PSI - Issue 2_A

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) 1789–1796 Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2016) 000–000 Available online at www.sciencedirect.com 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 Complete Williams Asymptotic Expansion Ne r The Crack Tips of Collinear Cracks of Equal Lengths in an Infinite Plane Medium Larisa Stepanova a , Pavel Roslyakov b a Samara State University, Akad. Pavlov 1, Samara 443011, Russia b Samara State University, Akad. Pavlov 1, Samara 443011, Russia, JSC ”SRC Progress”, Zemetsa str. 18, Samara 443009 Abstract The study is aimed at analytical determination of coe ffi cients in crack tip stress expansions for two collinear finite cracks of equal lengths in an infinite plane medium. The study is based on the solutions of the complex variable theory in plane elasticity theory. Multiparametric presentation of the stress filed near the crack tips in the infinite plate with two collinear cracks of finite lengths is obtained and analyzed for a full range of mixed mode loading from pure tension to pure shear. The method of analytical determination of coe ffi cients of the complete Williams asymptotic expansion of the stress field near the crack tip is presented. The influence of consideration of various numbers of terms of the series expansion on the stress distribution is discussed, and the significance of the multi-parameter fracture mechanics approach is emphasized. c � 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: Asymptotic analysis; Multiparametric presentation of the stress field near the crack tip, Williams series expansion 1. Introduction Characterization of crack tip stresses has been an area of active research for many decades [Willams (1957) – Lychak and Holyns’kyi (2016)]. M. Williams in his landmark paper [Willams (1957)] showed that the crack tip stress fields in an isotropic elastic material can be expressed as an infinite series where the leading term exhibits a r − 1 / 2 singularity and the second term is independent of r . Since then, the Williams series expansion appears to be the most favored analytical tool for the description of mechanical fields near crack-tips in planar domains and presents a general framework for the description of the stress field in the vicinity of the crack tip in an isotropic linear elastic medium: 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Complete Williams Asymptotic Expansion Near The Crack Tips of Collinear Cracks of Equal Lengths in an Infinite Plane Medium Larisa Stepanova a , Pavel Roslyakov b a Sam ra St te University, Ak d. Pavlo 1, Samara 443011, Russia b Samara State University, Akad. Pavlov 1, Samara 443011, Russia, JSC ”SRC Progress”, Zemetsa str. 18, Samara 443009 Abstract The study is aimed at analytical determination of coe ffi cients in crack tip stress expansions for two collinear finite cracks of equal lengths in an infinite plane medium. The study is based on the solutions of the complex variable theory in plane elasticity theory. Multiparametric presentation of the st ess filed near the crack tips in the nfinite plate with two collinear cracks of finite lengths is obtained and analyzed for a full range of mixed mode l ading from pure tension to pure shear. The method of analytical determination of coe ffi cients of the complete Williams asymptotic expansion of the stress field near the crack tip is presented. The influence of consideration of various numbers of terms of the series expansion on the stress distribution is discussed, and the significance of the multi-parameter fracture mechanics approach is emphasized. c � 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywo ds: Asymptotic analysis; Multi arametric pre e tation of th str ss field n ar the crack tip, Williams series expansion 1. Introduction Chara terization of crack tip st sses has een an area of active research for many decades [Willams (1957) – Lychak and Holyns’kyi (2016)]. M. Williams in his landmark paper [Willams (1957)] showed that the crack tip stress fields in an isotropic elastic material can be expressed as an infinite series where the leading term exhibits a r − 1 / 2 singularity and the second ter is independent of r . Since then, the Williams series expansion appears to be the most favored analytical tool for the description of mechanical fields near crack-tips in planar domains and presents a general framework for the description of the stress field in the vicinity of the crack tip in an isotropic linear elastic medium: 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/). P r view 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. Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation.

2 m = 1 2 m = 1

∞ k = −∞ ∞ k = −∞

m , i j k ( θ ) r m , i j k ( θ ) r

a m a m

k / 2 − 1 k / 2 − 1

σ i j ( r , θ ) = σ i j ( r , θ ) =

k f k f

(1) (1)

* Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt ∗ Stepanova L.V.. Tel.: + 7-842-334-5441 ; fax: + 7-846-334-5417. E-mail address: stepanovalv@samsu.ru ∗ Stepanova L.V.. Tel.: + 7-842-334-5441 ; fax: + 7-846-334-5417. E-mail address: stepanovalv@samsu.ru

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.2016.06.225 2452-3216 c � 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. 2452-3216 c � 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21.