PSI - Issue 2_B

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 Struc ural Integrity 2 (2016) 187 –1877 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2016) 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. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Micromechanical study and simulation of the interlaminar failure of a woven composite laminate L. Esposito a *, G.P. Pucillo a , F. Penta a , V. Rosiello a a DII, University of Naples “Federico II”, p.le V. Tecchio 80, 80125 Napoli, Italy Abstract The laminate load bearing capability is often compromised by the interlaminar failure even though the integrity of the individual lamina remains intact. The out-of-plane components of the stress tensor, defined at the interfaces between plies, are typically responsible for the delamination of multi-layered materials. Failure models for delamination usually make use of both shear and normal interlaminar stresses but their reliable calculation by finite element analysis requires cautions and special techniques. This is particularly true for woven composites in which the fabric architecture may generate unexpected local normal stresses and consequently influence the fracture occurrence. In this paper a numerical analysis was performed using layered solid elements to predict the global response of the laminate. Then sub-modeling techniques are used with several solid elements through the layer thickness in order to obtain accurate interlaminar stresses in the critical regions. As case study, the short-beam configuration under three-point bending condition was selected. Experimental tests show a reduction of the maximum interlaminar shear stress at failure as effect of the span-depth ratio increase for a given laminate thickness. That evidence, assuming a homogenized material behavior, is unpredicted because the span-depth ratio increase has no significant influence on the interlaminar stresses. The work aims to clarify this not well explained phenomenon with a micromechanics approach. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: Twill fabric; interlaminar stresses; woven delamination; fem sub-modeling 1. Int oductio Laminate behavior has usually been approach d through an understandi g of the behavior of the individual lamina of which it is comprised. At the macroscopic or structural level the laminae are normally modeled through an Copyright © 2016 The Authors. Published by Elsevi r B.V. This is an open access article under the CC BY-NC-ND license (http://cr ativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility f the Scientific Comm ttee of ECF21. © 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.: +39 081 7682463. E-mail address: luca.esposito2@unina.it

* 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 ECF21.

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Copyright © 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ). Peer review under responsibility of the Scientific Committee of ECF21. 10.1016/j.prostr.2016.06.235