PSI - Issue 2_B

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com ScienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Struc ural Integrity 2 (2016) 2006–2013 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 The Th ory of Critical Distances to estimate static and dynamic strength of notched plain concrete Iason Pelekis a , Luca Susmel b, * a Department of Engineering, University of Cambridge, Trumpington Street, Cambridge, CB2 1PZ, United Kingdom b Department of Civil and Structural Engineering, the University of Sheffield, Mappin Street, Sheffield, S1 3JD, United Kingdom The Theory of Critical Distances (TCD) is a well-known design method allowing the strength of notched/cracked components to be estimated accurately by directly post-processing the entire linear-elastic stress fields damaging the material in the vicinity of the stress concentrators being designed. By taking full advantage of the TCD’s unique features, in the present study this powerful theory was reformulated to make it suitable for designing notched plain concrete against static and dynamic loading. The accuracy and reliability of the proposed reformulation of the TCD was checked against a set of experimental results generated by testing, under differen displacement rates, square section beams of plain concrete co taining notch s of fferent sharpness. This validation exercise has demonstrated that the proposed reformulation of the TCD is capable of accurat ly assessing the static a dynamic stre gth of notched unreinforced concrete, with the estimates falling within an error interval f ±20%. The level of accuracy that was obtained is certainly satisfactory, especially in light of the fact that static and dynamic strength was estimated without explicitly modelling the stress vs. strain dynamic behaviour of the concrete being tested. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: Concrete; notch; static strength; dynamic strength; Theory of Critical Distances 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy The Theory of Critical Distances to estimate static and dynamic strength of notched plain concrete Iason Pelekis a , Luca Susmel b, * a Department of Engineering, University of Cambridge, Trumpington Street, Cambridge, CB2 1PZ, United Kingdom b Department of Civil and Structural Engineering, the University of Sheffield, Mappin Street, Sheffield, S1 3JD, United Kingdom Abstract The Theory of Critical Distances (TCD) is a well-known design method allowing the strength of notched/cracked components to be stimated accurate y by dir ctly post-processing the entire linear-elastic stress fi lds damaging the material in the vicinity of the stress concent tors eing designed. By taking full advantage of the TCD’s unique features, the present study this powerful ory was reformulated to make it suitable for designing notched plain concret against static and dynamic loading. The accuracy nd reliability of he proposed reformulation of the TCD was checked against a set of experimental results generated by testing, under different displacement rates, square secti n b ams of plain concrete con aining notch s of diffe nt sharp ss. This validatio ex rcis has emonstrated that the proposed ref rmulation of the TCD is capable of accurately assessing he static and dynam c strength of notched un e nforced concr te, wit the es mates falling within an error interval of ±20%. Th level of accuracy that was btained is certainly satisfactory, especially in ligh of the fact that st tic and dynamic strength was stimat without explicitly modelling the s ress v . strain d namic behav our of the concre e being tested. © 2016 The Authors. Published by Elsevier B.V. Peer-review under espons bility of the Scientific Committee of ECF21. Keywords: Concrete; notch; static strength; dynamic strength; Theory of Critical Distances Copyright © 2016 The Authors. Published by Elsevier B.V. This i 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. Abstract

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. In situations of practical interest concrete structures have to be designed to withstand high rate of loading. In light of the importance of this complex structural engineering problem, since about the mid-1950s the scientific community has made a tremendous effort to understand and model the mechanical behaviour of concrete materials In situations of practical interest concrete structures have to be designed to withstand high rate of loading. In light of the imp rtance of this complex st uctura engin ering probl m, since about the mid-1950s the scientific community has made a tremendous effort o und rstand a d mode the me hanical be aviour of concrete mater als

* 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. * Corresponding author. Tel.: +44 (0) 114 222 5073; fax: +44 (0) 114 222 5700. E-mail address: l.susmel@sheffield.ac.uk 2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer review under r sponsibility of the Scientific Committee of ECF21. * Corresponding author. Tel.: +44 (0) 114 222 5073; fax: +44 (0) 114 222 5700. E-mail address: l.susmel@sheffield.ac.uk

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.2016.06.252