PSI - Issue 2_B

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 2 (2016) 509–516 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2016) 000–000 il l li t . i ir t. i i Structural I tegrit r ce ia 00 (2016) 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. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Stress corrosion cracking of gas pipeline steels of different strength O. I. Zvirko a *, S. F. Savula b , V. M. Tsependa b , G. Gabetta c , H. M. Nykyforchyn a a Karpenko Physico-Mecha ical Institute of the Natio al Academy of Sc ences of Ukraine, 5, Naukova St., 79060 Lviv, Ukraine b Public Joint-Stock Company “UKRTRANSGAZ, Affiliate “Lvivtransgaz”, 3, Rubchaka St., 79026 Lviv, Ukraine; c eni S.p.A., 1, Piazz le Mattei, 00144 Rome, Italy Abstract With the development of th n tural gas industry, gas transmission pipeli es have been developed rapidly in terms of safety, economy and efficiency. Our recent studies have shown that an important factor of main pipelines serviceability loss under their long-term service is the in-bulk metal degradation of the pipe wall. This leads to the loss of the initial mechanical properties, primarily, resistance to brittle fracture, which were set in engineering calculations at the pipeline design stage. At the same time stress corrosion cracking has been identified as one of the predominant failures in pipeline steels in humid environments, which causes rupture of high-pressure gas transmission pipes as well as serious economic losses and disasters. In the present work the low-carbon pipeline steels with different strength levels from the point of view of their susceptibility to stress corrosion cracking in the as-received state and after in-laboratory accelerated degradation under environmental conditions similar to those of an acidic soil were investigated. The main objectives of this study were to determine whether the development of higher strength materials led to greater susceptibility to stress corrosion cracking and whether degraded pipeline steels became more susceptible to stress corrosion cracking than in the as-received state. The procedure of accelerated degradation of pipeline steels was developed and introduced in laboratory under the combined action of axial loading and hydrogen charging. It proved to be reliable and useful to performed laboratory simulation of in-service degradation of pipeline steels with different strength. The in-laboratory degraded 17H1S and X60 pipeline steels tested in the NS4 solution saturated with CO 2 under open circuit potential revealed the susceptibility to stress corrosion cracking, reflected in the degradation of mechanical properties, and at the same time the degraded X60 steel showed higher resistance to stress corrosion cracking than the degraded 17H1S steel. Fractographic observation confirmed the pipeline steels hydrogen embrittlement caused by the permeated hydrogen. t t , , , t i , t l . . i o a , S. . l b , . . b , . tt c , . . a a r e k ysic - ec nic l I stit te f t e ti n l c e y f cie ces f kr i e, , k v t., viv, Ukrai e b lic J i t- t ck y , ffili te vivtr s z , , c k t., viv, kr i e; c e i . . ., , i zz le ttei, e, It ly str t it t l t f t e at r l s i str , s tr s issi i lin s l r i l i t r s f s f t , m and ffi i ncy. ur recent studies have shown that an important factor of main pipelines serviceability loss under their l -t r s r i is t i - l t l r ti f t i ll. is l s t t l ss f t i iti l i l r rti s, ri ril , r sistance to brittle fracture, which were set in engin ri l l ti s t t i li si st . t t s ti str ss rr si r i s i tifi s f t r i t f il r s i i li st ls i i ir ts, i s s r t r f i - r ss r s tr s issi i s s ll s s ri s i l ss s is st rs. In the pres t r t l - r i li st ls it iff r t str t l ls fr t i t f i f t ir s s ti ilit t str ss rr si r i i t s-r i st t ft r i -l r t r l r t r ti under environmental c iti s si il r t t s f i i s il wer i sti t . i j ti s f t is st r t t r i t r t l t f i r str t t ri ls l t r t r s s ti ilit to stress corrosion cracking and whether degraded pipeline steels became r s s ti l t str ss rr si n cracking than in the as-received state. The procedure of accelerated degradation of pipeline st ls s l i tr i l r t ry under the combined action of axial loading and hydrog r i . It r t r li l s f l t rf r l r tory simulation of in-service degradation of pipeline steels with different strength. i -l r t r r i li st ls t st i t s l ti s t r t it 2 r pe ir it t ti l revealed t s s ti ilit t str ss rr si r i , r fl ted in the degradation of mechanical properties, and at the s ti t r st l s i r r sist t str ss corrosion cracking t t r 17H1S steel. r t r i s r ti fir t i li st ls r rittl t s t r t r .

© 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. © 2016 The Authors. Published by Elsevier B.V. r-r i r r s si ilit f t i tifi itt f . Copyright © 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativ commons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of the Scientifi Committee of ECF21.

Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation. Keywords: stress corrosion cracking; slow strain rate tests; mechanical properties; pipeline steel. ey r s: stress c rr si crac i ; sl strai rate tests; ec a ical r erties; i eli e steel.

* 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 ECF21. - e t rs. lis e lse ier . . r-r i r r s si ilit f t i tifi itt f . * Corresponding author. Tel.: +38032-229-6294; fax: +38032-264-9427. E-mail address: zvi@ipm.lviv.ua, olha.zvirko@gmail.com (O. I. Zvirko) rres i a t r. el.: - - ; fa : - - . ress: z i i .l i . a, l a.z ir ail.c ( . I. ir ) - il

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Copyright © 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ). Peer review under responsibility of the Scientific Committee of ECF21. 10.1016/j.prostr.2016.06.066