PSI - Issue 2_B

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com ScienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Struc ural Integrity 2 (2016) 265 –2658 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2016) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2016) 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. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Mathematical and numerical correction of the DIC displacements for determination of stress field along crack front Chernyatin A.S. a *, MatvienkoYu.G. b , Lopez-Crespo P. c a Bauman Moscow state technical university, ul. 2-ya Baumanskaya, 5, Moscow, 105005, Russia b Mechanical engineering research institute of the Russian Academy of scienc s, Maly Kharitoniev kiy pereulok, 4, Moscow, 101990, Russia c University of Malaga, C/Dr Ortiz Ramos, s/n 29071, Malaga, Spain Abstract The digital image correlation method (DIC) has wide application to determine the singular (stress intensity factor) and non singular (T-stress) components of the stress field in the vicinity of the crack-tip. DIC has a simple implementation and provides large arrays of experimental data. However, it requires an a priori or post processed determination of the rigid body shifting and the crack-tip position. A method for mathematical processing of the experimental displacement fields obtained by means of DIC is presenting and validating in this work. The method provides an accurate and direct solution for the problem of simultaneous determination of the body displacement and the position of the crack-tip and crack plane orientation as well as appropriate terms of Williams’s series expansion. It is basin on geometric and kinematic relations and involves a solution of multiparametric minimization. As a result, this procedure allows better accuracy in the estimation of fracture mechanics parameters. An interactive Matlab program with graphical user interface was developed for implementation of the method. The program has a wide functionality for filtration and selection of the experimental data presented in the form of displacement fields as well as for control of the solution and it verification. Possibility of automatic accounting of the real position and orientation of the crack by means of definition of appropriate geometrical parameters, allows simplifying the procedure for measurement of the displacement fields and post processing. The method has a great potential for application to full-scale engineering components and allows automatic tracking of a fatigu crack with simultaneous determination of the fracture mechanics parameters. The efficiency of the approach has been demonstrated on real fatigue crack on compact tension specimens with different crack lengths and loading conditions. It should be noted, that the propos d method can be using as a basis of the determination of the fracture mechanics parameters along the crack front. For this purpose three steps must be performing: 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Mathematical and numerical correction of the DIC displacements for determination of stress field along crack front Chernyatin A.S. a *, MatvienkoYu.G. b , Lopez-Crespo P. c a Bauman Moscow state technical university, ul. 2-ya Baumanskaya, 5, Moscow, 105005, Russia b Mechanical engineering research institute of the Russian Academy of sciences, Maly Kharitonievskiy pereulok, 4, Moscow, 101990, Russia c University of Malaga, C/Dr Ortiz Ramos, s/n 29071, Malaga, Spain Abstract The digital image correlation method (DIC) has wide application to determine the singular (stress intensity factor) and non singular (T-stress) components of the stress field in the vicinity of the crack-tip. DIC has a simple implementation and provides large arrays of experimental data. However, it requires an a priori or post processed determination of the rigid body shifting and the crack-tip position. A method for mathematical processing of the experimental displacement fields obtained by means of DIC is presenting and validating in this work. The method provides an accurate and direct sol tion for the problem of simult eous det m nation of the body disp acement and the position of the crack-tip and crack pla e orientation as well as appropriat t rms of Will ams’s s ries expansion. It is basin on geometric and kinematic relations and involves a s lution of multiparametric minimization. As a result, this proc dure allows better accuracy in the estimation of fracture mechanics arameters. An interactive Matlab program with graphical user interface was developed for implementatio f the method. T program has a wide functionality for filtration and selection of the experimental data presented in the form of displacement fields as well as for control of the solution and it verification. Possibility of automatic accounting of the real position and orientation of the crack by means of definition of appropriate geometrical parameters, allows simplifying the procedure for measurement of the displacement fields and post processing. The method has a great potential for application to full-scale engineering components and allows automatic tracking of a fatigue crack with simultaneous determination of the fracture mechanics parameters. The efficiency of the approach has been demonstrated on real fatigue crack on compact tension specimens with different crack lengths and loading conditions. It should be noted, that the proposed method can be using as a basis of the determination of the fracture mechanics parameters along the crack front. For this purpose three steps must be performing: 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.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. * Corresponding author. Tel.: +7-499-263-6391; fax: +7-499-267-48-44. E-mail address: chernyatin_as@bmstu.ru 2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. * Corresponding author. Tel.: +7-499-263-6391; fax: +7-499-267-48-44. E-mail address: chernyatin_as@bmstu.ru

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.2016.06.331