PSI - Issue 1

ScienceDirect Procedia Structural Integrity 1 (2016) 042–049 Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com ScienceDirect Structural Integ ity Procedia 00 (2016) 00 – 000 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. XV Portuguese Conference on Fracture, PCF 2016, 10-12 February 2016, Paço de Arcos, Portugal Numerical evaluation of dissimilar cohesive models to predict the behavior of Double-Cantilever Beam specimens R.L. Fernandes a , R.D.S.G. Campilho a,b * a Departamento de Engenharia Mecânica, Instituto Superior de Engenharia do Porto, Instituto Politécnico do Porto, Rua Dr. António Bernardino de Almeida, 431, 4200-072 Porto, Portugal b INEGI – Pólo FEUP, Rua Dr. Roberto Frias, s/n, 4200-465 Porto, Portugal Abstract Adhesive bonding is a widely used joining method in industries such as aerospace, aeronautical and automotive because of specific advantages compared to the traditional fastening methods. Numerical approaches for the damage simulation of bonded joints based on fracture mechanics usually rely on Cohesive Zone Models (CZM). CZM suppose the characterization of the CZM laws in tension and shear, which are combined in mixed-mode criteria to predict the strength of bonded joints. This work evaluated the tensile fracture toughness ( G IC ) and CZM laws of bonded joints for two adhesives with distinct ductility. The Double-Cantilever Beam (DCB) test was used. The xperimental work consisted of the ten ile fracture characterization by the J -integral technique. A digital image correlation method was used for the eval ation of the tensile relative di placem nt (  n ) of the adhesive layer at the crack tip. F nite Element (FE) simulations were carried out to ass ss the accuracy of triangular, trapezoidal and linear-exponential CZM laws in predicting the experimenta behaviou of the DCB tests. As output of this w rk, information regarding the applicability of these CZM laws to each type of adhesive is provided, allowing th subsequent strength prediction of bonded joints. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: Cohesive zone modelling; J-integral; Finite element analysis; Crack growth, Adhesive joints. 1. Introduction Adhesive bonding is a widely used joining method in industries such as aerospace, aeronautical and automotive to attach structural components and as repair technique, because of specific advantages compared to the traditional XV Portuguese Conference on Fracture, PCF 2016, 10-12 February 2016, Paço de Arcos, Portugal Numerical evaluation of dissimilar cohesive models to predict the behavior of Double-Cantilever Beam specimens R.L. Fernandes a , R.D.S.G. Campilho a,b * a Departamento de Engenharia Mecânica, Instituto Superior de Engenharia do orto, Instituto Politécnico do Porto, Rua Dr. António Bernardino de Almeida, 431, 4200-072 Porto, Portugal b INEGI – Pólo FEUP, Rua Dr. Roberto Frias, s/n, 4200-465 Porto, Portugal Abstract Adhesive bonding is a wid ly used joining method in in ustries su h as aer space, aeronautic l and a tomotive because of specific advantages comp red to the traditional fastening methods. Numerical approache for th damage simulation of bonded joints based o fracture mechanics usually rely on Cohesive Zone Models (CZM). CZM suppose the characterization of the CZM laws in on and shear, which are combined in mixed-m de criteria to predict t str ngth of bo ded joints. This work evaluated the tensile frac ure toughness ( G IC ) and CZM laws f bonded joints for two adhesives with di tinc ductili y. The Double-Cantil ver Beam (DCB) test w s us d. The experim ntal work consisted h t n il f acture charact rizati n by the J -integral echniqu . A digital im ge corr lation method was used fo the evaluation of the tensil relative displacement (  n ) of the adhesive lay r at he crack tip. Finit Element (FE) simul tio s wer c rried out o assess the accuracy of triangular, trapezo dal and li ear-expo en ial CZM laws in pr dicting the experimental behaviour of the DCB tests. As output of thi work, information regarding the applicability of ese CZM laws to each type of adhesive is provided, allowing the subsequent strength prediction of bonded joints. © 2016 The Autho s. Publ shed by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: Cohesive zone modelling; J-integral; Finite element analysis; Crack growth, Adhesive joints. 1. Introduction Adhesive bonding is a widely used join ng method in industries such as aerospace, aeronautical and automotive to attach structural components and as repair technique, because of specific advantages compared to the traditional 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. © 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 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. * Corresponding author. Tel.: +351939526892; fax: +351228321159. E-mail address: raulcampilho@gmail.com * Corresponding author. Tel.: +351939526892; fax: +351228321159. E-mail address: raulcampilho@gmail.com

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.2016.02.007