PSI - Issue 14

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at www.sciencedire t.com ScienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structural Integrity 14 9 26–33 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. © 2019 Th Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under responsibility of Peer-review under responsibility of the SICE 2018 organizers. 2nd International Conference on Structural Integrity and Exhibition 2018 Damage evolution and fracture in terms of the theory of phase transition L. R. Botvina* A.A. Baikov Institute of metallurgy and material sciences, Russian Academy of Sciences, 49 Leninsky prospect, Moscow 199334, Russia Abstract The development of many fields of science proves the usefulness of the interdisciplinary approach to the phenomena under investigation, based on the physical analogy of the described processes and their general laws. So, it is known the similarity of the relations obtained by J. Gibbs and A. Griffith for the critical size of the solid phase nucleus during crystallization and the critical size of crack at fracture. Both relations were derived from the energy balance condition. Taking into account that the J. Gibbs theory appeared almost a quarter of a century before the theory of A. Griffith, it cannot be ruled out that A. Griffith used the analogy between the critical crack initiation and appearance of critical nucleus of the solid phase. If this is true, then this analogy nd the general thermodynamic approach to the process of fracture were extremely useful and led to the emergence of a new field of science – fracture mechanics. Hence follows the conclusion that the laws of mechanics and physics of fracture can be considered fr m the general positions of the th ory of phase transitions, if we assume that the material is a two-phase one at the stable stage of fracture and co sists of damaged and undamaged volumes. When critical conditions are reached, a " hase transition" occurs with the formation of a new phase: macrocrack. In the paper, this assumption will be confirmed by analyzing the processes of damage accumulation and crack growth under static and cyclic loading and changes in physical properties related with an increase in damage of material. It will also be shown that the known laws of fracture mechanics can be used to describe crystallization processes. © 2018 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under responsibility of Peer-review under responsibility of the SICE 2018 organizers. 2nd International Conference on Structural Integrity and Exhibition 2018 Damage evolution and fracture in terms of the theory of phase transition L. R. Botvina* A.A. Baikov Institute of metallurgy and material sciences, Russian Academy of Sciences, 49 Leninsky prospect, Moscow 199334, Russia Abstract Th development of many fields of science prov s the usefulness of the int rdisciplinary approach to the phenomena under investigation, ased on the physical analogy of the described process s and their general laws. So, it s known the s mil rity of the relat ons obtained by J. Gibbs and A. Griffith for the critical siz of the solid phase nucleus during crystallization and the cr tical size of crack at fracture. Both elations were d riv d from the energy balance condition. Taking into ccount that the J. Gibbs theory app ared almost qu rter of a ce tury before the theory of A. Griffith, it cann t be ruled out that A. Griffith used the analogy betw en the critical cr ck initiation and ap earance of cri ical nucleus of the solid phase. If this is true, then this analogy and the general thermodynamic approa h t the process of fracture wer extremely useful and led to the eme genc of a n w fiel of scienc – fractu e mechanics. H ce foll ws th conclusion that th laws of mechanics a physics f fr cture can be considered from the general p sition the theory of phase transitions, if we ssume that the material is a two-phase one at he table stage of frac ure and consists of damaged and und maged volum s. When critical conditions are reached, a "phase ransition" occurs with the formation of ew phase: macrocrack. In the paper, this assumption will b co firmed by analyzing the processes of damage accumulation nd crack growth under static and cyclic loading and hanges in physical prop rties r lated with an ncrease in damage of material. It will also be shown that the known laws of fracture mechanics can be used to describe crystallization processes. © 2018 The Authors. Published by Elsevier B.V. This is an open access article und r the CC BY-NC-ND lic nse (https://creativecommons.org/licenses/by- c-nd/4.0/) Selection and peer-review under responsibility of Peer-review under responsibility of the SICE 2018 organizers. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: Phase transition; order parameter; fracture kinetic curves; crystallization; radiation damage; ultrasonic attenuation coefficient Keywords: Phase transition; order parameter; fracture kinetic curves; crystallization; radiation damage; ultrasonic attenuation coefficient

Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation.

* Corresponding author. Tel.: +7-499-135-96-83; fax: +7-499-135-86-80. E-mail address: botvina@imet.ac.ru * Correspon ing author. Tel.: +7-499-135-96-83; fax: +7-499-135-86-80. E-mail address: botvina@imet.ac.ru

2452-3216 © 2018 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under responsibility of Peer-review under responsibility of the SICE 2018 organizers. 2452-3216 © 2018 The Authors. Published by Elsevier B.V. This is a open access article und r the CC BY-NC-ND lic nse (https://creat vecommons.org/licenses/by- c-nd/4.0/) Selection and peer-review under responsibility of Peer-review under responsibility of the SICE 2018 organizers.

* 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 PCF 2016. 2452-3216  2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under responsibility of Peer-review under responsibility of the SICE 2018 organizers. 10.1016/j.prostr.2019.05.005