PSI - Issue 13

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com ienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structural Integrity 13 (2018) 21 9–2113 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. ECF22 - Loading and Environmental effects on Structural Integrity Comparison of SIF solutions obtained by XFEM and conventional FEM for cracks in complex geometries like valve body Ivica Galić a * , Ivan Čular a , Krešimir Vučković a , Zdenko Tonković a a University of Zagreb, Faculty of Mechanical Engineering and Naval Architecture, Ivana Lučića 5, Zagreb 10000,Croatia Globe valve is a type of industrial valve used to obstruct or regulate flow of the fluid in pipelines via linear motion of the plug. The main component of the valve, the valve body, is the carrier of the internal and often variable pressure. The body itself is usually made by sand casting which may result in impurities and metallurgic or shrinkage defects. The above-mentioned, coupled with the relatively geometrically complex shape of the valve bodies, makes the acc r te determination of the crack formation and growth often challenging. Additionally, formation of the cracks in a pressure vessel such as globe valves usually leads to one of the two outcomes. If the crack reaches its critical size under specified loading conditions, a catastrophic failure may occur. On the other hand, the preferred option of stable crack growth can lead to the effect known as leak-before-break. Therefore, it is necessary to accurately determine stress intensity factors (SIF) for cracks in such geometry. This determination is usually made by classical finite element method, and it is very hard to do on complex shape. In addition, it is possible to determine SIF using eXtended Finite Element Method (X-FEM) which is proved on simple geometry. In this paper, the verification of the X-FEM has been conducted by comparison of results obtained by this method and by the classical method on valve body. Presented computational model suggest the possibility of accurately determining fracture mechanics parameters for cracks in geometrically complex components such as those of valve bodies. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: Pressure valve; X-FEM; FEM; stress intensity factor; leak-before-break 1. Introductio Ext nde fin te el ment method is a relatively new method with the poss bility of involving an extra degree of freedom in the area surrounding the crack. Moes et al. (1999) upgraded the method with introduction of the generalized © 2018 The Aut ors. Published by Elsevier B.V. Peer-review und r responsibility of the ECF22 organizers. ECF22 - Loading and Environmental effects on Structural Integrity Comparison of SIF solutions obtained by XFEM and conventional FEM for cracks in complex geometries like valve body Ivica Galić a * , Ivan Čular a , Krešimir Vučković a , Zdenko Tonković a a University of Zagreb, Faculty of Mechanical Engineering and Naval Architecture, Ivana Lučića 5, Zagreb 10000,Croatia Abstract Globe valve is a type of industrial valve used to obstruct or regulate flow of the fluid in pipelines via linear motion of the plug. The main component of the valve, the valve body, is the carrier of the internal and often variable pressure. The body itself is usually made by sand casting which may r sult in impurities and metallurgic or shrink ge defects. The above-mentioned, coupled with the relatively geom trically complex shape of the valve bodies, makes th accurate determination of the crack f rmation and growth often challenging. Additionally, formation of the cracks in a pressure vessel such as globe valves usually leads to one of the two outcomes. If the crack reaches its critical size u der spe ified loading conditions, a catastrophic failure may occur. On the other hand, the preferred option of stable crack growth can lead to the ffect k own as leak-before-break. Therefore, it is necessary to accurately det rmine stress intensity factors (SIF) for cracks in such geometry. This d termination is usually made by classical finite element method, a d it is very hard to do on complex shape. In addition, it is possible to determi e SIF using eXtended Finite Element Method (X-FEM) which is proved on simple geometry. In this paper, the verification of the X-FEM has been conducted by comparison of results obtained by this metho and by the classical method on valve body. Present d computational model suggest the possibility of accurately determining fracture mec anics parameters for cracks in geometrically complex components such as those of valve bodies. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: Pressure valve; X-FEM; FEM; stress intensity factor; leak-before-break 1. Introduction Extended finite element method is a relatively new method with the possibility of involving an extra degree of freedom in the area surroundi g the crack. Moes et al. (1999) upgraded the method with introduction of the generalized © 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. Abstract

* 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.: +385 1 61 68 230; fax: +385 1 61 68 284. E-mail address: ivica.galic@fsb.hr * Corresponding author. Tel.: +385 1 61 68 230; fax: +385 1 61 68 284. E-mail ad ress: ivica.galic@fsb.hr

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.2018.12.200