PSI - Issue 13

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at www.sciencedire t.com ienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structural Integrity 13 (2018) 1999–2 4 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 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. ECF22 - Loading and Environmental effects on Structural Integrity Viscoelastic Behaviour of Self-reinforced Polypropylene Composites under Bending Loads P.N.B. Reis a *, L. Gorbatikh b , J. Ivens b , S.V. Lomov b a C-MAST, Dep. of Electromechanical Engineering, University of Beira Interior, Covilhã, Portugal b Department of Materials Engineering, KU Leuven, Kasteelpark Arenberg 44, Belgium The viscoelastic behaviour of self-reinforced polypropylene (SRPP) was investigated under bending loads. For this purpose, an overfed Twill 2/2 weave pattern was used, which in the hot compacted form is known under the trade name of Curv ® . The areal density of the SRPP fabric is 130 g/cm 3 and the density of this grade polypropylene is 0.92 g/cm 3 . Three point bending (3PB) static tests were performed with a span length of 20 mm, according to the EN ISO 178:2003 recommendations. The strain rate effect on he flexural properties were obtained by the 3PB static tests carried out at room temperature with a displacement rate of 200, 20, 2, 0.2 and 0.02 mm/min. Finally, tests of stress relaxation were also performed, where a fixed strain was applied and the stress was recorded during the load ng tim . It was possible to conclude tha higher train rat s promote higher maximum bending stresses and bending modulus. For both cases, a linear model fits successfully the ata and th strain-rate eff ct on the bending strai at a maximum bending stress showed that SRPP composites are strain r te sensitive. The stress relaxation tests evidence a decrease of the stress with time, and this tendency further persists with the increase of the strain values. Maxwell and Kohlrausch-Williams-Watts (KWW) equations were used to fit the data obtained from the stress relaxation tests and, while the Maxwell model was not good enough to predict the stress relaxation time, the KWW model could fit the data with good accuracy. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. © 2018 Th Authors. Published by Elsevier B.V. Peer-review und r responsibility f the ECF22 organizers. ECF22 - Loading and Environmental effects on Structural Integrity Viscoelastic Behaviour of Self-reinforced Polypropylene Composites under Bending Loads P.N.B. Reis a *, L. Gorbatikh b , J. Ivens b , S.V. Lomov b a C-MAST, Dep. of Electromechanical Engineering, University of Beira Interior, Covilhã, Portugal b Department of Materials Engineering, KU Leuven, Kasteelpark Arenberg 44, Belgium Abstract The viscoelastic behaviour of self-reinforced polypropylene (SRPP) was investigated under bending loads. For this purpose, an ov rfed Twill 2/2 weave pattern was used, which in the hot compacted form is known under the trade n me of Curv ® . The areal density of the SRPP fabric is 130 g/cm 3 and the density f this grade p lypropylene is 0.92 g/cm 3 . Three p int bending (3PB) static tests w re performed with a span length of 20 mm, according to the EN ISO 178:2003 recommendati ns. The strain rate effe ts on the flexural properties were obtained by the 3PB static tests carried out at room temperature with displacement rate of 200, 20, 2, 0.2 and 0.02 mm/min. Finally, tests of str ss relaxation were also performed, where a fixed strain was ppli d and the stress was recorded during the loading time. It was possible to conclude that higher strain rates promote higher maximum bending stresses and bending modulus. For both cases, a li ar model fits successfully the data nd the strain-rate effe t on the i train at a maximum bending stress showed th t SRPP c mposites ar strain rate sensitive. The stress r laxation tests evide ce a decrease of the stress with time, and this tendency further ersists with the incr as of th strain values. Maxwell and Kohlrausch-Williams-Watt (KWW) equatio s were used to fit t e data obtained from th stress relaxation tests and, while the Maxwell model was not good enough to predict the stress relaxation time, the KWW model could fit the d ta wit good accuracy. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Abstract

© 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: Self-reinforced composites; Strain-rate sensitivity; Stress relaxation; Experimental tests. Keywords: Self-reinforced composites; Strain-rate sensitivity; Stress relaxation; Experimental tests.

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

* Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452-3216 © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. 2452-3216 © 2018 The Authors. Published by Elsevier B.V. Peer review under r sponsibility of the ECF22 organizers. * Corresponding author. Tel.: +351 275329948; fax: +351 275240895 E-mail address: preis@ubi.pt * Corresponding author. Tel.: +351 275329948; fax: +351 275240895 E-mail ad ress: preis@ubi.pt

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016.

2452-3216  2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. 10.1016/j.prostr.2018.12.217