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) 452–459 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 Finite element analysis of fretting contact for dissimilar and nonhomogeneous materials Yezd n M. Korkmaz a,b , Demirkan Cok r a,* a Dept. of Aerospace Engineering, Middle East Technical University, Ankara 06800, Turkey b Helicopter Group, Turkish Aerospace Industries (T I) Ankara 06980, Turkey Abstract Fretting problem arises in the case of relatively small sliding m tion between contacting surfaces leading to reduction in fatigue life of these parts significantly. The purpose of this study is to investigate the effects of fretting on the contact region in a cylindrical on flat contact configuration. In order to identify fretting contact, a finite element (FE) model was constructed by using commercial finite element package ABAQUS TM . Fretting contact is studied under two types of loading: tangential loading of the pad and axial bulk stress loading of the specimen. The numerical calculated stresses are compared with Mindlin analytical solution and Nowell and Hills analytical solution (which in ludes the ffect of bulk stress). In order to get a better estimate of fretting in real type structures suc as bolted joints and lug type structures, dissimilar materials in the contact region are th studied. For dissimilar mat rials, in the light of the conducted nu erical a alysis, Mindlin solution does not give reliable results in terms of shear traction distribution when compared to FE results. inally, the effect of non-homogeneity in materials is investigated by addition of circular voids. © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific C mmittee of ICSI 2017. Keywo ds: fretting; fatigue; finite element mo eling; ontact modeling; friction 1. Introduction When relative small sliding takes in place between two contacting surfaces, failure due to fretting can occur. This situation is observed in different kinds of parts, such as bolted joints and lug attachments of aircraft and helicopters. Waterhouse (1992) reported that bolted and riveted structures which are subjected to fluctuating loads are possible sources of fretting fatigue failures. Fatigue life of these parts may be significantly reduced due to fretting. To observe the effect of the fretting in the contact region, numerous work in literature can be found with both analytical and finite , oker a,* a t. f i i , i l t i l i it , 6 , b li t , i I t i ( AI) , tti l i i t l ti l ll li i ti t t ti l i t ti i ti li t t i i i tl . t i t i t i ti t t t tti t t t i i li i l l t t t i ti . t i ti tti t t, i it l t l t t i i l i it l t . tti t t i t i t t l i : t ti l l i t i l l t l i t i . i l l l t t it i li l ti l l ti ll ill l ti l l ti i i cl t t l t . t t tt ti t tti i l t t t h lt j i t l t t t , i i il t i l i t t t i t en t i . i i il te i l , i t li t t t m i l n l i , i li l ti t i li l lt i t t ti i t i ti t lt . Fi ll , t t it i t i l i i ti t iti i l i . 7 e Autho . li d lsevier B.V. Peer-review under responsibility of th i ti i itt . r : fr tti ; f ti ; fi it l t li ; t t li ; fri ti . i l ti ll li i t i l t t t ti , il t tti . i it ti i i i t i t , lt j i t l tt t i t li t . t t t t lt i t t t i j t t l t ti l i l sources of fretting fatigue failures. Fatigue li t t i i i tl t tti . t t t tti i t t t i , i lit t it t l ti l i it © 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.

* Corresponding author. E-mail address: coker@metu.edu.tr i t r. - il : r t . .tr 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.2017.07.196 * 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