PSI - Issue 5

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com ienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structu al Integrity 5 (2017) 817–824 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 ( )

www.elsevier.com/locate/procedia . l i r. /l t / r i

www.elsevier.com/locate/procedia

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 Optimal notched specimen parameters for accurate fatigue critical distance determination C. Santus a , D. T ylor b , M. Benedetti c, * a Department of Civil and Industrial Engineering, University of Pisa, Pisa, Italy b Department of Mechanical & Manufacturing Engineering, Trinity College Dublin, Dublin, Ireland c Department of Industrial Engineering, University of Trento, Trento, Italy The critical distance value should theoretically be determined from the plain specimen fatigue limit and the threshold stress intensity factor, though usually ordinary notch geometries are considered. In this paper, we proposed an optimized sharp notch with the aims of simple and reliable manufacture and, more importantly, a local strong stress gradient able to minimize the sensitivity on the deduced critical distance value. A numerical procedure is proposed to find the critical distance from the fatigue strength of the notched specimen, by implementing the line m thod with simpl formulas based on dimensionless equations and specific co fficients derived from accurate FE analyses. A definition of the boundari s for a vali critical distance evaluation is also introduced and discussed. Finally, an application example is provided on a quenched and tempered steel also comparing the obtained critical distances with the threshold derived values. © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017. Keywords: Critical distance determination; Line method; Dimensionless analysis; Inversion problem; Q+T 42CrMo4 steel ad , a t t f i il I t i l i i , i it f i , i , It l b t nt f i l f t i i i , i it ll li , li , I l c t t f I t i l i i , i it f t , t , It l Abs iti l i t l l t ti ll t i t l i i ti li it t t l t i t it t , t ll i t t i i . t i , ti i t it t i i l li l t , i t tl , l l t t i t l t i i i t iti it t iti l i t l . i l i t i t iti l i t t ti t t t t , i l ti t li t it i l l i i l ti i i i i t i t l . i iti t i li iti l i t l ti i l i t i . i ll , li ti l i i t t l l i t t i iti al i t it t t l i l . t . lished by Elsevier . . i e i ilit t i ti i itt . : riti l i t t r i ti ; i t ; i i l l i ; I r i r l ; r t l © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017 Abstract

.

i

1. Introduction

© 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. The theory of critical distance is a widespread and reliable tool for assessing the strength of notched components in particular under fatigue loading (Taylor (2007), Taylor (2008)) and recently extended in many fatigue areas such as residual stress effects Benedetti et al. (2010) or even fretting fatigue Bertini and Santus (2015). iti l i t i i li l t l i t t t t t i ti l ti l i l , l tl t i ti i l t t tti t l. tti ti ti i t . t

* Corresponding author. Tel.: +39-046-1282457 E-mail address: matteo.benedetti@unitn.it i t r. l.: - - - il : tt . tti it .it 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.2017.07.057 * 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