PSI - Issue 2_A

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 2 (2016) 277–284 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2016) 000–000 il l li i i

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www.elsevier.com/locate/procedia

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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. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Experimental study of cracks at interfaces with voids Michal K. Budzik a *, Henrik M. Jensen a a Aarhus University, Department of Engineering, Inge Lehmanns Gade 10, Aarhus C, DK Abstract Heterogeneities are inherent parts of adhesively bonded joints. In order to take the full advantage of the adhesive bonding, it is commonly accepted that the bondline and the interface should be homogenous. Flaws and voids present at surfaces of the adherents or trapped inside the bondline are expected to lower the resistance to fracture. Indeed, with a simple inspection of the force vs . displacement curves, as obtained from mode I double cantilever beam experiments for assumed homogenous bond lines, some fluctuations were observed. These fluctuatio are due to the aforeme tione voi s. A set of spec mens were designed with strong/weak adhesion zones perpendicular to the crack propagation direction. Specifically, we address the problem of crack propagation along such interfaces with focus on the relation between the process zone size and the size of the void. In this paper, experimental results are presented followed by a fundamental analytical model. This is sufficient to gain phenomenological insight into the process of crack propagation along adhesively discontinuous interfaces. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: adhesive bonding, crack propagation, heterogenities, interface fracture. 1. Introduction Heterogeneities and adhesive bonding are inherently associated with each other. At the macroscopic joint structure level, bonding is often used to bridge dissimilar (chemically or physically) materials. Once providing kinematic continuity, the stresses inside the materials are necessarily different with steep gradients expected near the interfaces due to mismatch in elastic material parameters as first shown by Dundurs (1969). The adhesive (bondline) itself is also rarely homogenous. It is a common practice that different fillers are used in the constitution of the adhesive to reduce the costs or to increase mechanical or chemical parameters. Also, byproducts could be present in Michal K , , , , e h rs. Published by Elsevier B.V. Peer-review under Keywords: adhesive bonding, crack propagation, heterogenities, interface fractu . e es due to mismatch in e Copyright © 2016 The Authors. Published by Elsevier B.V. This is a open access article under th CC BY-NC-ND license (http:// reativecommons.org/licenses/by-nc-nd/4.0/) Peer-review u der r sponsibility of th Scientific Committee 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.

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* Corresponding author. Tel.: +45 4189 3217. E-mail address: mibu@eng.au.dk . .

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* 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.2016.06.036