PSI - Issue 2_B

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com cienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Struc ural Integrity 2 (2016) 1771–178 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2016) 000–000 Available online at www.sciencedirect.com Scie ceDirect Structural Integrity Procedia 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 Wear efficiency of oil-well casings exposed to rotating tooljoints Udaya B Sathuvalli*, Shaikh Rahman, James Wooten and P V Suryanarayana Blade Energy Partners, 2600 Network Boulevard, Suite 550, F isco, TX 75034, USA Abstract Wall loss due to adhesive wear between a rotating drillstring tooljoint and the softer inner surface of a steel casing is often encountered while drilling deviated oil and gas wellbores. Despite the significance of the problem in the drilling industry, there is little data on casing wear efficiencies in the public domain. A large body of data collected during a joint industry project was deemed proprietary to participants who sponsored the private project (DEA-42). In this paper, we outline an approach to determine the wear efficiency of unlubricated surfaces by using the roughness parameters and material properties of the wearing surface. Our method combines the classic Greenwood & Williamson (1966) approach with the Archard-Rabinowicz (1953) interpretation of wear efficiency. The Greenwood & Williamson study models surface morphology as an ensemble of randomly distributed asperities. Archard (1953) interprets wear efficiency as the probability of a wear particle being created during an encounter of asperities between sliding surfaces. By using these notions we derive a formula for wear efficiency of an unlubricated surface as a function of the standard deviation of its summit height distribution, the summit radius, the hardness and contact modulus. Our predicted wear efficiencies are in the range of 1.5 - 5 ×10 -3 . These values agree well with published results for similar metals sliding on each other without lubrication. Future work along these lines will consider the effect of lubricants on adhesive wear efficiency. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: Wear efficiency, surface roughness, Adhesive wear, Greenwood-Williamson model, Archard’s law of adhesive wear, casing wear 1. Introduction In the oilfield, casing wear is encountered while drilling deviated wellbores and while drilling through buckled casing strings (Lewis and Miller, 2009). The loss of material from the casing affects the internal and external pressure ratings of the casing and may become a preferential site of corrosion. Studies of casing-tooljoint interaction show a qualitative change from abrasive wear to adhesive wear at a threshold contact pressure of ~250 psi (1.7 MPa) (Bradley, 1975). Since contact pressures are usually above this threshold, drilling engineers use the adhesive wear model of Archard (1953). This model requires an experimentally measured parameter known as “wear efficiency”, a function of the mating surfaces and the interceding lubricant. Despite the significance of the problem in the drilling industry, there is little data on wear efficiencies in the public domain. A large body of data collected during a joint industry project was deemed proprietary to participants who sponsored the private project (DEA-42). To date, with the exception of the study by White and Dawson (1987), there are few published data on wear efficiencies for OCTG (Oil Country Tubular Goods) steels. Wear assessments in the drilling industry are frequently based on small or large scale tests that seek to mimic expected downhole conditions (DEA-42, Doering et al., 2011) as closely as possible. Such tests while useful, have limited validity since they do not allow generalization. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy ear efficiency of oil- ell casings exposed to rotating tooljoints Udaya B Sathuvalli*, Shaikh Rahman, James ooten and P V Suryanarayana Blade Energy Partners, 2600 Network Boulevard, Suite 550, Frisco, TX 75034, USA Abstract Wall loss due to adhesive wear between a rotating drillstring tooljoint and the softer inner surface of a steel casing is often encountered while drilling deviated oil and gas wellbores. Despite the significance of the problem in the drilling industry, there is little data on casing wear efficiencies in the public domain. A large body of data collected during a joint industry project was deemed proprietary to participants who sponsored the private project (DEA-42). In this paper, we outline an approach to determine the wear efficiency of unlubricated surfaces by using the roughness parameters and material properties of the wea ng surfa e. Our metho combines the classic Greenwood & Williamson (1966) approach with the Archard-Rabinowicz (1953) interpretation of wear efficiency. The Greenwood & Williamson study models surface morphology as an ensemble of randomly distributed asperities. Archard (1953) interpr t wear efficiency as the probability of a wear particle being created during an encounter of asperities between sliding surfaces. By using these notions we derive a formula for wear efficiency of an unlubricated surface as a function of the standard deviation of its summit height distribution, the summit radius, the hardness and contact modulus. Our predicted wear efficiencies are in the range of 1.5 - 5 ×10 -3 . These values agree well with published results for similar metals sliding on each other without lubrication. Future work along these lines will consider the effect of lubricants on adhesive wear efficiency. © 2016 The Authors. Published by Elsevier B.V. Pe r-r v ew und r responsibility of the Scientific Committee of ECF21. Keywords: Wear efficiency, surface roughness, Adhesive wear, Greenwood-Williamson model, Archard’s law of adhesive wear, casing wear 1. Introduction In the oilfield, casing wear is encountered while drilling deviated wellbores nd while drilling throug buckled casing strings (Lewis and Miller, 2009). The loss of material from the casing affects the internal and external pressure ratings of the casing and may become a preferential site of corrosion. Studies of casing-tooljoint interaction show a qualitative change from abrasive wear to adhesive wear at a threshold contact pressure of ~250 psi (1.7 MPa) (Bradley, 1975). Since contact pressures are usually above this threshold, drilling engineers use the adhesive wear model of Archard (1953). This model requires an experimentally measured parameter known as “wear efficiency”, a function of the mating surfaces and the interceding lubricant. Despite the significance of the problem in the drilling industry, there is little dat wear efficiencies in the public domain. A large body of data collected during a joint industry project was deemed proprietary to participants who sponsored the private project (DEA-42). To date, with the exception of the study by White and Dawson (1987), there are few published data on wear efficiencies for OCTG (Oil Country Tubular Goods) steels. Wear assessments in the drilling industry are frequently based on small or large scale tests that seek to mimic expected downhole conditions (DEA-42, Doering et al., 2011) as closely as possible. Such tests while useful, have limited validity since they do not allow generalization. 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-revie under responsibility of the Scientific Committee of ECF21. © 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. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt * Corresponding author. Tel.: +1-972-712-8407; fax: +1-972-712-8408. E-mail address: usathuvalli@blade-energy.com * Corresponding author. Tel.: +1-972-712-8407; fax: +1-972-712-8408. E-mail ddress: u athuvalli@blade-energy.com

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.2016.06.223 2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer- eview under responsibility of the Scientific Committee of ECF21. 2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-revi w under responsibility of the Scientific Committee of ECF21.