PSI - Issue 2_A

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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 Description of short fatigue crack propagation under l w cycle fatigue regime Pavel Hutař a *, Jan Poduška b,c , Alice Chlupová b , Miroslav Šmíd b , Tomáš Kruml b , Luboš Náhlík a a CEITEC IPM, Institute of Physics of Materials, Žižkova 22, 616 62 Brno, Czech Republic b Deparment of Mechanical Properties, Institute of Physics of Materials, Žižkova 22, 616 62 Brno, Czech Republic a Faculty of Mechanical Engineering, Brno University of Technology, Technická 2, 616 69 Brno, Czech Republic Abstract Measurement of the short fatigue crack propagation can come across a lot of difficulties from the experimental point of view and interpretation of the results is also sometimes controversial. For simplicity, usual description of the short cracks is based on linear elastic fracture mechanics (using the concept of stress intensity factor). In this case, significant differences between short cracks and long cracks are usually presented. Most of the discrepancies are simply given by non-validity of the linear elastic fracture mechanics approach. In our case of physically short fatigue cracks the level of applied stress is close to cyclic yield stress of the material and, due to large amount of plasticity, conditions of linear elastic fracture mechanics are not satisfied. As a consequence, non-linear elastic plastic fracture mechanics is used for description of the short crack behavior in this article. Concept based on plastic part of J-integral is proposed for the description of the short crack behavior and data obtained for different strain amplitudes are compared. This concept is validated on experimental data obtained on steel 316L. © 2016 The Authors. Published by Elsevier B.V. Peer-revi w under responsibility of th Scientific Committee of ECF21. Keywo ds: short fatigue cr cks, low cycle fatigue, stic par of J-integral, numeric l modelling 1. Introduction Damage tolerant design has been a highly regarded design philosophy in the last two decades in the area of the fatigue failures (Lawson et al. (1999)). Based on this philosophy, structures are designed to allow limited crack propagation and propagated cracks should be detected early enough to prevent failure of the component. Due to the 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Description of short fatigue crack propagation under low cycle fatigue regime Pavel Hutař a *, Jan Poduška b,c , Alice Chlupová b , Miroslav Šmíd b , Tomáš Kruml b , Luboš Náhlík a a CEITEC IPM, Institute of Physics of Materials, Žižkova 22, 616 62 Brno, Czech Republic b Deparment of Mechanical Properties, Institute of Physics of Materials, Žižkova 22, 616 62 Brno, Czech Republic a Faculty of Mechanical Engineering, Brno Universit of Technology, Technická 2, 616 69 rno, zech epublic Abstract Measurement of the short fatigue crack propagation can come across a lot of difficulties from the experimental point of view and int rpretatio resul s is also sometimes controversial. For simplicity, usual description of th sho t cracks is based on linear elastic fr cture mechanics (using the concept of stress intensity factor). In this cas , s gn ficant differences between short cracks and long racks are usually present d. Most the discr pancies are simply given by on-vali ty of th linear la tic fracture mechanics appro ch. In our case of physically short fatigue cracks the leve of applied stress is close to cyclic yield ress of th aterial and, due to large amount of pla ticity, conditions of linear elastic fracture mechanics are n t satisfied. As a consequence, non-line r elastic plastic fracture mech n s is use f r descr ption of he short crack behavio i this article. Concept based on plastic p t of J-integral is proposed for the de cription of the short crack b havior and data obtained for differ nt strain amplitudes are compared. This concept is vali ated on experime tal data obtained on steel 316L. © 2016 Th Aut ors. Published by Elsevier B.V. Peer-review under espons bility of the Scientific Committee of ECF21. Keywords: sho t fatigue cracks, low cycle fatigue, plastic part of J-integral, numerical modelling 1. Introduction Damage tolerant design has been a highly regarded design philosophy in the last two decades in the area of the fatigue failures (Lawson et l. (1999)). Based on this ph losophy, structures are designed to allow limit d crack propagation and propagat d cracks should be etected early enough to prevent failur of the c mp nent. Due to the 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: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation.

* Corresponding author. Tel.: +420 532290351 E-mail address: hutar@ipm.cz * Corresponding author. Tel.: +420 532290351 E-mail address: hutar@ipm.cz

* Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review un r responsibility of the Scientific Committee of ECF21. 2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer review under r sponsibility 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.2016.06.377