PSI - Issue 2_B

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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.2016.06.218 ∗ Corresponding author. Tel: + 44 (0)161 306 4286. E-mail address: nicolas.larrosa@manchester.ac.uk 2452-3 16 c ⃝ 2016 The Authors. Published by Elsevi r B.V. Peer-review under responsibility of the Scientific Comm ttee f ECF21. Structural integrity assessm nt procedures for components containing flaws, e.g. cr cks, usually evaluate fitness for-service (FFS) by means f Engineering Critical Assessments (ECA). ECA is based on damage tolerance prin iples (fracture mechanics) d is used to ass ss wheth r or not a defective component is in a safe condition from elastic plastic fract r and plastic collapse under specified loa ing and environmental conditions. For elastic-plastic frac ure the driving force is quantified by a single parameter ( K , CTOD or J -int gral), and compared with the respective critical value to failure, usually obtained from testing standard laboratory specimens. In standard fracture toughness testing, such as ASTM E399 (2005) and ASTM E1820 (2006), deeply cracked compact tension, C(T), or single edge notch ∗ Corresponding author. Tel: + 44 (0)161 306 4286. E-mail address: nicolas.larrosa@manchester.ac.uk 2452-3216 c ⃝ 2016 The Auth rs. Publi hed by Elsevier B.V. Pe r-review under responsibility of the Scientific Committee of ECF21. Structural integrity assessment procedures for components containing flaws, e.g. cracks, usually evaluate fitness for-service (FFS) by means of Engineering Critical Assessments (ECA). ECA is based on damage tolerance principles (fracture mechanics) and is used to assess whether or not a defective component is in a safe condition from elastic plastic fracture and plastic collapse under specified loading and environmental conditions. For elastic-plastic fracture, the driving force is quantified by a single parameter ( K , CTOD or J -integral), and compared with the respective critical value to failure, usually obtained from testing standard laboratory specimens. In standard fracture toughness testing, such as ASTM E399 (2005) and ASTM E1820 (2006), deeply cracked compact tension, C(T), or single edge notch ∗ Corresponding author. Tel: + 44 (0)161 306 4286. E-mail address: nicolas.larrosa@manchester.ac.uk 2452-3216 c ⃝ 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. 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 The use of SE(T) specimen fracture toughness for FFS assessment of defects in low constraint conditions J.-J. Han a , N.O. Larrosa b, ∗ , R.A. Ainsworth c , Y.-J. Kim a a Department of Mechanical Engineering, Korea University, Anam-Dong, Seongbuk-Gu Seoul 136-701, Korea. b School of Materials, The University of Manchester, Manchester M13 9PL, United Kingdom c School of Mechanical, Aerospace & Civil Engineering, The University of Manchester, Manchester M13 9PL, United Kingdom. Abstract Due to the loss of constraint, shallow cracked specimens can ‘absorb’ more nergy than deeply cracked specimens commonly used to define the critical value to fracture and therefore exhibit a higher fracture toughness. The increase in energy absorption allows a reduction in the inherent conservatism when assessing components in low constraint conditions. This study addresses the benefit of using shallow cracked SE(T) fracture toughness specimens in fitness for service (FFS) assessment of defects under low constraint conditions, e.g. blunt defects or shallow cracks. Tearing resistance curves (J-R curves) have been constructed by means of a virtual test framework to determine crack initiation and propagation for shallow cracked SE(T) specimens and parametric notched C(T) specimens. The e ff ect of constraint level on J-R curves is compared. It is observed that most of the blunted C(T) specimens analysed exhibit the same or a lower toughness value than that of a shallow cracked SE(T) specimen. The results are used to show how reduced conservatism can be made in defect assessment of blunt defects or in cases in which reduced constraint conditions can be demonstrated. c ⃝ 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: Apparent fracture toughness, Constraint e ff ect, Shallow defects, Blunt defects, J-R curves, Stress-modified fracture strain model, Structural integrity Structural integrity assessment procedures for components containing flaws, e.g. cracks, usually evaluate fitness for-service (FFS) by means of Engineering Critical Assessments (ECA). ECA is based on damage tolerance principles (fracture mechanics) and is used to assess whether or not a defective component is in a safe condition from elastic plastic fracture and plastic collapse under specified loading and environmental conditions. For elastic-plastic fracture, the driving force is quantified by a single parameter ( K , CTOD or J -integral), and compared with the respective critical value to failure, usually obtained from testing standard laboratory specimens. In standard fracture toughness testing, such as ASTM E399 (2005) and ASTM E1820 (2006), deeply cracked compact tension, C(T), or single edge notch 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy The use of SE(T) specimen fracture toughness for FFS assessment of defects in l w constraint conditions J.-J. Han a , N.O. Larrosa b, ∗ , R.A. Ainsworth c , Y.-J. im a a Department of Mechanical Engineering, Korea University, Anam-Dong, Seongbuk-Gu Seoul 136-701, Korea. b School of Materials, The University of Manchester, Manchester M13 9PL, United Kingdom c School of Mechanical, Aerospace & Civil Engineering, The University of Manchester, Manchester M13 9PL, United Kingdom. Abstract Due to the loss of constraint, shallow cracked specimens can ‘absorb’ more energy than deeply cracked specimens commonly used to define the critical value to fracture and therefore exhibit a higher fracture toughness. The increase in energy absorpti n allows a reduction in the inherent conservatism when assessing compone ts in low constraint conditions. This study addresses the benefit of using sh llo cracke SE(T) fracture toughness specimens in fitness for servi e (FFS) assessm nt of defects under low constraint conditions, e.g. blunt d fects or shallow cracks. Tearing resistance curves (J-R curves) have been cons ructed by means of a virtual test framework o determine crack initiation and propagation for shallow cracked SE(T) speci ens and parametric notched C(T) specimens. The e ff ect of constraint level on J-R curves is c mpared. It is observed that most of the blunted C(T) specimens analysed exhibit the same or a lower toughness value than that of a shallow cracked SE(T) specimen. The results are used to show how reduced conservatism can be made in defect assessment of blunt defects or in cases in which reduced constraint conditions can be demonstrated. c ⃝ 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: Apparent fracture toughness, Constraint e ff ect, Shallow defects, Blunt defects, J-R curves, Stress-modified fracture strain model, Structural integrity 1. Introduct on 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy The use of SE(T) specimen fracture toughness for FFS assessment of defects in low constraint conditions J.-J. Han a , N.O. Larrosa b, ∗ , R.A. Ainsworth c , Y.-J. Kim a a Department of Mechanical Engineering, K re University, Anam-Dong, Seongbuk-Gu Seoul 136-701, Korea. b School of Materials, The University of M nchester, Manchester M13 9PL, United Kingdom c School of Mechanical, Aerospace & Civil Engineering, The University of Manchester, Manchester M13 9PL, United Kingdom. Abstract Due to the loss of constraint, shallow cracked specimens can ‘absorb’ more energy than deeply cracked specimens commonly used to define the critical value to fracture and therefore exhibit a higher fracture toughness. The increase in energy absorption allows a reduction in the inherent conservatism when assessing c mponents in low constraint conditions. This study addresses the benefit of using shallow cracked SE(T) fracture toughness specimens in fitness for service (FFS) assessment of defects under low constraint conditions, e.g. blunt defects or shallow cracks. Tearing resistance curves (J-R curves) have been constructed by means of a virtual test framework to determine crack initiation and propagation for shallow cracked SE(T) specimens and parametric notched C(T) specimens. The e ff ect of constraint level on J-R curves is compared. It is observed that most of the blunted C(T) specimens analysed exhibit the same or a lower toughness value than that of a shallow cracked SE(T) specimen. The results are used to show ow reduc d conservatism can be made in defect assessment of blunt defects or in cases in which reduced constraint conditions can be demonstrated. c ⃝ 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: Apparent fracture toughness, Constraint e ff ect, S allow defects, Blu t defects, J-R curves, Stress-modified rac ure strain model, Structural integrity 1. Introductio Copyright © 2016 The Auth rs. Published by Elsevier B.V. This is an open access articl u der the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). P revie under esponsibility 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. 1. Introduction Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation. * Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt