PSI - Issue 13

ScienceDirect Available online at www.sciencedirect.com Available online at ww.sciencedire t.com ienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structural Integrity 13 (2018) 1861–1866 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural I t gri y 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 th ECF22 rganizers. ECF22 - Loading and Environmental effects on Structural Integrity Change of Residual Stress due Surface Conditions of Al7075-T6 Marijana Milković a *, Denis Đonlagić b Nenad Gubeljak a , a Faculty of Mechanical Engineering, University of Maribor, Smetanova cesta 17, Maribor 2000, Slovenia b Faculty of Electrical Engineering and Computer Science, University of Maribor, Koroška cesta 46, Maribor 2000, Slovenia Abstract Important goal of Structural Health Monitoring is detection of disintegration process in material in early stage of operation. One possibility is by monitoring the influence of surface degradation process on change of residual stresses during fatigue loading. Results of this investigation are important in analysis of condition and possibility for a Fiber Bragg Grating sensor installation for continuous strain measurements on the surface. The initial condition of the material surface is a consequence of sheet Al7075-T6 plate manufacturing procedure, but during the high cycling fatigue loading, the surface degradation with micro-grain separation occurred. Quantitative measurement of this process consist SEM surface analysis and residual stress measurement in some stage of fatigue loading. It was found the material surface is affected by fatigue loading level and loading ratio. Electropolished and no electropolished surface have been observed and analyzed. Results show that the range of residual stress change is the similar after same number of fatigue cycles. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: fatigue, roughness, residual stress, surface condition, Al7075-T6 1. Introduction The goal of the paper is quantification of surface disintegration of the material Al7075-T6. Papadopolous (1999) mentioned how many ferrous metals posses a fatigue limit proper to the type of loading, which is not the case with aluminum alloys because they do not have the fatigue limit. Papadopolous (1999) also mentioned how some metal grains inside the elementary volume suffer plastic slip under low external cyclic loads . Fatigue has effect on local plastification of some grains in elementary volume which can lead to the change of residual stresses and roughness. ECF22 - Loading and Environmental effects on Structural Integrity Change of Residual Stress due Surface Conditions of Al7075-T6 Marijana Milković a *, Denis Đonlagić b Nenad Gubeljak a , a Faculty of Mechanical Engineering, University of Maribor, Smetanova cesta 17, Maribor 2000, Slovenia b Faculty of Elec rical Engineering and Computer Science, University of Maribor, Koroška cesta 46, Maribor 2000, Slovenia Abstract Important goal of Structural Health Monitoring is detection of disintegration process in material in early stage of operation. One possibility is by monitoring the influence of surfac degradation process o change of residu l str sses during fatigue loading. Results of this investigation are important in analysis of conditi and possibility for a Fiber Bragg Grating se sor installation for continuous strai measurements on the surface. The initial conditio of the material surface is a consequence of sheet Al7075-T6 plate manufacturing procedure, but during the high cycling fatigue loading, the surface degradation w th micro-grain separation occurred. Quantitative measurement of this process onsist SEM surface analysis and residual stress measurement in some stage f fatigue loading. It was found the material surface is affected by fatigu loading level and loading ratio. Electropolished and no electropolished surface have been observed and nalyzed. Results show that the range of residual stress change is the similar after same number of fatigue cycles. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: fatigue, roughness, residual stress, surface condition, Al7075-T6 1. Introduction The goal of the paper is quantification of surface disintegration of the material Al7075-T6. Papadopolous (1999) mentioned how many ferrous metals posses a fatigue limit proper to the type of loading, which is not the case with aluminum alloys because they do not have the fatigue limit. Papadopolous (1999) also mentioned how some metal grains inside the elementary volume suffer plastic slip under low external cyclic loads . Fatigue has effect on local plastification of some grains in ele entary volume which can lead to the change of residual stresses and roughness. © 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 organizers. * Corresponding author. Tel.: +386 (2 )220 7664; fax: +0-000-000-0000 . E-mail address: marijana.milkovic@um.si * Corresponding author. Tel.: +386 (2 )220 7664; fax: +0-000-000-0000 . E-mail ad ress: marijana.milkovic@um.si

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.2018.12.328