PSI- Issue 9

ScienceDirect Available online at www.sciencedirect.com Available o line at ww.sciencedire t.com ScienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structu al Integrity 9 (2018) 108–115 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 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. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. IGF Workshop “Fracture and Structural Integrity” A preliminary study on the potentialities of the Circular Semi-Ring test Ch. F. Markides, E. D. Pasiou, S. K. Kourkoulis* National Technical University of Athens, School of Applied Mathematical and Physical Sciences, Department of Mechanics, Laboratory for Testing and Materials, Theocaris Building, Zografou Campus, 157 73, Greece Abstract The potentialities of the Circular Semi-Ring test, as an alternative method for the indirect determination of the tensile strength of brittle materials, are discussed. The study is motivated by the fact that the outcomes of the familiar Brazilian-disc test are quite often criticized as providing erroneous results for the tensile strength, especially in case the origin of the fatal crack leading to the specimen’s fracture is not located at the disc’s center. The study described here focuses on the analytic determination of the dis placement field developed in a circular semi-ring, assuming that it is simultaneously subjected to both compression forces and bending moments. The analysis is implemented by taking advantage of the complex potentials technique as it was formulated by Muskhelishvili. Th solution derived s then val dated taking advantage of th ata for the respective displacem nt field obta ned experimentally with the aid of the Digital Image Correlation technique. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. Keywords: Circular Semi-Ring Test, Brazilian-Disc Test, Complex Potentials, Digital Image Correlation 1. Introduction The Brazilian-disc test, introduc d almost seventy five years earlier by Carneiro (1943) and Akazawa (1943), is nowadays considered as the most convenient substitute of the direct tension test, in case the tensile strength of very brittle rock-like materials is to be determined. Concerns about the validity of its results have been long ago expressed IGF Workshop “Fracture and Structural Integrity” A preliminary study on the potentialities of the Circular Semi-Ring test Ch. F. Markides, E. D. Pasiou, S. K. Kourkoulis* National Technical Univ rsity of At e s, Scho l of Applied Mathematical and Physical Sciences, Department of Mecha ics, Laboratory for Testing and Mat rials, Theocaris Building, Zografou Campus, 157 73, Greece Abstract The potentialities of the Circular Semi-Ring test, as an alternative method f r the indirect deter ination of the tensil strength of brittle materials, are discussed. The study is m tivated by the fact that the outcomes of the familiar Brazilian-disc test are quit often criticized as providing erroneous results for the tensile strength, especially in cas the origin of the fatal crack leading to the specim n’s fracture is not located at the disc’s center. The study described here focuses on th analytic determinati of the dis placement field developed in a circular semi-ring, assuming that it is simultaneously subjected to both compression forces and bending moments. The a alysis is implemented by taking advant ge of th complex potentials technique as it was formulated by Mu khelishvili. The solution derived is then validated taki g adva tage of t data for the respective displacement f eld obtai ed exp rimentally with the a d of th Digital Image Correlatio chnique. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Itali no Frattura (IGF) ExCo. Keywords: Circular Semi-Ring Test, Brazilian-Disc Test, Complex Potentials, Digital Image Correlation 1. Introduction The Brazilian-disc test, introduced almost seventy five years earlier by Carneiro (1943) and Akazawa (1943), is nowaday consid red as the most convenient substitute of the direct tension test, in case the tensile strength of very brittle rock-like materials is to be determined. Concerns about the validity of its results have been long ago expressed © 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.: +30 210 7721263; fax: +30 210 7721302. E-mail address: stakkour@central.ntua.gr * Correspon ing au hor. Tel.: +30 210 7721263; fax: +30 210 7721302. E-mail address: stakkour@central.ntua.gr

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. 2452-3216  2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. 10.1016/j.prostr.2018.06.018 * Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452 3216 © 2018 Th Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. 2452-3216 © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo.