PSI - Issue 1

ScienceDirect Procedia Structural Integrity 1 (2016) 150–157 Available online at www.sciencedirect.com Av ilable o line at ww.sciencedirect.com ScienceDirect Structural Integ ity Procedia 00 (2016) 00 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2016) 000 – 000

www.elsevier.com/locate/procedia

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. XV Portuguese Conference on Fracture, PCF 2016, 10-12 February 2016, Paço de Arcos, Portugal Mixed mode fatigue crack propagation in a railway wheel steel Daniel F. C. Peixoto a,b* , Paulo M.S.T. de Castro a a, b - Faculdade de Engenharia da Universidade d Porto, Rua Dr Roberto Frias, 4200-465 Porto, Portugal b -Institute of Science and Innovation in Mechanical and Industrial Engineering, Campus da FEUP, Rua Dr. Roberto Frias, 400 4200-465 Porto, Portugal Abstract The time-dependent stress state of railway wheels leads to fatigue crack propagation in mixed mode (I-II) conditions. In order to model a crack growth scenario in a railway wheel, mixed-mode I-II fatigue crack growth tests were performed on 9 mm thick Compact Tension Shear (CTS) specimens, taken from a Spanish AVE train wheel, using a servo-hydraulic MTS fatigue testing machine with 100 kN maximum load capacity. Fatigue crack growth rates and propagation direction (angle) of a crack subjected to mixed mode loading were measured. A finite element analysis was performed in order to obtain the K I and K II values for the tested lo ding angles. The crack propagation direction (angle) for the tested mixed mode loading conditions was experimentally measured and numerically calculated, and the obtained results were then compared in order to validate the used numerical techniques. The adopted methodologies, specime s’ di ensio and extraction p s tion, a d the obt i ed results are pres en ed and dis ussed in the present pape . © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: fatigue; mixed mode, railway wheel steel; cts specimen 1. Introduction A great number of the fatigue crack growth studies are commonly performed under mode-I loading conditions. However, single-mode loading rarely occurs in practice, and in many cases cracks are not normal to the maximum principal stress direction. Under mixed-mode loading conditions a crack will deviates from its original direction, Biner (2001). Several researchers indicate that rolling contact fatigue cracks are subjected to mixed mode I and II loading cycles, see e.g. Wong et al. (2000). Wheel shelling and rail squats are examples of defects originated in cracks that cause loss of large pieces of metal from wheel treads and rail head as a result of wheel-rail rolling contact c Copyright © 2015 The A thors. 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 PCF 2016. © 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. Tel.: 351 229578710; fax: +351 229537352. E-mail address: dpeixoto@inegi.up.pt

* Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016.

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Copyright © 2015 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 PCF 2016. 10.1016/j.prostr.2016.02.021