PSI - Issue 5

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedirect.com ienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structu al Integrity 5 (2017) 981–988 Available online at www.sciencedirect.com ScienceDirect 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. A GTN Failure Analysis of an AA6061-T6 Bi-Failure Specimen Behzad V. Farahani a,b, *, Rui Amaral a,b , Jorge Belinha b , Paulo J. Tavares a , Pedro Moreira a a INEGI, Institute of Science and Innovation in Mechanical and Industrial Engineering, Dr. Roberto Frias Street, 400, 4200-465, Porto, Portugal. b FEUP, Faculty of Engineering, University of Porto, Dr. Roberto Frias Street, 4200-465, Porto, Portugal. In the framework of non-linear fracture mechanics, this study concentrates on the failure prediction of a bi-failure specimen made of Aluminum alloy AA6061-T6 under tensile loading state. Thus, it firstly aims to experimentally evaluate the specimen force/displacement response over a uniaxial tensile test. The mechanical behavior of the material in addition to the modified geom trical proper ies of the test specime a e fully describ d. To obtain the xperimental d ta, an advanced optical technique, Digital Image Correlation (DIC), is used to evaluate the internal variables such as displacement in the presence of the failure phenomenon. To acquire the numerical assessment, the problem is modeled within the Finite Element (FE) formulation in ABAQUS© assuming a defined ductile damage criterion, Gurson – Tvergaard – Needleman (GTN), to attain the intended results. Successful numerical results obtained from FE were validated with experimental DIC data. Here, the failure evolution was perceived by DIC observations, allowing to explain the failure modes. Considering all acquired results, it can be concluded that the presented methodology is capable to predict the material damage and failure process. © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017. Keywords: Stress Triaxiality; Finite Element Method; Digital Image Correlation; Bi-failure; GTN Damage Criterio . 1. Introduction The accurate prediction of fracture in sheet metal forming process has become an important subject, bringing new challenges to the material characterization. During this process, the sheet metal can be subjected to large localized 2nd International Conference on Structural Integrity, ICSI 2017, 4-7 September 2017, Funchal, Madeira, Portugal A GTN Failure Analysis of an AA6061-T6 Bi-Failure Specimen Behzad V. Farahani a,b, *, Rui Amaral a,b , Jorge Belinha b , Paulo J. Tavares a , Pedro Moreira a a INEGI, Institute of Science and Innovation in Mechanical and Ind strial Engineering, Dr. Roberto Frias Street, 400, 4200-465, Porto, Portugal. b FEUP, Faculty of Engineering, University of Porto, Dr. Roberto Frias Street, 4200-465, Porto, Portugal. Abstract In the framework of non-linear fracture m chanics, this study concentrate on the failure p ediction of a bi-failur en mad of Aluminum alloy AA6061-T6 under loading stat . Thus, it firstly aims o experimentally evalua e spec m n force/displacement r ponse over a uniaxial tensi e test. Th mecha ical behav o of the m teri l in ddition to the modified geometrical prope ties f the test specimen are fully descr bed. To obt in the experiment l data, an advanc d optical echn q , Digital Image Correlation (DIC), is used to evaluate the internal variables such as displacement in the presence of the failure phen menon. To acquir th numerical assessment, the problem is modeled within the Finite Element (FE) formulation in ABAQUS© assum ng a defined ductile damage criterion, Gurson – Tvergaard – Needlem n (GTN), to ttain the inte ded results. Successful numerical results obtained from FE were validated with experimental DIC data. H re, the failure evolution was perceived by DIC observati ns, allowing explain the f ilure modes. Considering all acquired results, it can be concluded that the presented methodology is capable to predict the material damage and failure process. © 2017 The Autho s. Publ shed by Elsevier B.V. Peer-review under responsibility of the Scientific C mmittee of ICSI 2017. Keywords: Stress Triaxiality; Finite Ele ent Method; Digital Image Correlation; Bi-fail re; GTN Damage Criterion. 1. Introduction The accurate prediction of fracture in sheet metal forming process has become an important subject, bringing new challenges to the material characterization. During this process, the sheet metal can be subjected to large localized © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017 © 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. 2nd International Conference on Structural Integrity, ICSI 2017, 4-7 September 2017, Funchal, Madeira, Portugal Abstract

* Corresponding author. Tel.: +351 225082151. E-mail address: behzad.farahani@fe.up.pt * Correspon ing aut or. Tel.: +351 225082151. E-mail address: behzad.farahani@fe.up.pt

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. 2452-3216  2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017 10.1016/j.prostr.2017.07.147 * Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452 3216 © 2017 Th Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017. 2452-3216 © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017.