PSI - Issue 5

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 5 (2017) 989–996 Available online at www.sciencedirect.com 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. Influence of surface morphology on fatigue behavior of metastable austenitic stainless steel AISI 347 at ambient temperature and 300°C Marek Smaga a* , Robert Skorupski a , Patrick Mayer b , Benjamin Kirsch b , Jan C. Aurich b , Indek Raid c , Jörg Seewig c , Ji ří Man d , Dietmar Eifler a , Tilmann Beck a a Institute of Materials Science and Engineering, University of Kaiserslautern, P.O. Box 3049, 67653 Kaiserslautern, Germany b Institute for Manufacturing Technology and Production Systems,University of Kaiserslautern, P.O. Box 3049, 67653 Kaiserslautern, Germany c Institute for Measurement and Sensor-Technology,University of Kaiserslautern, P.O. Box 3049, 67653 Kaiserslautern, Germany d Institute of Physics of Materials ASCR, Žižkova 22, 616 62 Brno, Czech Republic Abstract The effect of surface modification by cryogenic turning on fatigue behavior of metastable austenitic stainless steel AISI 347 was investigated in stress-controlled fatigue tests at ambient temperature (AT) and 300 °C in air. Five different surface morphologies were manufactured by the variation of turning parameters – with and without cryogenic CO 2 snow cooling and feed velocity as well as by the application of polishing for reference surfaces with a very small surface roughness. For a comprehensive characterization of th surface and near surface morphol gy, X-ray diffraction investigations were per ormed. Three phases (  -austenite,  ´-marten it and  -m r ensite) were detected in the ne r surface microstructure after cryogenic turning while after turning without cryogenic cooling the only microstructural constituent was γ -austenite. Moreover, residual stress state, micro hardness and surface roughness play an important role in surface morphology. The experimental data on the cyclic deformation behavior and stress-strain response of all surface morphologies are reported. Reference specimens with purely austenitic surface microstructure show the highest plastic strain amplitude during cyclic loading at both AT and 300°C. At elevated temperature these specimens achieved the shortest fatigue life. Martensitic surface layers induced by cryogenic turning result in the reduction of plastic strain amplitude during c clic loading and significantly enhance fatigue life at both tested temperatures. 2 nd International Conference on Structur l Integrity, ICSI 2017, 4-7 September 2017, Funchal, Madeira, Portugal Influence of surfac morphology on fatigu behavior of metastable austenitic stainless steel AISI 347 at ambient temperature and 300°C Marek Smaga a* , Robert Skorupski a , Patrick Mayer b , Benjamin Kirsch b , Jan C. Aurich b , Indek Raid c , Jörg Seewig c , Ji ří Man d , Dietmar Eifler a , Tilmann Beck a a Institute of Materials Science and Engineering, Univer ity of Ka serslautern, P.O. Box 3049, 67653 Kaiserslautern, Germany b Institute for Manufacturing Technology and Production Systems,University of K is slautern, P.O. Box 3049, 67653 K is slautern, Germany c Institute for Measurement and Sensor-Technology,University of Kaiserslautern, P.O. B x 3049, 67653 Kaiserslautern, Germany d Institute of Physics of Materials ASCR, Žižkova 22, 616 62 Brno, Czech Republic Abstract The effect of surface modification by c yogenic turning on fatigue behavior of metastable austenitic stainless steel AISI 347 was investigated in stress-controlled fatigue tests at ambient temperatur (AT) and 300 °C in air. Five different surface morphologies were manufactured by the variation of turning parameters – with nd without cryogenic CO 2 snow cooling and feed velocity as well s by the application of polishi g for eference surfaces with a very small surface roughness. For a comprehensive c aracterization of the su face and ear sur ace morphology, X-ray diffraction investigations were p rformed. Three phases (  -austenite,  ´-martensit and  -marten ite) wer detected in the near surface microstruct re aft r cryogenic turning while after turning without cryogenic cooli g the only micr structural c nstituent was γ -austenite. Moreove , r sidual stress state, micro hardness and surface roughne s play an important role in surface morphology. The experim ntal data on th cyclic deformation behavior and stress-strain response of all surface morphologies are reported. Reference specimens with purely austenitic surface microstructur show the high st plastic strain amplitude during cyclic loading at both AT and 300°C. At elevated temperature t se spec mens achieved th shortest fatigue life. Martensitic surface layers induced by cryogenic turning result in the reduction of plastic strain amplitude during cyclic loading and significantly enhance fatigue life at both tested temperatures. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Com ittee of ICSI 2017. © 2017 The Autho s. Publ shed by Elsevi r B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017. © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017 Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation. 2 nd International Conference on Structural Integrity, ICSI 2017, 4-7 September 2017, Funchal, Madeira, Portugal

Keywords: metastable austenitic stainless steels; martensite; surface morphology; cryogenic turning; fatigue Keywords: metastable austenitic stainless steels; martensite; surface morphology; cryogenic turning; fatigue

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. 2452-3216  2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017 10.1016/j.prostr.2017.07.150 * Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452 3216 © 2017 Th Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017. * Corresponding author. Tel.: +49-631-205-2762; fax: +49-631-205-2137. E-mail address: smaga@mv.uni-kl.de * Corresponding author. Tel.: +49-631-205-2762; fax: +49-631-205-2137. E-mail address: smaga@mv.uni-kl.de 2452-3216 © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017.