PSI - Issue 3

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedirect.com ienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structural Integrity 3 (2017) 93–101 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2017) 000–000 il l li t . i i t. 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 Fatigue assessment of steel rollers using an energy based criterion F. Berto a,* , S.M.J. Razavi a , M.R. Ayatollahi b a Department of Mechanical and Industrial Engineering, Norwegian University of Science and Technology (NTNU), Richard Birkelands vei 2b, 7491, Trondheim, Norway. b Department of Mechanical Engineering, Iran University of Science and Technology, Narmak, 16846, Tehran, Iran. Abstract Weldments geometry with failures occurring at the weld toe or at the weld root cannot, by its nature, be precisely defined. Parameters such as bead shape and toe or root radius vary from joint to joint even in well-controlled manufacturing operations. The worst case configuration can be achieved by modelling as a sharp, zero radius, notch both the toe and the weld root. The intensity of asymptotic stress distributions obeying Williams’ solution are quantified by means of the Notch Stress Intensity Factors (NSIFs). For steel welded joints with failures originated from the weld roots, where the lack of penetration zone is treated as a crack-like notch, units for NSIFs are the same as conventional SIF used in LEFM. The different dimensionality of NSIFs for different notch opening angles does not allow a direct comparison of failures occurring at the weld toe or at the weld root. In order to overcome the problem related to the variability of the V-notch opening angle, a simple scalar quantity, i.e. the value of the strain energy density averaged in the structural volume surrounding the notch tip, has been introduced. This energy is given in closed form on the basis of the relevant NSIFs for modes I, II and III. The radius R C of the averaging zone is carefully identified with reference to conventional arc welding processes being equal to 0.28 mm for welded joints made of steel. The local-energy based criterion is applied here to steel welded rollers produced by Rulmeca subjected to prevailing mode I (with failures at the weld root). The aim of the paper is firstly to describe the employed methodology for the fatigue assessment and secondly to show the first synthesis of fatigue data by means of local SED for a specific geometry. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Be , b a t t f i l I t i l i i , i i it f i l ( ), i i l i , , i , . b t t f i l i i , I i it f i l , , , , I . l t t it il i t t l t t t l t t, it t , i l i . t s such as bead shape and toe or root radius vary from joint to joint even in well-controlled manufacturing operations. The worst case configuration ca i lli , i , t t t t t l t. i t it t ti t i t i ti i illi l ti ti i t t t t it t . t l l j i t it il i i t t l t , t l t ti i t t li t , it t ti l i . i t i i lit i t t i l t ll i t i il i t t l t t t l t. t t l l t t t i ilit t t i l , i l l tit , i. . t l t t i density averaged in the structural volume surrounding the notch tip, has been introduced. This energy is given in closed form o the basis of the relevant NSIFs for , . i t i i ll i ti i it t conventional arc welding processes i l t . l j i t t l. l l riterion is a li t t l l ll l j t t ili it il t t l t . i of the paper is firstly t i t l t l t ti t secondly to show the first synthesis of fatigue data by means of local SED for a specific geometry. t . li d y lsevi B.V. er- i i ilit t i ti i itt .

© 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: Welded Joints; Fatigue Strength; Notch Stress Intensity factor; Strain Energy Density; Elasticity. tr t ; t tr I t it f t r; tr i r it ; l ti it . : l i t ; ti

Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation.

* Corresponding author. Tel.: +47-735-93831. E-mail address: filippo.berto@ntnu.no * rr i t r. l.: - - . - il : fili . rt t .

* 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 IGF Ex-Co. 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 © 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.2017.04.013