of Enterprise Engineering, University of Rome "Tor Vergata", via del Politecnico, 1 00133 - Rome - ITALY Abstract The paper presents an analytic stiffness matrix f r curve thin metal wires, derived by the application of the second Castigliano’s Theorem. The matrix accounts both bending and axial stiffness contributions in plan . Th beam geom try is d scrib d by a ub c poly omial functi n of the curvature radius with a monotonical att tude angle as the independent variable. The solution pro os if fully analytical alth gh a consist nt numb r o adding factors appear. So e test cases are discussed and compared with Finite Element solutions, formed by a plentiful assembly of straight beams. © 2017 The Authors. Publ shed by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of AIAS 2017 International Conference on Stress Analysis. Keywords: Stiffness Matrix; Curved Beam, Metal Wires; Net Structures; Cubic Interpolation 1. Intro uction Deployable Space Antennas present some peculiar needs that require clever solutions for the engineers to overcome. First of all weight inimization and packing inside the space rocket befor the d ployment i the space. Reflectors ar as large as 12 m (Thomson, 2000), but much mor higher diameters are at present time in the design stage. The mechanism involved in the deploy ent phase i cludes the use of ver light nets, usually made of molybdenum or tungsten wires, knitted to form the mesh. The knitting procedure is very critical (M r tta et al., 2016) since wires as small as 15 microns are used. It is straightforward to get a mechanical characterization of the net to verify that the © 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.: +39.06.7259.7140; Fax +39.06.7259.7145 E-mail address: salvini@uniroma2.it * Correspon ing author. Tel.: +39.06 7259.7140; Fax +39.06.7259.7145 E-mail address: salvini@uniroma2.it

2452-3216 © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of AIAS 2017 International Conference on Stress Analysis. 2452 3216 © 2017 Th Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of AIAS 2017 International Conference on Stress Analysis.

* 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  2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of AIAS 2017 International Conference on Stress Analysis 10.1016/j.prostr.2017.12.007