PSI - Issue 2_A

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structu al Integrity 2 (2016) 832–839 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2016) 000–000 Available online at www.sciencedirect.com ScienceDirect 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 Charact rization f elastic-plastic-creep c ack-tip stress fields under load and displacement control Dong-Jun Kim a , Han-Sang Lee a , Jin-Ho Je a , Yun-Jae Kim a *, Robert A. Ainsworth b and Peter J Budden c a Department of Mechanical Engineering, Korea University, Anam-ro, Seongbuk-gu Seoul 02841, Korea b The University of Manchester, Manchester M13 9PL, UK c Assessment Technology, EDF Energy, Barnwood Gloucester GL4 3RS, UK Abstract This paper characterizes the elastic-plastic-creep crack-tip stress fields under load and displacement control. The stress field has been calculated from finite element (FE) transient creep analysis under each load control condition and displacement control condition. Varying the magnitude of initial step load is considered to investigate the influence of plasticity to creep. Both same stress exponent and different stress exponent in power-law creep and plasticity were considered. In the displacement control condition, elastic-follow-up factor is estimated by comparing FE results with existing formula. This paper proposes an equation to predict crack-tip stress fields under transient creep using a modification of the existing formula and verifies the proposed equation by comparing with FE results. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: Single-edge-cracked bend specimen;Elastic-plastic-creep;Crack-tip stress fields;Load control and displacement control condition 1. Introduction Structural integrity assessment of the plant structure under a high temperature operating conditions must take into account the creep phenomenon. The stress field around the crack-tip under the creep condition is a major factor in evaluating the life of the structure. Under the creep environment the crack-tip stress field and strain can change with 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Characterization of elastic-plastic-creep crack-tip stress fields under load and displacement control Dong-Jun Kim a , Han-Sang Lee a , Jin-Ho Je a , Yun-Jae Kim a *, Robert A. Ai sworth b and Peter J Budden c a Department of Mechanical Engineering, Korea University, Anam-ro, Seongbuk-gu Seoul 02841, Korea b The University f Manchester, Manchester M13 9PL, UK c Assessment Technology, EDF Energy, Barnwood Gloucester GL4 3RS, UK Abstract This paper characterizes the elastic-plastic-creep crack-tip stress fields under load and displacement control. The stress field has been c lculated from finit lement (FE) transient ree analysis under each load contro ondition and displacement control condition. Varying the magnitude of initial step load is considered to inv stigate the influen e of plasticity to cre p. Both same stress exponent and differe t str ss exponent in power-law cre p and plastici y w re considered. In the displac ment control condition, elastic-follow-up factor i estimated by c mparing FE results with ex sting formula. This paper proposes an quation to predict crack-tip stress fields under transient creep using a modification of the existing formula and verifies the proposed equation by comparing with FE results. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: Single-edge-cracked bend specimen;Elastic-plastic-creep;Crack-tip stress fields;Load control and displacement control condition 1. Introduction St uctural i t grity as essment of the plant structur under a high temperature operating conditions must take into account he creep phenomenon. The stress field aro nd th crack-tip und he cre p condition is a major f ctor in eval ating the life of the structure. Under the creep environment the crack-tip stress field and strain can change with Copyright © 2016 The Auth rs. Publis ed by Elsevier B.V. This is an open access article u der the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-n /4.0/). Peer-revi w und r 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 2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. 2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. * Corresponding author. Tel.: +82-2-3290-3372; fax: +82-2-929-1718. E-mail address: kimy0308@korea.ac.kr * Corresponding author. Tel.: +82-2-3290-3372; fax: +82-2-929-1718. E-mail address: kimy0308@korea.ac.kr

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.2016.06.107