PSI - Issue 3

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com cienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structu al Integrity 3 (2017) 119–125 Available online at www.sciencedirect.com Sci nceD rect Structural Integrity Procedia 00 (2017) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2017) 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. Copyright © 2017 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 IGF Ex-Co. XXIV Italian Group of Fracture Conference, 1-3 March 2017, Urbino, Italy The effect o residual str ss on fatigue behavior of V-notched components: a review P. Ferro a , F. Berto b,* , S.M.J. Razavi b , M.R. Ayatollahi c a Department of Engineering and Management, University of Padova, Stradella S. Nicola, 3 I-36100 Vicenza, Italy. b Department of Mechanical and Industrial Engineering, Norwegian University of Science and Technology (NTNU), Richard Birkelands vei 2b, 7491, Trondheim, Norway. c Department of Me hanical Engineering, Iran Unive sity of Scie ce and Technology, Narmak, 16846, Tehran, Iran. Abstract Fatigue strength of mechanical components in the high cycle regime depends on the intensity of the residual stress field induced by non-homogeneous plastic deformation or the solidification of a local portion of material due to welding operations. In presence of geometric variations modelled as sharp V-notch angle, the residual stress distribution near the notch tip is singular and follows the same solution obtained by Williams in 1952 where the intensity of the asymptotic stress field is quantified by the notch stress int nsity factor (NSIF). However, the residual stress varies during fatigue l ading until a stationary value is reache . Numerical models were develop d for the calculation o th residual NSIFs and their variation under fatigue loading. Taking advantag from these m dels, new approaches were recently developed which are ble to predict the fatigue strength of pre stressed otched components. A revi w of such recent advances is describe in this work. © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific C mmittee of IGF Ex-Co. Keywords: high cycle fatigue; residual stress; V-notch, fatigue strength. XXIV Italian Group of Fracture Conference, 1-3 March 2017, Urbino, Italy The effect of residual stress on fatigue behavior of V-notched components: a review P. Ferro a , F. Berto b,* , S.M.J. Razavi b , M.R. Ayatollahi c a Department of Engineering and Management, University of Padova, Stradella S. Nicola, 3 I-36100 Vicenza, Italy. b Department of Mechanical and Industrial E gineering, Norwegian University f Science and Technology (NTNU), Rich rd Birkelands vei 2b, 7491, Trondheim, Norway. c Department of Mechanical Engineering, Iran University of Science nd Technology, Narmak, 16846, Tehran, Iran. Abstract Fatigue strength of mechanical components in the high cycle regime depends on the intensity of the residual stress field induced by non-homogeneous pl sti deformation or solidifi ation of a local p rtion of ma erial due to welding op rat ons. In presence f geom tric variations modelled as s arp V-not h a gle, the residual stress distribution near the notch ti is si gular and follows the same solution obtained by Williams in 1952 wher the int nsity of the asympto c str ss field is quantified by the notch stres intensity factor (NSIF). However, the residual stress vari s during fatigu loading until a tat onary value is reached. Numeric l model were dev loped for the calculation of the residual NSIFs and their variation under fatigue loading. Taking advant ge from thes models, n w approaches were r ce tly d veloped which are able to predict the str ngth f pre stressed notch d components. A review of such rec nt advances is described in this work. © 2017 The Author . Published by Elsevier B.V. Peer-review under espons bility of the Scientific Committee of IGF Ex-Co. Keywords: high cycle fatigu ; residual s ress; V-notch, fatigue strength.

1. Introduction

© 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. 1. Introduction

Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation. Staring from William’s work (1952), a great number of studies were carried out to evaluate the effect of local stress fields on the static and fatigue strength of mechanical components having a geometry variation modelled as sharp V-notch angle. Examples come from the fatigue strength of welded joints which is quantified in terms of Staring from William’s work (1952), a great number of studies were carried out to evaluate the effect of local stress f elds n the st tic and fatigue strength of mechanical compon nts having a ge metry variation modelled s harp V-notch angle. Examples come from the fatigue strength of welded joints which is qu ntified in t rms of

* Corresponding author. Tel.: +47-735-93831. E-mail address: filippo.berto@ntnu.no * Corresponding author. Tel.: +47-735-93831. E-mail address: filippo.berto@ntnu.no

* Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452-3216 © 2017 The Authors. Published by Elsevier B.V. Peer-review und r responsibil ty of the Scientific Committee of IGF Ex-Co. 2452-3216 © 2017 The Authors. Published by Elsevier B.V. Peer review under r sponsibility of the Scientific Committee of IGF Ex-Co.

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Copyright © 2017 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 IGF Ex-Co. 10.1016/j.prostr.2017.04.020