PSI - Issue 2_B

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com Sci ceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Struc ural Integrity 2 (2016) 2148–2155 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2016) 000–000 il l li t . i i t. tr t r l I t rit r i ( )

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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 SIF Determination with Thermoelastic Stress Analysis Behzad V. Farahani a,b , Paulo J. Tavares a,* , P. M. G. P. Moreira a a INEGI, Institute of Science and Innovation in Mechanical and Industrial Engineering, Dr. Roberto Frias Street, 400, 4200-465, Porto, Portugal. b FEUP, Faculty of Engineering, University of Porto, Dr. Ro erto Frias Street, 4200-465, Porto, Portugal. Abstract This work is focused on the experimental determination of the stress intensity factor (SIF) using thermoelastic stress analysis (TSA) for a compact tension specimen during a fatigue crack growth test. A comparison of the stress field obtained with computational modelling, finite element method, against the experimental data obtained with the thermoelastic stress analysis under mode I loading in a fatigue test is presented. The stress field in front of the crack tip obtained with TSA, was used in William’s expansion, together with an overdetermined algorithm to calculate the SIF under mode I loading. The proposed methodology has a hybrid experimental-numerical nature where the stress intensity factor determination depends on a stress field obtained with an optical te hnique, TSA. The soundness of the experimentally obtained SIF solution was validated through finite element method computations. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: Stress intensity factor; Fatigue testing; Thermoelastic stress analysis; Finite element method. 1. Introduction The ability to tolerate a substantial amount of damage is a demand for contemporary structures, hence it has become increasingly important to enhance methodologies to anticipate failure in fatigue damaged components. Damage toleranc analyses can be carried out within linear elastic fracture mechanics (LEFM) concepts where the stress intensity factor (SIF) plays a substantial role. Fracture mechanics in conjunction with crack growth laws, i.e. Paris’ law, is commonly employed to nalyze and predict crack growth and fracture behavior of structural components. To ani a,b l a,* a a I I, I tit t f i I ti i ha ical and Industrial Engineering, Dr. Rob rto Frias Street, 400, 4200-465, t , t l. b , lt f i i , i it f t , . t i t t, - , t , t l. This work is focused on the experimental determination of the stress intensity factor (SIF) using thermoelastic stress analysis (TSA) for a compact tension specimen during a fatigue crack growth test. A comparison of the stress field obtained with t ti l lli , i it ele t t , i t t i t l t t i it t t l ti t l i l i i ti t t i t . t i l i t t ti t i it , i illi i , t t it t i l it t l l t t l i . t l i i t l i l t t t i t it t t i ti t i l t i it ti l t i , . t i t ll t i l ti li t t i it l t t t ti . t . li l i . . P review under responsibility o t Sci nti i itt . : tr i t it f t r; ti t ti ; r l ti tr l i ; i it l t t . . i The ilit t t l t t ti l t i t t t , it i i l i t t t t l i t ti i t il i ti t . t l e l i t it i li l ti t i t t t i t it t l t ti l l . t i i j ti it t l , i. . i l , i l l t l i t t t i t t l t . 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. © 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 225082151. E-mail address: ptavares@inegi.up.pt * rr i t r. l.: . - il : t r i i. . t

* 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. l i r . . i i ilit t i ti i itt . - t r . li

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.2016.06.269