PSI - Issue 13

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 Structural Integrity 13 (2018) 1895–19 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Int grity 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. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. ECF22 - Loading and Environmental effects on Structural Integrity Effect of crack length on fracture toughness of welded joints with pronounced strength heterogeneity Primož Štefane a *, Sameera Naib b , Stijn Hertelé b , Wim De Waele b , Ne ad Gubeljak a a Faculty of Mechanical Engineering, Smetanova 17, Maribor 2000, Slovenia b Soete Laboratory, Dept. of EEMMeCS, Ghent University, Technologiepark Zwijnaarde 903, Ghent 9052, Belgium Abstract The integrity assessment of repaired welds is dependent on accurate char cterization of their fracture behavior and limit load estimation. The final weld consists multiple microstructures due to different weld co sumables used f r repair welding. As a result, a large degree of heterogeneity is to be expected. The variation of mechanical nd fracture properties within the weld influences the fracture behavior and limit load capacity of repaired weld. This motivated the authors of this work to adapt existing testing methods in order to characterize the fracture behavior of repair welds and to develop limit load solutions which include the effects of weld heterogeneity. This work focuses on the idea of implementing T-stress in characterization of fracture toughness at the onset of crack tip blunting. By normalizing J-integral by stress biaxiality coefficient β , obtained from T-stress solution, a new fracture toughness parameter is derived which tends to be dependent only on the distance from crack tip to interface between two mismatched weld materials. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: Repair weld; bi-materi l interface; T-stress; Crack driving force Nome clature ECA Engineering critical assess ent ECF22 - Loading and Environmental effects on Structural Integrity Effect of crack length on fracture toughness of welded joints with pronounced strength heterogeneity Primož Štefane a *, Sameera Naib b , Stijn Hertelé b , Wim De Waele b , Nenad Gubeljak a a Faculty of Mechanical Engineering, Smetanova 17, Maribor 2000, Slovenia b Soete Laboratory, Dept. of EE MeCS, Ghe t University, Technologiepark Zwijnaarde 903, Ghent 9052, Belgium Abstract The integrity assessment of repaired welds is dependent on accurate characterization of their fr cture behavior and limit load estim tion. final weld consists f multiple microstructures due to differ nt weld consumables used for repair welding. As a result, a large degree of heterogeneity is to be expected. The variation of mechanical and fracture properties within the weld influences the fractur b havior and limit load capacity of r paired weld. This motivated the authors of this w rk to adapt existing t sting m thods in order to characterize the fracture behavior of repair welds and to develop limit load olutions which includ the effects of weld heterogeneity. T is work focuses on the idea of impl menting T-stress in characterization of fracture toughness at the ons t of crack tip blunting. By normalizing J-integral by stress biaxiality coefficient β , obtained from T-stress solution, a new fracture t ughness parameter is derived which tends to be dependent only on the distance from crack tip to interfac between two mismat hed weld materi ls. © 2018 The Authors. Publishe by Elsevier B.V. Peer-review under res onsibili y of the ECF22 organizers. Keywords: Repair weld; bi-material interface; T-stress; Cr ck driving force Nomenclature ECA Engineering critical assessment FFS Fitness for service

FFS CDF CDF OM

Fitness for service Crack driving force Crack driving force

© 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. OM Overmatched Overmatc ed U Undermatched

UM M

Undermatched Mismatch ratio defined as M=weld material R p0,2 / base material R p0,2 Mismatch ratio defined as M=weld material R p0,2 / base material R p0,2

M HSLA HSLA

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

High strength low alloyed steel

* 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 r sponsibility of the ECF22 organizers. * Corresponding author. Tel.: +386-2-220-7704; fax: +0-000-000-0000 . E-mail address: primoz.stefane2@um.si * Corresponding author. Tel.: +386-2-220-7704; fax: +0-000-000-0000 . E-mail ad ress: primoz.stefane2@um.si

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016.

2452-3216  2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. 10.1016/j.prostr.2018.12.319