PSI - Issue 13

ScienceDirect Available online at www.sciencedirect.com Available online at ww.sciencedire t.com Sci ceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structural Integrity 13 (2018) 1774–1779 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural I t grity 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. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. ECF22 - Loading and Environmental effects on Structural Integrity Stable crack growth in Al-Cu-Mg alloy under various stiffness of loading system in bodies with concentrators Tatyana Tretyakova a *, Mikhail Tretyakov a , Valery Wildemann a a Centre of Experimental Mechanics, Perm National Research Polytechnic University, 29 Komsomolsky AVE, Perm 614990, Russia Abstract In the present work, the influence of the stiffness of the loading system on regularities of inelastic behavior and on processes of the equilibrium crack growth during uniaxial tension in bodies with stress concentrators was studied. Flat specimens (Al-Cu-Mg alloy) with a center notch and initial fatigue crack were extended with a biaxial servo-hydraulic testing system Instron 8850 at room temperature. The mechanical tests were complemented by a digi al image correlation (DIC) and an infrared thermography. By using the 3D DIC-measurement system Vic-3D and the software module ‘virtual extensometer’, it was possible to evaluate the crack opening value, to analyze the evolution of heterogeneous strain fields during the initiation and propagation of cracks. It was revealed that with increasing stiffness of the loading system (by decreasing the gauge length of specimens), the realization of the stable postcritical deformation stage is increasing as well as the inhomogeneity of plastic flow and temperature in the crack tip. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: digital image correlation; ifrared analysis; stress concentrator; crack; stiffness of loading system; failure. 1. Introduction For solving problems of ensuring of structural safety, it is important to obtain and to systematize experimental data on the behavior f materials at the postcritical deformation stage [Vildeman et al (2016)]. It is the stage, when macroscopic fracture c ditions are forming; furthermore, the loading system plays the key role in transition from the stage of equilibrium damage accumulation to non-equilibrium, dynamic stage of fracture and each point on the postcritical deformation stage can correspond to the moment of the loss of load-carrying ability. ECF22 - Loading and Environmental effects on Structural Integrity Stable crack growth in Al-Cu-Mg alloy under various stiffness of loading system in bodies with concentrators Tatyana Tretyakova a *, Mikhail Tretyakov a , Valery Wildemann a a Centre of Experimental Mechanics, Perm National Research Polytechnic University, 29 Komsomolsky AVE, Perm 614990, Russia Abstract In the present work, the influence of the stiffness of the loading system on regularities of inelastic behavior and on processes of the equilibrium crack growth duri g uniaxial tension in bodies with stress co c ntrators was studied. Flat specimens (Al-Cu-Mg alloy) with a center notch and initial fatigue crack were extended with a biaxial servo-hydraulic testing system I stron 8850 at ro m temp rature. The mechanical tests w re compl mented by a digit l image cor elation (DIC) and an infrared thermography. By using the 3D DIC-measurement system Vic-3D and the software module ‘virtual extensometer’, it was possible to evaluate the crack opening value, to analyze the evolution of heterogeneous strain fields during the i itiation and propagation of cracks. It was revealed that with incre sing stiffness f the l ading system (by decreasing the gaug length f specimens), the realiz tion of the stable postcritical deformation stag is increasing as well as the inhomogeneity of plastic flow and temp rature in the crack tip. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: digital image correlation; ifrared analysis; stress concentrator; crack; stiffness of loading system; failure. 1. Introduction For solving problems of ensuring of structural safety, it is important to obtain and to systematize experimental data on the behavior of materials at the postcritical deformation stage [Vildeman et al (2016)]. It is the stage, when macroscopic fracture conditions are forming; furthermore, the loading syste plays the key role in transition from the stage of equilibrium damage accumulation to non-equilibrium, dynamic stage of fracture and each point on the postcritical deformation stage can correspond to the moment of the loss of load-carrying ability. © 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.: +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 o ganizers. * Corresponding author. Tel.: +7-912-499-59-60; fax: +7-342-219-8732. E-mail address: cem.tretyakova@gmail.com * Corresponding author. Tel.: +7-912-499-59-60; fax: +7-342-219-8732. E-mail ad ress: cem.tretyakova@gmail.com

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.2018.12.369