PSI - Issue 2_B

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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. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Nonlinear stress intensity factors in fracture mechanics and their applications V. Shlyannikov a a Kazan Scientific Center of Russian Academy of Sciences, Lobachevsky Street, 2/31, Kazan 420111, Russia Abstract A new parameters for characterization of the crack growth resistance for a power law hardening materials and structures under normal and elevated temperature are introduced in the form of plastic and creep stress intensity factors. A numerical method is proposed for estimating the governing parameter of the elastic-plastic and creep crack tip fields in the form of an I n integral along the through-the-thickness straight and curved crack fronts. Equations are also proposed for calculating the I n -factor at both the deepest point along the crack front and the crack tip on the surface. Static and fatigue crack growth and in-plane and out-of-plane constraint effects are studied through experiments and computations for the material different properties. It is further demonstrated that for moderately large-scale yielding conditions or plastic deformations, the fracture process can be controlled by the single parameter K P based on the elastic-plastic numerical solutions and, therefore, is reflected in the influence of the cracked body geometry and loading conditions. Keeping in mind the purpose of practical application of the introduced nonlinear stress i tensity factors, a engineering approach to the prediction of residual lifetime of cracked steam turbine rotors components which operate at maintenance under cyclic loading conditions is proposed. Using the nonlinear stress intensity factors approximate estimations of carrying capacity are presented for the different stress-strain state of steam turbine disks at the operation. As result it is stated that a one-parameter approach based on the plastic and creep stress intensity factors are more convenient for practical use in assessing the fracture resistance under monotonic and cyclic loading of materials and structural elements with respect to the two parameters fracture theories. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Nonlinear stress intensity factors in fracture mechanics and their applications V. Shlyannikov a a Kazan Scientific Center of Russian Academy of Sciences, Lobachevsky Street, 2/31, Kazan 420111, Russia Abstract A new param ters for charac e iz tion of the crack growth resistance for a pow r law hardeni g material and structures under normal and elevated temperature are i troduced in the form of plastic and cre p stress intensity factors. A numerical method is proposed for es imating the governing parameter of the elastic-plas c and creep c ack tip ields in the form of an I n integral along th hr ugh-the-thickness st aight and curved crack fronts. Equations are also proposed for calculati g the I n -factor at b th the deepest point along the crack front and the crack ip on the s rf ce. Static and fatigue crack growth and in-plane and out- f-pl n cons raint effects are studied through experiments and computations for the mat rial diff rent properties. It is furth r demonstrated that for moderately large-scale y elding o ditions or p astic deformations, the fracture process ca b controlled by th single para eter K P b sed on the ela tic-plastic nu erical sol ti ns and, therefore, is reflected in the influence of the cracked body geometry and loading conditi ns. Keeping in mind the purpose of practical applica ion of the intr duced nonlinear stress intensity f ctors, an engineering approa h to the predict on of residual lifetime of cracked steam turbine rotors component which operat at mai tenance u der cy lic loading con iti ns is proposed. U ing the nonlinear stress int ns ty f ctors a p oximate estimation of carrying capacity ar presented for the differ nt stress-strain state of steam turbine disks at th operation. As result it is tated that a one-parameter approach based on the plastic and creep stress intensity factors a e more conv ient for practical us in assessing the fracture resistance under monotonic and cyclic loading of materials and structural elements with respect to the two parameters fracture theories. © 2016 The Autho s. Publ shed by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Copyright © 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of the Scientific Committee of ECF21. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: Plastic and creep stress intensity factors; in-plane and out-of-plane constraint; structural integrity assessment. Keywords: Plastic and creep stress intensity factors; in-plane and out-of-plane constraint; structural integrity assessment. Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation. 1. Introduction The engineering application of the fracture mechanics of solids to real cracked structures requires an appropriate parameter to quantify the crack tip constraint. Moreover, practical structural components have finite thicknesses, and 1. Introduction Th ngineering appli ation of the fracture mechanics of solid o real cracked structures requires an appropriate parameter to quantify the crack tip constraint. Moreover, practical structural components have finite thicknesses, and

* Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452 3216 © 2016 Th Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. 2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21.

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Copyright © 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ). Peer review under responsibility of the Scientific Committee of ECF21. 10.1016/j.prostr.2016.06.096