PSI - Issue 13

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at www.sciencedire t.com Sci ceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structural Integrity 13 (2018) 1256–126 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. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. ECF22 - Loading and Environmental effects on Structural Integrity Multiaxial high cycle fatigue criteria applied to motor crankshafts Roberta Amorim Gonçalves a , Marcos V. Pereira a *, Fathi A. Darwish b a Catholic University of Rio de Janeiro, Department of Chemical and Materials Engineering, Rua Marques de São Vicente 225, 22453-901 Rio de Janeiro – RJ, Brazil. b Fluminense Federal University, Department of Civil Engineering, Rua Passo da Patria 156, 24210-240 Niteroi – RJ, Brazil. Abstract A comparative study is made of the applicability of critical plane based multiaxial high cycle fatigue models to predicting the fatigue behavior of metallic materials. A number of models, namely Matake, McDiarmid, Carpinteri and Spagnoli, Liu and Mahadevan and Papadopoulos, were applied to fatigue limit states, involving synchronous fully reversed in-phase sinusoidal bend and torsion loading. The results obtained indicated a good predictive capability of the models with an average error index situated approximately between -5,5% and 4,5%. However, this average was limited to less than 3% for the latter three models. Finally, the critical plane orientation, which, for a given material, is characteristic of the proper model, is compared with that of the fracture plane, exclusively determined by the ratio between the shear stress and normal stress amplitudes. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: fully reversed loading; proportional loading; critical plane; fracture plane; error index. 1. Introduction Fatigue is th most usual mechanical damage in all ngineeri g fields. To prevent such a problem, a projection of the fatigue life incorporating numerical, analytical and experimental tests seem to be necessary. As many mechanical components, such as railroad wheels, crankshafts, axles and turbine blades, are expected to suffer multiaxial loading during service operations, the fatigue problem becomes more complex due to the complexity of the stress states, loading histories and different orientations of the initial crack. Accordingly, the need has been arising to introduce criteria capable of generalizing the fatigue limit concept so as to include multiaxial loading conditions. Such criteria can be divided into three groups: stress based, strain based and energy based models can be divided into three groups: stress based, strain based and energy based models. ECF22 - Loading and Environmental effects on Structural Integrity Multiaxial high cycle fatigue criteria applied to motor crankshafts Roberta Amorim Gonçalves a , Marcos V. Pereira a *, Fathi A. Darwish b a Catholic University of Rio de Janeiro, Department of Chemical and Materials Engineering, Rua Marques de São Vicente 225, 22453-901 Rio de Janeiro – RJ, Brazil. b Fluminense Federal University, Department of Civil Engineering, Ru Passo da Patria 156, 24210-240 Niteroi – RJ, Brazil. Abstract A comparative study is made of the applicability of critical plane based multiaxial high cycle fatigue models to predicting the fatigue beha ior of metallic materials. A number of models, namely Matake, McDiarmid, Carpinteri and Spagnoli, Liu and Mahadevan and Papadopoulos, were applied to fatigue limit states, involving synchronous fully reversed in-phase sinusoidal bend and torsion loading. The results obtained indica ed a good predictive capability of the models with an verage error index situated approximately between -5,5% and 4,5%. However, this aver ge was limited t less than 3% for the latter three models. Fin lly, the critical plane ori ntation, which, for a given material, is characteristic of the proper model, is compared with that of the fractur plane, exclusively determined by the ratio betwe n the shear str ss and normal str ss amplitudes. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: fully reversed loading; proportional loading; critical plane; fracture plane; error index. 1. Introduction Fatigue is the most usual mechanical damage in all engine ring fields. To pr vent such a problem, a projection of the fatigue life incorporating numerical, analytical and experimental tests seem to be necessary. As many mechanical components, such as railroad wheels, crankshafts, axles and turbine blades, are expected to suffer ultiaxial loading during service operations, the fatigue problem becomes more complex due to the complexity of the stress states, loading histories and different orientations of the initial crack. Accordingly, the need has been arising to introduce criteria capable of generalizing the fatigue limit concept so as to include multiaxial loading conditions. Such criteria can be divided into three groups: stress based, strain based and energy based models can be divided into three groups: stress based, strain based and energy based models. © 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. E-mail address: marcospe@puc-rio.br *corresponding author. E-mail address: marcospe@puc-rio.br

* 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.2018.12.257