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) 1545–1553 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

www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia

www.elsevier.com/locate/procedia

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 The gigacycle fatigue strength of steels: a review of structural and operating factors Thierry Palin-Luc a* Dalenda Jeddi b a Arts et Metiers ParisTech, CNRS, I2M Bordeaux, Esplanade des Arts et Metiers, 33405 Talence Cedex, France b University of Tunis El Manar, Laboratory of Applied mechanics and Engineering, Campus Universitaire El Manar, BP 37, 1002 Tunis, Tunisia. Abstract It is known that usual frequency up to 100 Hz has no influence on the high cycle fatigue (HCF) strength of steels. However, in the very high cycle fatigue (VHCF) regime, the frequency effect is still unclear. Indeed, a high frequency can lead to heating, instability of the microstructure and degradation or improvement of the mechanical properties of the material, which in turn depend on the type of loading and on the operating environment. Based on a large literature review of many experimental data in gigacycle regime, a synthesis is proposed to discuss the effect of the structural and operational factors on the VHCF characteristics of low and high strength steels (Jeddi et al. (2018)). Failure mechanisms in HCF and VHCF (surface or internal crack initiation) are related to S-N curve shape. The effect of the microstructural and mechanical features on the VHCF resistance is debated depending on different paramet rs: microstructur , inclusion size, inclusion type and depth, hydr gen, environment, m x m m tensile strength of the steel and residual stresses. The influence of he l ading conditions on the VHCF strength is addr ssed by taking into account both t e loading frequency effect, the highly stressed volume, the lo ding type and loading ratio. Finally, the influence of the testing techniques (pulse-pause or continuously cyclic loading) is discussed. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 org nizers. ECF22 - Loading and Environmental effects on Structural Integrity The gigacycle fatigue strength of steels: a review of structural and operating factors Thierry Palin-Luc a* Dalenda Jeddi b a Arts et Metiers ParisTech, CNRS, I2M Bordeaux, Esplanade des Arts et Metiers, 33405 Talence Cedex, France b University of Tunis El ana , Laboratory of Applied mechanics and Engin ering, Campus Universitaire El Manar, BP 37, 1002 Tunis, Tunisia. Abstract It is known that usual frequency up to 100 Hz has no influence on the high cycle fatigue (HCF) strength of steels. However, in the very high cycle fatigue (VHCF) regime, the frequency effect is still unclear. Indeed, a high frequency can lead to heating, instability of the microstructure and degradation or improvement of the mechanical properties of the material, which in turn depend on the type of loading and on the operating environment. Based on a large literature review of any experimental data in gigacycle regime, a synthesis is prop sed to discuss the effect of the structural and operational factors on the VHCF characteristics of low and high strength steels (Jed i et al. (2018)). Failure mechanisms i HCF and VHCF (surface or internal crack initiation) are related to S-N curve shape. The effect of the microstructural and mechanical features on the VHCF resistance is debated depending o different parameters: micr stru ture, inclusion size, inclusio type and depth, y rogen, enviro ment, maximum tensile strength of the steel and residual stresses. The influence of the l ading con itions on th VHCF strength is addressed by taking into account both the loading frequency effect, the highly stressed volume, the loading type and loading ratio. Finally, the influence of the testing techniques (pulse-pause or continuously cyclic loading) is discussed. © 2018 The Authors. Published by Elsevier B.V. Peer-review under respons bility of the ECF22 organizers. Keywords: Gigacycle fatigue; Steel; Crack initiation; Micromechanism; Influence factors

© 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: Gigacycle fatigue; Steel; Crack initiation; Micromechanism; Influence factors * Corresponding author. Tel.: +33 556 845 360; fax: +33 556 845 366 E-mail address: thierry.palin-luc@ensam.eu Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation. * Corresponding author. Tel.: +33 556 845 360; fax: +33 556 845 366 E-mail address: thierry.palin-luc@ensam.eu

© 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. © 2018 The Authors. Published by Elsevier B.V. Peer-review under espons bility of the ECF22 organizers.

* Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452-3216 © 2018 The Authors. Published by Elsevier B.V. Peer-review u der 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.

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.2018.12.316