PSI - Issue 13

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 Structural Integrity 13 (2018) 1651–1656 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. ECF22 - Loading and Environmental effects on Structural Integrity Chemical method of fatigue and corrosion fatigue crack growth arrest in steels by metal treatment with the special technological environment Ya. Khaburskyi*, H. Nykyforchyn Karpenko Physico-Mechanical Institute of the National Academy of Sciences of Ukraine, Lviv, 79060, Ukraine Abstract Novel method of fatigue crack growth arrest in structural steels based on artificial creation of crack closure effect is proposed. Special technological environment is used which, falling into a crack cavity, forms solid products there. These products practically totally fill up a crack cavity and serve as a wedge which prevents crack closure during a period of unloading and, respectively, cyclic deformation in a crack tip. Fatigue crack growth curves are built for low alloyed steel without and with crack treatment which demonstrate crack arrest in a wide range of stress intensity factor (SIF) Δ K , from the threshold level up to almost fatigue fracture toughness K fc . i.e for the whole actual range of Δ K . The peculiarity of artificial crack closure is accentuated: a decrease of effective Δ K is accompanied by an increase of a middle level of SIF therefore a risk of stress corrosion cracking and corrosion fatigue rises. This factor is especially important for long-term operated steels which lost their initial brittle fracture resistance. The interaction of active components of the technological environment with a metal at the crack surface which provides formation of solid products in a crack cavity is analyzed. Some technological aspects for practical application of the proposed method are considered. © 2018 The Authors. Published by Elsevier B.V. Peer-review und r responsibility of the ECF22 organizers. Keywords: fetigue, orrosion fetigue, crack closur , crack growth arrest 1. Introduction Fracture of materials, structures or laboratory specimens due to cyclic loading is always accompanied by fatigue crack growth. Therefore retardation of fatigue crack growth means an increase of fatigue strength or at least a period of subcritical crack growth. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. ECF22 - Loading and Environmental effects on Structural Integrity Chemical method of fatigue and corrosion fatigue crack growth arrest in steels by metal treatment with the special technological environment Ya. Khaburskyi*, H. Nykyforchyn Karpenko Physico-Mechanical Institute of the National Academy of Sciences of Ukraine, Lviv, 79060, Ukraine Abstract Novel method of fatigue crack growth arrest in structural steels based on artificial creation of crack closure effect is proposed. Special technological environment is used which, falling into a crack cavity, forms solid products there. These products practically totally fill up a crack vity and serve a a wedge which prevents crack closure during a period of unloading and, respectively, cyclic def rmation in tip. Fatigue crack gro th curves are built for low alloyed steel without and with crack treatment which demonstrate crack arrest in a wide ran e of stress intensity factor (SIF) Δ K , from the threshold level up to almost f tigu fracture toughn ss K fc . i.e fo the whole actual range of Δ K . The p culiarity f artificial crack closure i accentuated: a decrease of effective Δ K is accompani d by an increase of a middle level of SIF therefore a isk of st ess orrosion cracking and corrosion fatigu rises. Thi fa tor is especially important or long-t rm operated ste ls which lost their initial brittle fracture resistance. The interaction of active components of the technolo ical environ ent with a metal at the crack su face which provides formati n of solid products in a rack avity is analyzed. Some technological as ct for practical pplication of the pr posed method are considered. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: fetigu , corrosion fetigue, crack closure, crack growth arrest 1. Introduction Fracture of materials, structures or laboratory specimens due to cyclic loading is always accompanied by fatigue crack growth. Therefore retardation of fatigue crack growth means an increase of fatigue strength or at least a period of subcritical crack growth. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation.

*Corresponding author. E-mail address: khabursky.yaroslav@gmail.com *Corresponding author. E-mail ad ress: k abursky.yaroslav@gmail.com

* 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.

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.2018.12.346