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 Structu al Integrity 2 (2016) 632–639 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 Safety assessme t of steels under ULCF loading conditions with damage mechanics model Yidu Di a , Denis Novokshanov a , Sebastian Münstermann a * a Steel Institute, RWTH Aachen University, Intzestraße 1, 52072 Aachen, Germany Ultra-low cycle fatigue (ULCF) loading conditions raise a complex problem for design and safe exploitation of steel constructions in seismic active zones on our planet. The investigation of the damage and failure of steel constructions under loading with large strain amplitude can contribute to the development of safety assessments for earthquake-resistant steel structures. Damage mechanics provide a good approach for the description of damage and failure of materials and structures under ULCF loading. In the frame of the presented work a coupled continuum damage mechanic material model based on Yoshida-Uemori (YU) plasticity model (Yoshi a and Uemori 2003) and effective strain oncept (Ohata and Toyoda 2004) is presente . In comparison with the Armstrong-Frederik and Chaboche plasticity models (Armstrong and Frederick 1966, Chaboche 1989) YU model provides a better description for plastic material properties. Combination of YU-model model with effective strain concept and coupled damage allows using the presented model as a powerful instrument for material characterization and optimization of structures under ULCF loading. The developed damage mechanics model is validated on cyclic tests of small scale samples under loading with large strain amplitudes. It is capable to predict the force-displacement response and number of cycles to fracture. Additionally, the presented model is applicable for the simulation of large scale tests. The use of the proposed models for development of steel safety assessments and transfer of the material model parameters for 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Safety assessment of steels under ULCF loading conditions with damage mechanics model Yidu Di a , Denis Novokshanov a , Sebastian Münstermann a * a Steel Institute, RWTH Aachen University, Intzestraße 1, 52072 Aachen, Germany Abstract Ultra-low cycle fatigue (ULCF) loading conditions raise a complex problem for design and safe exploitation of steel constructions in seismic active zones o our planet. The investigation of the da age and failure of steel cons ructions und r l ading with larg strain amplitud ca contribute to the d velopment of safety assessments f r earthquake-res stant ste l structures. Damag mechanics provide a good approach for the description of damage and failure of materials and structures under ULCF lo din . In the frame f th presented w rk a couple continuum da age mechanic materi l model based on Yoshi a-Uemori (YU) plasticity model (Yoshida and Uemori 2003) and effective str in con ept (Oh a nd Toyod 2004) is present d. In comparison w th th Armstrong-Fre e ik nd Chaboche plasticity models (Armstr ng and Frederick 1966, Chaboche 1989) YU model pr vides a b tte de c iption for plastic mat rial properties. Combination of YU-model model with effective strain concept and coupled damage allow using the presented mode as a powerful instrument for material characterization and op imization of structures un er ULCF l ading. The developed damage mechanics model is validated on cyclic tests of small scale samples under loading with large strain amplitudes. It is capable to predict the force-displacement response and number of cycles to fracture. Addit onally, the presented model is applicable for the simula ion of large cale tests. The use of the proposed models for development of eel safety assessments and transfer of the material model parameters for modeling of large steel structures are discussed. © 2016 The Authors. Published by Elsevier B.V. Peer-review under espons bility of the Scientific Committee of ECF21. 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. modeling of large steel structures are discussed. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: Failure prediction; Damage mechanics model; Effective strain concept; ULCF Abstract

Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation. Keywords: Failure prediction; Damage mechanics model; Effective strain concept; ULCF

* 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. * Corresponding author. Tel.: +49-0241-8025422; fax: +49-0241-8092253. E-mail address: Sebastian.muenstermann@iehk.rwth-aachen.de * Corresponding author. Tel.: +49-0241-8025422; fax: +49-0241-8092253. E-mail ad ress: Sebastian.muenstermann@iehk.rwth-aachen.de

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.2016.06.082