PSI - Issue 2_A

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 Struc ural Integrity 2 (2016) 3081–3089 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2016) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2016) 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. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Fractals and the lead crack airframe lifing framework Loris Molent a *, Andrea Spagnoli b , Andrea Carpinteri b , Rhys Jones c a Aerospace Division, Defence Science and Technology Group, 506 Lorimer Street, Fishermans Bend, Victoria, 3207, Australia. b Dept. Civil-Environmental Engineering & Architecture, University of Parma, Parco Area delle Scienze 181/A, Parma 43100, Italy. c Centre of Expertise for Structural Mechanics, Dept. Mechanical and Aerospace Engineering, Monash University, Victoria 3800, Australia. Abstract The physically short crack regime is primary region of interest in the design and sustainment of highly optimised metallic aircraft. The authors have previously shown that by characterising a fracture surface using fractals concept produces a crack growth model similar to that first proposed by Frost and Dugdale in 1958. This provides a scientific basis to the crack growth model. Further investigations revealed that for short cracks these models predict that crack growth is exponentially related to the applied load history. This observation has led to a practical aircraft lifing approach applicable to the short crack regime known as the lead crack framework. This paper summarises the fractality of metallic fracture surfaces, presents examples of the crack growth behaviour in complex structures, and summarises some useful crack growth tools. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: Fatigue crack growth; Fractal geometry; Short crack regime. 1. Introduction During the la t few decades the physically short crack regime in metals has received notable interest particularly in aerospace applications. What initially appeared to be anomalous fatigue behaviour when compared to that of long cracks is now referred to as the short-crack effect (Suresh and Ritchie, 1984). Such cracks are characterized by: (i) growth rates (da/dN) higher than what is derived by long-crack data for a given stress intensity range  K; (ii) often a decrease in da/dN with increasing  K; (iii) growth at  K values lower than the long-crack threshold; and (iv) a growth rate strongly dependent on the material microstructure. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Fractals and the lead crack airframe lifing framework Loris Molent a *, Andrea Spagnoli b , Andrea Carpinteri b , Rhys Jones c a Aerospace Division, Defence Science and Technology Group, 506 Lorimer Street, Fishermans Bend, Victoria, 3207, Australia. b Dept. Civil-Environmental Engine ring & Architecture, University of Parma, Parco Area delle Scie ze 181/A, Parma 43100, Italy. c Centre of Expertise for Structural Mecha ics, Dept. Mechanical and Aerospace Engineering, Monash U iversity, Victori 380 , Australia. Abstract The physically short crack regime is primary region of interest in the design and sustainment of highly optimised metallic aircraft. The authors have previously shown that by characterising a fracture surface using fractals concept produces a crack growth model similar to that first proposed by Frost and Dugdale in 1958. Thi provide a scien ific basis to the crack growth m del. Further investigations revealed that for short cracks these models predict that crack growth s exponentially related t the applied load history. This b er ation has led to a practi al aircraft lifing approac ppli able to e hort crack regime known as the l ad crack framework. This paper summarises the fractality of met llic fracture surfaces, pr ents examples of the crack growth beh viour in complex structur s, and summaris s some useful crack growth tool . © 2016 The Authors. Published by Elsevier B.V. Peer-review under espons bility of the Scientific Committee of ECF21. Keywords: Fatigue crack growth; Fractal geometry; Short crack regime. 1. Introduction During th last few decades the phy ic lly short crack egime in met ls has received notable inter st particularly in aerosp ce applicat ons. What initially appeared o be anomalous fatigue behaviour when compar d to tha of ong cracks is now referred to as the short-cr ck ff ct (Suresh and Ritchie, 1984). Such cracks are characterized by: (i) g owth rates (da/dN) higher t an what is derived by long-cr ck da a for a given stress inten ity range  K; (ii) often a decrease in da/dN with increasing  K; (iii) growth at  K values lower tha th long-crack threshold and (iv) growth rate strongly depe dent o the material microstructure. Copyright © 2016 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 ECF21. © 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.: +61 3 9626 7653. E-mail address: Loris.Molent@dsto.defence.gov.au. * Corresponding author. Tel.: +61 3 9626 7653. E-mail address: Loris.Molent@dsto.defence.gov.au.

* 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 ECF21. 2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer review under r sponsibility of the Scientific Committee of ECF21.

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Copyright © 2016 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 ECF21. 10.1016/j.prostr.2016.06.385