PSI - Issue 13

ScienceDirect Available online at www.sciencedirect.com Available online at ww.sciencedire t.com ienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structural Integrity 13 (2018) 12 1–12 8 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural I t gri y 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 Microstructure Analyses and Multiscale Stochastic Modeling of Steel Structures Operated in Extreme Environment Val riy Lepov a, *, Albert Grigoriev a , Mbelle Bisong b,c,d , Valentina Achikasova a , Kyunna Lepova a , Anastasia Ivanova a , Nikolay Balakleiskii e , Boris Loginov e , Artem Loginov f a V.P.Larionov’s Institute of Physical -Technical Problems of the North SB RAS, Yakutsk-677980, Russia, Oktyabrskaja, 1 b University of Dschang, Cameroon, c Ammosov’s North -Eastern Federal University, 58, Belinskogo, 677000, Yakutsk, Russia, d ENSET Douala, Cameroon, e Moscow Institute of Electron Technology (Technical University), Moscow, Russia f M.V.L omonosov’s Moscow State University, Moscow, Russia Abstract The article primarily is concerned with the problem of damage accumulation a d f acture modeling for steel structures operated at low temperature conditions. The inhomogeneity of the weld joints is othe issue associated with the need to examining the microstructure and defects in steel at different scale levels. The next problem is that, extreme environment contains not only the extreme temperature conditions but phase transitions also, fluctuations in temperature, inappropriate in service and repair. Last factors have stochastic behavior and are even uncertain in nature. So these problems are observed and discussed in this paper as theoretical and experimental for building the multiscale model of structural damage accumulation, taking into account the following: the inhomogeneity of the weld, the low temperature brittle-ductile transition for bcc steels, and the uncertainty factors estimation concept. The applications describe the locomotive tire lifetime estimation at low temperature conditions. The modeling approach is based on Kachanov-Rabotnov structural damage accumulation theory and stochastic crack growth modeling. Bayesian probability approach has been used for uncertainty factor estimation. The experimental part includes the internal friction study of low temperature transition mechanism for bcc steel, the mechanical tension and impact toughness tests for locomotive tire steel, and the low-cycling testing and microhardness estimation of mechanical properties for welded steel probes. The experimental testing shows the impact toughness drop at low temperature. The microstructural study for weld joints reveals the small cracks in heat affected zone, so the size and distance between such defects are used for stochastic modeling visualization of crack propagation and crack velocity estimation. The revealing mechanisms and proposed relationships could be used for theoretical and numerical modelling of damage accumulation and fracture in welded steel structures. ECF22 - Loading and Environmental effects on Structural Integrity Microstructure Analyses and Multiscale Stochastic Modeling of Steel Structures Operated in Extreme Environment Valeriy Lepov a, *, Albert Grigoriev a , Mbelle Bisong b,c,d , Valentina Achikasova a , Kyunna Lepova a , Anastasia Ivanova a , Nikolay Balakleiskii e , Boris Loginov e , Artem Loginov f a V.P.Larionov’s Institute of Physical -Technical Problems of the North SB RAS, Yakutsk-677980, Russia, Oktyabrskaja, 1 b University f Dschang, Cameroon, c Ammosov’s No th -Ea tern Fede al University, 58, Belinskogo, 677000, Yakutsk, Russia, d ENSET Dou la , e Mosc w In titute of Electron T chnology (Technical U iversity), Moscow, Ru sia f M.V.L omonosov’s Moscow S ate University, Moscow, Russia Abstract The article primarily is concerned with the problem of damage accum l tion and fracture modeling for steel structures operated at low tempe ature condition . The inhomogeneity of the weld joints is other issue assoc ated with the need to examining the microstructure and defects in steel at different scale levels. The next probl m is that, ex reme environment contains not only the extreme temperature conditio s but phase transi ions also, fluctuations in temperatur , inappropriat in service and repair. Last factors have stochastic behavior and are even uncert in in ature. So these problems are obs rved and discussed in this pap r as theoreti al and experimental for buildi g th multiscal model of structural damage accumulation, taki g into accou t the following: the nhomog neity of the weld, the low temper ture brittle-duc ile transition for bcc steels, nd the uncertainty fa tors estimation co cept. The applications describe the locomotive ire lifetim s imation at low temperature conditions. The modeling approa h is based on Kachanov-Rabotnov structural damag accumulation theory and s ochas ic crack g owth modeling. Bayesian probability approach has been used for uncertainty factor estimation. The exper mental part includes the internal friction study of low tem erature ransiti n mechanism for bcc steel, the mechanical tension and im act toughness tests for locomotive ti e steel, and the lo -cycling testing and microhardness estimation of mechanical properties for welded steel probes. The experimen al testing shows the impact toughnes drop at low temperature. The microstructur l study f r weld j ints reveals the small cracks in heat ff c ed zone, so the size and distance between such defects ar used for s ocha tic m deling visualization of crack propagation and crack v locity estimation. The reveali g m chanisms and proposed relationships could be used for theoretical and numerical modelling of d mag a cumulation a d fractur in weld d steel structures. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: Welded joint; Impact toughness; Microstructure; Microhardness; Ductile-brittle transition; Multiscale modeling Keywords: Welded joint; Impact toughness; Microstructure; Microhardness; Ductile-brittle transition; Multiscale modeling

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 © 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.: +7-411-239-0578; fax: +7-411-239-0599. E-mail address: lepov@iptpn.ysn.ru * Corresponding author. Tel.: +7-411-239-0578; fax: +7-411-239-0599. E-mail ad ress: lep v@iptpn.ysn.ru

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.2018.12.248