PSI - Issue 3

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 Structu al Integrity 3 (2017) 354–361 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. C pyright © 2017 The Auth rs. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://cre tiv commons.org/licenses/by-nc- d/4.0/). Peer-review under responsibility of the Scientific Committee of IGF Ex-Co. XXIV Italian Group of Fracture Conference, 1-3 March 2017, Urbino, Italy A variational model for determining fracture modes in FRCM systems Giovanni Lancioni a *, Jacopo Donnini a , Valeria Corinaldesi a a Università Politecnica delle Marche, Engineering Faculty, Via Brecce Bianche, Ancona 60121, Italy Abstract The bond strength at the yarn to matrix interface is one of the key factor affecting the FRCM mechanical behavior. The interaction between multi-filament yarn and cementitious matrix, governed by complex mechanisms, determines the behavior and failure mode of this composite system. An experimental campaign comprising of 20 pull out tests on multifilament carbon yarns embedded in a cementitious matrix was carried out. Different bond lengths have been analyzed, equal to 20 and 50 mm. Failure modes observed were different depending on the bond length: slippage of the yarn for a bond length of 20 mm and failure of the external filaments when the bond length was increased to 50 mm. The maximum load recorded at fibers breakage was lower than the tensile strength of the yarn, confirm ng th fact that nly the external filaments of the yarn are engaged in the lo d transfer mechanism and the effective ar a is on y a port on of the total area. This work aims to propose a variational model to reproduc th behavior and possible failure mo es of multifilament carbon yarns embedd d in a cementitious matrix. Smeared crack terms are incorporated into the energy functional of the model to account for possible fracture in the yarn and in the matrix, and for debonding at the yarn-matrix interface. The evolution problem is formulated as an incremental energy minimization problem, and discretized by finite ele ents. Numerical simulations are able to accurately describe the composite behaviours and to reproduce experimental results. © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of IGF Ex-Co. i

© 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: FRCM; interface; bond; yarn; variational modelling.

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

* Corresponding author. E-mail address: g.lancioni@univpm.it

* 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 IGF Ex-Co.

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Copyright © 2017 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 IGF Ex-Co. 10.1016/j.prostr.2017.04.031