PSI - Issue 5

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com ScienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structu al Integrity 5 (2017) 302–309 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2017) 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. 2nd International Conference on Structural Integrity, ICSI 2017, 4-7 September 2017, Funchal, Madeira, Portugal A Non-local Damage Model for Brittle Fracture in Metallic Structures with Stress Concentrators Anastasiia Kostina*, Alena Terekhina, Oleg Plekhov Institute of continuous media mechanics of the Ural branch of Russian academy of science, Ac.Koroleva st.,1, Perm, 614013, Russia This work is devoted to the development of the constitutive relations for the description of the defect evolution near the stress concentrators. A st uctural sensitive param t r is i troduced as an averaging of the symmetric l tensor characterizing unit defect with the Boltzmann-Gibbs distribution function. Constitutive equation for structural parameter was derived under an assumption of the local thermodynamic equilibrium. The application of the developed approach is illustrated by the numerical simulation of a nonlocal fracture process occurring in a Grade-2 titanium specimen with a stress concentrator under uniaxial tension condition. Nonlocal character of the fracture near the stress concentrator was shown and physical explanation of the critical distance theory as a length of a dissipative structure growing in blow-up mode kinetics in the defect ensemble was proposed. © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017. Keywords: mesoscopic defect; damage; critical distance theory; characteristic length; effective distance 1. Introduction Evolution of the structur l def cts is observed on all scale levels during the deformation process of metals. Therefore, to develop phenomenological model for evolution of defects it is necessary to define physical level for microstructure description and introduce variable involving integral structural changes at lower scale levels. In order to describe strain localization and failure, the developed model should take into account initiation of new structural defects, their coalescence and growth. I tit t f ti i i f t l f i f i , . l t., , , , i i i t t t l t t tit ti l ti t i ti t t l ti t t concentrators. A structural sensitive parameter is introduced as an averaging of the symmetrical tensor characterizing unit defect it t lt i i t i ti ti . tit ti ti t t l t i ti t l l t i ili i . li ti t l i ill t t t i l i l ti l l t i i tit i i it t t t i i l t i iti . l l t t t t t t t i l l ti t iti l i t t l t i i ti t t i i l i ti i t t l . t . li l i . . i i ilit t e S i ti i itt . : i f t; ; riti l i t t r ; r t ristic length; effective distance 1. Introduction ti t t t l t i ll l l l uring the deformation process of metals. Therefore, to develop phenomenological model for l ti t it i t i i l l l microst t i ti i t i l i l i i t l t t l t l l l l . t i t i l li ti il , t l l l take into account initiation of new structural defect , t i l t . © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017 © 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. Abstract

* Corresponding author. Tel.: +73422378312; fax: +73422378487. E-mail address: kostina@icmm.ru i t r. l.: ; f : . - il : ko ti i .r rr

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. 2452-3216  2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017 10.1016/j.prostr.2017.07.175 * Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452-3216 © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017. l i r . . i i ilit t i ti i itt . - t r . li