PSI - Issue 8

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com Scie ceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structu al Integrity 8 (2018) 174–183 ScienceDirect Structural Integrity Procedia 00 (2017) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2017) 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. Copyright © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibil ty of the Scientific Committee of AIAS 2017 Int r ational Conference on Stress Analysis AIAS 2017 International Conference on Stress Analysis, AIAS 2017, 6-9 September 2017, Pisa, Italy Accelerated cyclic plasticity models for FEM analysis of steelmaking components under thermal loads J. Srnec Novak a , L. Moro a *, D. Benasciutti b , F. De Bona a a Politechnic Department of Engineering and Architecture (DPIA), University of Udine, via delle Scienze 208, Udine 33100, Italy b Department of Engineering, University of Ferrara, via Saragat 1, 44122, Ferrara, Italy Abstract Steelmaking components are often subjected to thermo-mechanical loads applied cyclically. In this case the choice of a suitable cyclic plastic model to be used in the numerical simulation is a crucial aspect in design. Combined (kinematic and isotropic) model permits the cyclic material behavior to be captured accurately. On the other hand, such model often requires unfeasible computational time to arrive at complete material stabilization. Simplified or accelerated models have then been proposed to make simulation faster. In this work, the thermo-mechanical analysis of a round mold for continuous casting is addressed as a case study. Due to axi-symmetry, a plane model can be adopted. This permits a finite element (FE) analysis with a combined model to be performed until complete stabilization. A comparison with other models able to speed up the simulation (accelerated models with increased values of saturation speed, Prager and stabilized models) was performed. It was found that only accelerated models give equivalent strain range values that do not significantly differ from the (reference) combined model, independently fro the speed of saturation adopted. © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of AIAS 2017 International Conference on Stress Analysis. Keywords: cyclic plasticity models; finite element method; thermo-mechanical analysis AIAS 2017 International Conference on Stress Analysis, AIAS 2017, 6-9 September 2017, Pisa, Italy Acc lerated cyclic plasticity models for FEM analysis of steelmaking components under thermal loads J. Srnec Novak a , L. Moro a *, D. Benasciutti b , F. De Bona a a Politechnic Department of Engineering and Architecture (DPIA), University of Udine, via delle Scienze 208, Udine 33100, Italy b Department of Engineering, University of Ferrara, via Saragat 1, 44122, Ferrara, Italy Abstract Steelmaking omponents are often subjected to thermo-mech nical loads applied cyclically. In this case the choice of a suita l yclic plastic mod l to be used in the numerical simulation is a crucial aspect in d sign. Combined (kinematic a d isotropic) model permits the cyclic material behavio t b c ptured ccurately. O the other hand, s ch model often requires unfeasible compu tional ti e to arrive at complete material stabilization. Simplified or accelerated models have t en been proposed to mak simulation faster. In this work, the thermo-mech nical analysis of a round mold for continuous casting is addressed as a case study. Due to axi-symmetry, a pla e mo el can be a opted. This permits finit element (FE) anal sis with a ombin l to b performed until complete tabilizati n. A comp rison with other models abl to speed up the simulation (acc l rated odels with increased values of saturation speed, Prager and stabilized models) was performed. It was found that only accelerated models give equivalent strain range values that do not significantly differ from the (reference) combined model, independently from the speed of saturation adopted. © 2017 The Authors. Published by Elsevier B.V. P er-review under responsibility of th Scientific Committee of AIAS 2017 International Conference on Stress Analysis.

© 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: cyclic plasticity models; finite element method; thermo-mechanical analysis

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

* Corresponding author. Tel.: +39 0432 558048 E-mail address: luciano.moro@uniud.it * Corresponding author. Tel.: +39 0432 558048 E-mail address: luciano.moro@uniud.it

2452-3216 © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of AIAS 2017 International Conference on Stress Analysis. 2452-3216 © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of AIAS 2017 International Conference on Stress Analysis.

* 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 Copyright  2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of AIAS 2017 International Conference on Stress Analysis 10.1016/j.prostr.2017.12.019