PSI - Issue 13

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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 13 (2018) 877–885 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. ECF22 - Loading and Environmental effects on Structural Integrity Influence of Loading Rate on the Fracture Toughness of High Strength Structural Steel A. A. Alabi a,b, *, P. L. Moore c , L. C. Wrobel d , J. C. Campbell a,b , W. He e a Department of Mechanical and Aerospace Engineering, Brunel University London, Uxbridge, UB8 3PH, UK b National Structural Integrity Research Centre, Granta Park Great Abington, Cambridge, CB21 6AL, UK c TWI Ltd, Granta Park Great Abington, Cambridge CB21 6AL, UK d Institute of Materials and Manufacturing, Brunel University London, Uxbridge, UB8 3PH, UK e Lloyds Register Global Techn logy Centre, Southampton, SO16 7QF, UK Abstract It is known that rates of loading influence the fracture behaviour of most ferritic steels. High loading rates could change a stable ductile tearing behaviour to an unstable brittle fracture by altering the ductile-to-brittle transition curve. This is predicted to be material dependent, with lower strength structural steels showing a larger tensile property loading rate sensitivity compared to high strength structural steels. A programme of mechanical testing was carried out on S690QL and S960QL to determine the influence of loading rate on the fracture behaviour of high strength structural steels with yield strength > 690 MPa and yield-to-tensile ratio above 0.90. The loading rates considered are those anticipated in offshore in-service conditions, with K-rates up to the order of magnitude of 10 6 MPa√m/s. Results from tensile tests show that the strengths of these grade of steels are relatively unaffected by the effect of loading rate. However, brittle fracture, which is controlled by material strengthening as a result of principal stress in front of the crack, is both loading rate and temperature dependent. Results from tests at quasi-static and elevated loading rates show changes in the fracture behaviour in terms of transition temperature. A shift to a higher ductile-to-brittle transition temperature was observed as th loading rate incr ases. This was associated with a reduction in the fracture toughness value on the lower t ansition region. The reference temperature, T 0 , at a K-rat of 1 MPa √m/s using Master Curve concep s is estimated to be around -116 °C and -108 °C for Ch rpy sized pre-cracked and standa d (25x25 mm) SENB specimens respectively, under quasi-static conditions for S690QL. The dynamic T 0,d is -70.4 °C in the same steel for Charpy-s zed p e-cracke specimens at K-rates up to 10 6 MPa √m/s. ECF22 - Loading and Environmental effects on Structural Integrity Influence of Loading Rate on the Fr cture Toughness of High Strength Structural Steel A. A. Alabi a,b, *, P. L. Moore c , L. C. Wrobel d , J. C. Campbell a,b , W. He e a Department of Mechanical and Aerospace Engineeri g, Brun l University London, Uxbridge, UB8 3PH, UK b National Structural Integrity Research Centre, Granta Park Great Abington, Cambridge, CB21 6AL, UK c TWI Ltd, Granta Park Great Abingt n, Cambri ge CB21 6AL, UK d Institute of Materials and Manufacturing, Brunel University London, Uxbridge, UB8 3PH, UK e Lloyds Register Global Technology Centre, Southampton, SO16 7QF, UK Abstract It is known that rates of loading influence th fracture behaviour of mo t fer itic s eels. High loading rates could change a stable ductile tearing behaviour to an unstable brittle fracture by altering the d ctile-to-brittle transition curve. This is pr d cted to be material dependent, with lower strength structural steels showing a larger tens l property loading rate sensitivity compar d to high strength structural steels. A programme of mechan al testing was carr ed out on S690QL and S960QL to de ermine the influence of loading rate on the fracture behaviour of high strength structural steels with yield strength > 690 MPa and yield-to-tensil ratio above 0.90. Th loading rates considered are those anticipat in offshore in-service conditions, with K-rates up to the order f magnitude of 10 6 MPa√m/s. Results from tensile tests show that the strength of these grad of steels r relatively unaffected by the effec of loading rate. H wever, brittle fr cture, which is controlled by mater al streng h ni g as a result of princi al s ress i front of the crack, s both loadi g r te and temper ure dependent. Re ults from t sts at q asi-static and l vated lo ding rat s show changes in the fractur behaviour in terms of transition temperatur . A shift to a higher du tile-to-brit le transition te perature was observed as the lo ding rat increases. This was associated with a redu tion in th fractur oughness value on he lower ra ition region. The referen e temperature, T 0 , a a K-rate of 1 MPa √m/s using Master Curve conc pts is estimated t be around -116 °C and -108 °C for Charpy sized pre-cracked and standard (25x25 mm) SENB specimens respectively, under quasi-static conditions for S690QL. The dynamic T 0,d is -70.4 °C in the same ste l for Charpy-sized pre-cracked specimens at K-rates up to 10 6 MPa √m/s. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers.

* Corresponding author. Tel.: +447572141987 E-mail address: aderinkola.alabi@brunel.ac.uk

* Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452-3216 © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. 2452-3216 © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. * Corresponding author. Tel.: +447572141987 E mail address: ad rinkola.alabi@brunel.ac.uk

2452-3216  2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. 10.1016/j.prostr.2018.12.166

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