PSI - Issue 5

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at www.sciencedire t.com cienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structu al Integrity 5 (2017) 385–392 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2017) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2017) 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. 2nd International Conference on Structural Integrity, ICSI 2017, 4-7 September 2017, Funchal, Madeira, Portugal Fatigue analysis of notched specimens made of direct-quenched ultra-high-strength steel under constant amplitude loading M. Dabiri *, T. Björk Laboratory of Steel Structures, Lappeenranta University of Technology, Lappeenranta, Finland Not hed specimens made of a direct-quenched ultra-high-strength steel were investigated by applying the different methods available for the stress- strain analysis of notched components. The methods included the linear rule, Neuber’s rule and the strain energy density method. The latter two methods were used in modified forms to improve their estimation capabilities under plane strain conditions. Meanwhile, an elastic-plastic finite element model equipped with the stabilized cyclic stress-strain curve as the material response was used to capture the strain values at the notch root required for the life estimation. The most advanced method based on the theory of critical distances, abbreviated as TCD, was utilized as well. This method, using the results of the elastic plastic finite lement model, was able to de ine a material characteristic length, which is a material constant, regardless of the no ch configurations or the number of cycles in a low-cycle regime. The results howed that the finit element a alysis and TCD method are able to estimate the lives closest to the experimental values. The TCD method also predicted the lives with the lowest level of unnecessary conservatism, especially in the case of specimens with sharper notches. © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017. Keywords: Low cycle fatigue; notch analysis; critical distance; plane stress/strain; finite element 2nd International Conference on Structur l Integrity, ICSI 2017, 4-7 September 2017, Funchal, Madeira, Portugal Fatigue analysis of notched specimens made of direct-quen hed ultra-high-strength steel under constant amplitude loading M. Dabiri *, T. Björk Laboratory of Steel Structures, Lappeenranta University of Technology, Lappeenranta, Finland Abstract Notched specimens made of a direct-quen ultra-high- trength steel were inves igated by applying the different methods available for the stress- strain nalysis of notched components. The methods included th linear rule, Neuber’s rule and the str in energy density method. T e latter two methods wer us d i modified forms to improve their estimation capabilities und r plan strain conditi . Meanwhile, an elastic-plastic finit elem nt model equipped with the stabil zed cyclic stress-strain urve as the mat rial response was used to capture the strain lues t the notch root required for the life es imation. The most advanced method based on the the ry of critical istances, abbreviat d as TCD, was utilized as ell. This method, using the results of the las - plastic finite element model, was abl to define a mate ial charact risti lengt , which is a materia cons ant, regardless of the notch configurations or he number of cycles in a low-cycle regime. The r sults showed that the finit element analysis and TCD metho are able to estimate the lives closest to the xperimental values. T e TCD method also predicted the lives with the lowest level of unnecessary conservatism, especially in the case of specimens with sharper notches. © 2017 The Autho s. Publ shed by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017. Keywords: Low cycle fatigue; notch analysis; critical distance; plane stress/strain; finite element © 2017 The Authors. Published by Elsevi r B.V. Peer-review under responsibility f the Scientific Committee of ICSI 2017 Abstract

© 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.: +358-46-5266709 E-mail address: mohammad.dabiri@lut.fi * Correspon ing author. Tel.: +358-46-5266709 E-mail address: mohammad.dabiri@lut.fi

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. 2452-3216  2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017 10.1016/j.prostr.2017.07.186 * Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452 3216 © 2017 Th Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017. 2452-3216 © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017.