PSI - Issue 14

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com ienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structu al Integrity 14 (2019) 529–536 Available online at www.sciencedirect.com ScienceDirect StructuralIntegrity 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 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 Determination of J -initiation toughness using pre-cracked small punch test specimens Taslim D. Shikalgar a,* , B. K. Dutta a , J. Chattopadhyay a,b a Homi Bhabha National Institute,Anushakti Nagar, Mumbai 400094, India b Reactor Safety Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India Abstract Determination of fracture properties is important to assess the in-service degradation of nuclear structural materials subjected to thermal fluctuations and irradiation and to calculate the residual life of the component. The pre-cracked small punch test is an alternative method for the determination of fracture properties in case of limited availability of materials and is insufficient for conducting conventional standard tests. In this paper, pre-cracked small punch test (denoted as p-SPT) specimens are used to obtain the fracture J -initiation toughness of nuclear structural steel 20MnMoNi55 and T91.The size of the p-SPT specimen is 10 x 10 x 0.5 mm and wire EDM technique is used to generate through thickness crack profile from mid-point of one side to a point just passing the center f the specimen, producing a rack length to specim n width ratio (a/W) as 0.4. The tests are conducted to get load v/s displacem nt data. Elastic-plastic finite eleme t analysis of t p-SPT specimen is ca ried out and numerically obtained load v/s displacement data are compared wit the experi ental results. This analysis also helped to compute J-integral near the crack tip as a function of load. FE analysis is then repeated using the micromechanical Gurson-Tvergaard-Needleman model to know the load at which crack is initiated. J-initiation is then calculated using J-integral v/s load data. Computed J initiation using micromechanical GTN model has good matching with the value quoted in the literature, which shows the viability of the method. The methodology described in this paper has the potential to determine fracture initiation toughness of aged nuclear materials using pre-cracked small punch tests. © 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. slim D. Shikalgar a a a a,b Reac o on . V h pe //cre Selection an © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: fracture properties, pre-cracked small punch test, J-initiation, Gurson-Tvergaard-Needleman Model Keywords: fracture properties, pre-cracked small punch test J u

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

* Corresponding author. Tel.: +912225597548. E-mail address: staslimd@yahoo.com

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.

* 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.2019.05.063