PSI - Issue 5

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 5 (2017) 255–262 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2017) 000 – 000 il l li t . i i t. 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. 2nd International Conference on Structural Integrity, ICSI 2017, 4-7 September 2017, Funchal, Madeira, Portugal Weak and stro g bi-material interfaces and their influence on propagating cracks in plane elastic structures Johannes Scheel a, *, Andreas Ricoeur a a University of Kassel, Institute of Mechanics, Mönchebergstraße 7, D-34125 Kassel, Germany The developing crack paths in heterogeneous structures are the res lt of the inhomogeneous state of stress. The latter stems from e.g. voids or inclusions in an elastic matrix, which are bonded either by strong or weak interfaces. Besides the stiffness of an inclusion, the kind of interface has a decisive influence on the state of stress and therefore on propagating cracks. It is experimentally proven that cracks tend to grow towards regions with lower stiffness (Tilbrook et al., 2006; Judt et al., 2015), therefore matrix cracks might be attracted by interface delamination cracks. In this research the matrix crack growth in bi-material structures is simulated, incorporating dissipative processes arising at weak interfaces and a reference is provided by simulating the crack propagation in the same bi-material but with a strong (perfect) interface. Incremental crack extensions constitute the matrix crack growth, requiring a continuous modification of the geometry. An intelligent re-meshing procedure is applied, where the loading history cannot be neglected due to the presence of dissipative processes (Judt and Ricoeur, 2013b). The crack deflection and crack tip loading are determined by the J-integral criterion and the energy release rate, respectively. The resulting crack paths confirm that the matrix crack tends to grow into the direction of regions with lower stiffness. If weak interfaces are considered, an extremely attracting effect on propagating matrix cracks caused by the delamination is observed, which is stronger than the influence of divergent stiffnesses. © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017. Port g nnes Sch a, a a i it f l, I tit t f i , t , - l, l i t i t t t t lt t i t t t . l tt t . . i i l i i l ti t i , i it t i t . i t ti i l i , t i i t i i i l t t t t t ti . t i i ll t t t t t i it l ti il t l., ; t t l., , t t i i t tt t i t l i ti . t i t t i t i i t i l t t i l t , i ti i i ti i i t i t i i i l ti t ti i t i t i l t it t t i t . t l t i tit t t t i t , i i ti i i ti t t . i t lli t i i li , t l i i t t l t t t i i ti t i , . l ti ti l i t i t i t l it i t l t , ectively. lti t i t t t t i t t i t t i ti ions with lower stiffness. If weak interfaces a i , t l tt ti t ti t i t l i ti i , i i t t t i l of divergent stiffnesse . © 2017 The Authors. Published by Elsevier B.V. i i ilit t i ti i itt . © 2017 The Author . P blished by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017 Abstract

© 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: Crack growth simulation; interface debonding; cohesive zones; J-integral criterion; delamination : r r t i l ti ; i t rf i ; i ; -i t r l rit ri ; l i ti

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

* Corresponding author. Tel.: +49-561-804-2824. E-mail address: j.scheel@uni-kassel.de i t r. l.: - - - . - il : j. l i- l. rr

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. 2452-3216  2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017 10.1016/j.prostr.2017.07.127 * 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 ICSI 2017. l i r . . i i ilit t i ti i itt . - t r . li