PSI - Issue 1

Volume 1 • 201 6

ISSN 2452-3216

ELSEVIER

XV Portugese Conference on Fracture, PCF 2016, 10-12 February 2016, Paco de Arcos, Portugal

Guest Editors: Francesco I acoviello L uis R eis

Manuel Fonte Manuel Freitas Virg í nia I nfante

Available online al www.sciencedirect.com ScienceDirect

Welcome Message Welcome Message Welcome Message

ScienceDirect Procedia Structural Integrity 1 (2016) 001–001 Available online at www.sciencedirect.com Av ilable online at ww.sciencedire t.com ScienceDirect Structural Integ ity Procedia 00 (2016) 000 – 000 This book contains the abstracts of the presentations at the XV Portuguese Conference on Fracture. This series of conferences, are organized every two years by Portuguese researchers since 1987, in the sequence of the organization in 1984, of the Fifth European Conference on Fracture, in Lisbon, and are devoted to several aspects of fracture mechanics and fatigue of diverse materials, from metals to composites. In 2016 the conference is held at Escola Nautica Infante D. Henrique in Paço de Arcos, in the beautiful Estoril coast, from 10 th to 12 th February, co-organized jointly by Instituto Superior Técnico, under the auspices of the Fracture Division of the Sociedade Portuguesa de Materiais and ESIS, European Structural Integrity Society. For this conference, the organizing committee has decided to publish the papers under the new open access journal Structural Integrity Procedia, edited by Elsevier and available at ScienceDirect. We are proud to announce that this edition will be the first one of this new series of on-line journal. This will improve the visibility of the scientific work of portuguese researchers devoted to diverse aspects of fracture mechanics and fatigue of metals and composites. Special thanks are due to the invited speakers, Professors, Luca Susmel from the University of Sheffield, UK, Sofia T ixeira de Freitas from the Technical University of Delft, The Netherlands, Mário Vaz from Faculdade de Engenharia da Universidade do Porto, Portugal and Dr-Ing. Uwe Zerbst from BAM Federal Institute for Materials Research and Testing in Berlin, Germany. A total of 73 scientific works were submitted, on a wide range of topics, from Biomedical (8 papers), Composites (14 papers), Fatigue of metals (26 papers), Fracture (15 papers) and materials processing (10 papers). The organizing committee is grateful to the all authors by their participation allowing scientists and engineers to present and exchange new data and cutting edge deas during the presenta ions a d social events. The organizing committee is grateful to the support given by : Sociedade Portuguesa de Materiais, IDMEC – Instituto de Engenharia Mecân ca, Escola Superior Nautica Infante D. Henrique, IST - Instituto Superior Técnico, Caixa Geral de Depósitos, Instron, Câmara Municipal de Oeiras, Fundação para a Ciência e a Tecnologia and European Structural Integrity Society. This book contains the abstracts of the presentations at the XV Portuguese Conference on Fracture. This series of conferences, are organized every two years by Portuguese researchers since 1987, in the sequence of the organization in 1984, of the Fifth European Conference on Fracture, in Lisbon, and are devot d to s veral aspects of fracture mechanics and fatigue of diverse materials, from metals to composites. In 2 16 the conference is held at Escola Nautica Infante D. Henrique in Paço de Arcos, in the beautiful Estoril coast, from 10 th to 12 th February, co-organized jointly by Instituto Superior Técnico, under the auspices of the Fracture Division of the Sociedade Portuguesa de Materiais and ESIS, European Structural Integrity Society. For this conference, the organizing committee has decided to publish the papers under the new open access journal Structural Integrity Procedia, edited by Elsevier and available at ScienceDirect. We are proud to announce that this edition will be the first one of this new series of on-line journal. This will improve the visibility of the scientific work of portuguese researchers devoted to diverse aspects of fracture mechanics and fatigue of metals and composites. Special thanks are due to the invited speakers, Professors, Luca Susmel from the University of Sheffield, UK, Sofia Teixeira de Freitas from the Technical University of Delft, The Netherlands, Mário Vaz from Faculdade de Engenharia da Universidade do Porto, Portugal and Dr-Ing. Uwe Zerbst from BAM Federal Institute for Materials Research and Testing in Berlin, Germany. A total of 73 scientific works were submitted, on a wide range of topics, from Biomedical (8 papers), Composites (14 papers), Fatigue of metals (26 papers), Fracture (15 papers) and materi ls processing (10 papers). The organizing committee is grateful to the all authors by their participation allowing scientists and engineers to present and exchange new data and cutting edge ideas during the presentations and social events. The organizing committee is grateful to the support given by : Sociedade Portuguesa de Materiais, IDMEC – Instituto de Engenhari Mecânica, Esco a Superi r Nautica Infante D. Henrique, IST - Instituto Superior Técnico, Caixa Geral de Depósitos, Instron, Câmara Municipal de Oeiras, Fundação para a Ciência e a Tecnologia and European Structural Integrity Society. This book contains the abstracts of the presentations at the XV Portuguese Conference on Fracture. This series of conferences, are organized every two years by Portuguese researchers since 1987, in the sequence of the organization in 1984, of the Fifth European Conference on Fracture, in Lisbon, and are devoted to several aspects of fracture mechanics and fatigue of diverse materials, from metals to composites. In 2016 the conference is h ld at Escola Nautica Infante D. Henrique in Paço de Arcos, in the beautiful Estoril coast, from 10 th to 12 th February, co-organized jointly by Instituto Superior Técnico, under the auspices of the Fracture Division of the Sociedade Portuguesa de Materiais and ESIS, European Structural Integrity Society. For this conference, the organizing committee has decided to publish the papers under the new open access journal Structural Integrity Procedia, edited by Elsevier and available at ScienceDirect. We are proud to an ounce that this edition will be the first one of this new series of on-line journal. This will improve the visibility of the scientific work of portuguese researchers devoted to diverse aspects of fracture mechanics and fatigue of metals and composites. Special thanks are due to the invited speakers, Professors, Luca Susmel from the University of Sheffield, UK, Sofia Teixeira de Freitas from the Technical University of Delft, The Netherlands, Mário Vaz from Faculdade de Engenharia da Universida e do Porto, Portugal and Dr-Ing. Uwe Zerbst from BAM Federal Institute for Materials Research and Testing in Berlin, Germany. A total of 73 scientific works were submitted, on a wide range of topics, from Biomedical (8 papers), Composites (14 papers), Fatigue of metals (26 papers), Fracture (15 papers) and materials process ng (10 papers). The organizing committee is grateful to the all authors by their participation allowing scientists and engineers to present and exchange new data and cutting edge ideas during the presentations and social vents. The organizing committee is grateful to the support given by : Sociedade Portuguesa de Materiais, IDMEC – Instituto de Engenharia Mecânica, Escola Superior Nautica Infant D. Henrique, IST - Instituto Superior Técnico, Caixa Geral de Depósitos, Instron, Câmara Municipal de Oeiras, Fundação para a Ciência e a Tecnologia and European Structural Integrity Society. Welcome Message This book contains the abstracts of the presentations at the XV Portugues Conference on Fracture. This series of conferenc s, are organized very two years by Portuguese researchers since 1987, in the sequence of the rganization in 1984, of the Fifth Europ an Conference on Fracture, in Lisbon, and are devoted to several aspects of fracture m chanics and fatigue of dive se materials, from metals to composites. In 2016 the conference is held at Escola Nautica Infante D. Henrique in Paço de Arcos, in the beautiful Estoril coast, from 10 th to 12 th February, co-organiz jointly by Instituto Superior Técnico, under the auspices of the Fracture Division of the Sociedade Portuguesa de Materiais and ESIS, European Structural Integrity Society. For this conference, the organizing committee has decided to publish the papers under the new open access journal Structural Integri y Procedia, edi ed by Elsevier and available at Sci nceDirect. We are proud to announce that this edition will be the first ne of this new series of on-line journal. This will improve the visibility of the scientific work of portuguese researchers devoted to diverse aspects of fracture mechanics and fatigue of metals and composites. Special thanks re due to the invited s eakers, Professors, Luca Susmel from the University of Sheffield, UK, Sofia Teixeira de Fr itas from the Technical U iversi y of Delft, The Netherlands, Mário Vaz from Faculdade de Engenharia da Universidade do Porto, Portugal and Dr-Ing. Uwe Zerbst from BAM Federal Institute for Materials Research and Testing in Berlin, Germany. A total of 73 scientific works were submitted, on a wide range of topics, from Biomedical (8 papers), Composites ( 4 a ers), Fatigue of metals (26 papers), Fracture (15 papers) and materials processing (10 papers). The organizing committee is grateful to the all authors by their participation allowing scientists and engineers to present and exchange new data and cutting edge ideas during the presentations and social events. The organizing committee is grateful to the support given by : Sociedade Portugues de Mat riais, IDMEC – Instituto de Engenharia Mecânica, Escola Superior Nautica Infante D. Henrique, IST - Instituto Superior Técnico, Caixa Geral de Depósitos, Instron, Câmara Municipal de O iras, Fundação para a Ciência e a Tecnologia and European Structural Integrity Society. Welcome Message This book contains the abstracts of the present tions at the XV Portuguese Conference on r ctur . This series of conferences, are organized every tw y ars by Portuguese researchers since 1987, in the sequence of the organization in 1984, of the Fif h European Confer nce on Fracture, in Lisbon, and are devoted to several aspects of fracture mechanics and fatigue of diverse materials, from metals to compo ites. In 2016 the co fe ence is held at Esc la Nautica Infante D. Henriqu in Paço de Arcos, in the b autiful Estoril coast, from 10 th to 12 th February, co-organized jointly by Ins ituto Superior Técnico, under the auspic s of the Fracture Division of the Sociedade Po tuguesa de Materiais and ESIS, Eur pean Structural Integrity Society. Fo this c fer nce, the organizing commi tee has decided to publish the papers under the new open acc ss journal Structural Integrity Proc dia, edited by Elsevier and available at ScienceDirect. We are proud to announce that this edition will be the first one of this new series of on-line journal. This will improve the visibility of the scientific work of portuguese researchers devoted to d verse aspects f fracture me hanics and fatigue of metals and composites. Special thanks are du to the nvited speak rs, Professors, Luca Susmel from the University of Sheffield, UK, Sofia Teixei a de Fr itas from the Technical U iversity of Delft, The N therlands, Mário Vaz from Faculdade de Engenharia da Universidade do Porto, Portugal and Dr-Ing. Uwe Zerbst from BAM Federal Institute for Material Research and Tes ing in Berlin, Germany. A total of 73 sc e tific ork were ubmitted, on a wide range of topics, from Biomedical (8 papers), Composi es (14 papers), Fatigue of metals (26 papers), Fracture (15 pap rs) and materials processing (10 papers). The organizing committee is grateful to the all authors by their participation allowing sci ntists and e gineers to present and exch nge new data and cutting dge idea d ring th presentati ns nd soci l events. The organizing committee is grateful to the support given by : Sociedade Portugues de Materiais, IDMEC – Instituto de Eng nharia Mecânica, Escola Superior Nautica Infante D. Henrique, IST - Instituto Superior Técnico, Caixa Geral de Depósitos, Instron, Câmara Municipal de Oeiras, Fundação para a Ciência e a Tecnologia and European Structural Integrity Society. Welcome Message This book co tains the abstracts of the presentations at the XV Portuguese Conference on r cture. This series of conferences, are orga ized every two years by Portuguese researchers since 1987, in the sequence of the rganization in 1984, of the Fifth European Conference on racture, i Lisbon, and are devoted to several aspects of fracture mechanics and fatigue of diverse materials, from metals to composites. In 2016 the conference is held t Escola Nautica Infante D. Henrique in Paço de Arcos, in the beautiful Estoril coast, from 10 th to 12 th February, co-organized jointly by Instituto Superior Técnico, under the auspices of the Fracture Division of the Sociedade Portuguesa de Materiais and ESIS, European Structural Integrity Society. For this conference, the orga izing committee has decided to publish the papers under the new open access journal Structural Integrity Procedia, edited by El evier and available at ScienceDirect. We are proud to announce that this edition will be the first one of this new series of on-line journal. This will improve the visibility of the scientific work of portuguese researchers devoted to diverse aspects of fracture mechanics and fatigue of metals and composites. Special thanks are due to the invited speakers, Professors, Luca Susmel from the University of Sheffield, UK, Sofia Teixeira de Fr itas from the Technical U iversity of Delft, The Netherlands, Mário Vaz from Faculdade de Engenh ria da U iversidade do Porto, Portugal and Dr-Ing. Uwe Zerbst from BAM Federal Institute for Materials Research and Testing in Berlin, Germany. A total of 73 scientific work wer submitt d, on a wide range of topics, from Biomedical (8 paper ), Composites (14 paper ), Fatigu of metals (26 papers), Fracture (15 papers) and materials processing (10 papers). The organizing committe is grateful to the all authors by their participation allowing scientists and engineers to present and exchange new data and cutting edge ideas during the presentations and social events. The organizing committee is grat ful to t e support given by : Sociedade Portugues de Materiais, IDMEC – Instituto de Eng nharia Mecânica, Escola Superior Nautica Infante D. Henrique, IST - Instituto Superior Técnico, Caixa Geral de Depósitos, Instron, Câmara Municipal de Oeiras, Fundação para a Ciência e a Tecnologia and European Structural Integrity Society. Welcome Message This book contains the abstracts of the present tions at he XV Portuguese Conferenc on Fracture. This series of conferences, are orga zed every w y ars by Portuguese r searchers since 1987, in the seq ence of the organiz tion in 1984, of the Fifth European Confer nce on Fracture, in Lisbon, and are devoted to several aspects of fracture mechanics and fatigue of diverse materials, from metals to composites. In 2016 the conference is held at Esc la Nautica Infante D. Henrique in Paç e Arcos, in the beautiful Estoril coast, from 10 th to 12 th F bruary, co-organized jointly by Instituto Superior Técnico, under the auspices of the Fracture Division of the Sociedade Portuguesa de Materiais and ESIS, European Structural Integrity Society. F r thi c fer nce, the organizing committee has decided to publish the papers under the new open acc ss journal Structural Integrity Proc dia, edited by Elsevier and available at ScienceDirect. We are proud to announce that this edition will be the first one of this new series of on-line journal. This will improve the visibility of the scientific work of portuguese researchers devoted to diverse aspects of fracture mechanics and fatigue f metals and composites. Special thanks are du to the invited speakers, Professors, Luca Susmel from the University of Sheffield, UK, Sofia Teixeira de Freitas from the Technical University of Delft, The Netherlands, Mário Vaz from Faculdade de Engenharia da Universidade do Porto, Portugal and Dr-Ing. Uwe Zerbst from BAM Federal Institute for Materials Research and Testing in Berlin, Germany. A total of 73 scie tific orks were submitted, on a wide range of topics, from Biomedical (8 papers), Composite (14 pap rs), Fatigue of metals (26 papers), Fracture (15 papers) and materials processing (10 papers). The organizing committee is grateful to the all authors by their participation allowing scientists and engineers to present and exchange new data and cutting edge ideas during the presentations and social events. The organizing committee is grateful to the support given by : Sociedade Portuguesa de Materiais, IDMEC – Instituto de Engenharia Mecânica, Escola Superior Nautica Infante D. Henrique, IST - Instituto Superior Técnico, Caixa Geral de Depósitos, Instron, Câmara Municipal de Oeiras, Fundação para a Ciência e a Tecnologia and European Structural Integrity Society. Welcome M ssage This book contains the abstracts of the presentations at the XV Portuguese Conference on Fracture. This series of conferences, are organized every two years by Portuguese researchers since 1987, in the sequence of the organization in 1984, of the Fifth European Conference on Fracture, i Lisbon, and are devoted to several aspects of fracture m chanics and fatigue of diverse materials, from metals to composi es. In 2016 the conferenc is hel t Esco a Nautica Infa t D. Henrique in Paço de Arcos, i the beautiful Estoril coast, from 10 th to 12 th F bruary, c -organized jointly by Instituto Supe ior Técnico, under the auspices of the Fracture Division of the Sociedade Po uguesa de Materiais and ESIS, European Structural Integrity Society. For this conference, the organizing committee has decided to publish the papers under the n w open access journal Structural Int grity Proced a, edite by El e ier and vailable at cienceDirect. We ar proud to announce that this ed tion w ll be the first one of this ew series of on-line journal. This will improve the visibility of the scientific work of portuguese researchers devoted to diverse aspects f fracture mechanics and fatigue f metals and composites. Special thanks are due to the invited sp akers, Professors, Luca Susmel from th University of Sheffield, UK, Sofia Teixeir de Freitas f om the Technical Un ve sity of Delft, The N therlands, Mário Vaz from Faculdade de E genh ria da Universidad do Porto, Portugal and Dr-Ing. Uwe Zerbst from BAM Federal Institute for Materials Research and Tes ing in Berlin, Germany. A total of 73 scientific works wer submitted, on a wid range of topics, from Biomedical (8 papers), Composites (14 papers), Fatigue of metals (26 pap rs), Fracture (15 papers) and materials processing (10 papers). The rga izin committe is grat ful to the all authors by their participation allowing sc ntists and engineers to present and exch nge new data and cutting edge idea d ring the presentations and social events. The organizing committee is grateful to the support given by : Sociedade Portuguesa de Materiais, IDMEC – Instituto de Engenharia Mecânica, Escola Superior Nautica Infante D. Henrique, IST - Instituto Superior Técnico, Caixa Geral de Depósitos, Instron, Câmara Municipal de Oeiras, Fundação para a Ciência e a Tecnologia and European Structural Integrity Society. Welcome Message This book co t ins the abstracts of the presentations at the XV Portuguese Conference on r e. This series of conferences, are organized very two years by Portuguese researchers since 1987, in the sequence of he rganization in 1984, of the Fifth European Conference o Fracture, in Lisbon, and are devoted to sever l aspects of fracture mecha ics and fatigue of diverse materials, from metals to composites. In 2016 the conference is held at Escola Nautica Infante D. Henrique in Paço de Arcos, in the beautiful Estoril coast, from 10 th to 12 th F bruary, co-organized jointly by Instituto Superior Técnico, under the auspices of the Fracture Division of the Sociedade Portuguesa de Materiais and ESIS, European Structural Integrity Society. For this conference, the rganizing commi tee has decided to publish the papers under the new pen access jo rnal Structural Integrity Procedia, edi ed by Elsevier and vailable at ScienceDirect. We are proud to announce that this edition will be the first one of this new series of on-line journal. This will improve the visibility of the scientific work of portuguese researchers devot d to diverse aspects of fracture mechanics and fatigue of metals and composites. Special thanks are due to the invit d speakers, Professors, Luca Susmel from the University of Sheffield, UK, Sofia Teixeira de Fr itas from the Technical U iversi y of Delft, The Netherlands, Mário Vaz from Faculdade de Engenharia da Universidade do Porto, Portugal and Dr-Ing. Uwe Zerbst from BAM Federal Institute for aterials Research and Testing in Berlin, Germany. A total of 73 scientific works were submitted, on a wide ra ge of topic , from Biomedical (8 papers), Composites (14 papers), Fatigue of metals (26 ap rs), Fracture (15 papers) and materials processing (10 papers). The organizi g c mmitt e is grateful to the all authors by their participation allowing scientists and engineers to present and exchange new data and cutting edge ideas during the presentations and social events. The organizing commi tee is grateful to the support giv n by : Sociedade Portugues de Mat r ai IDMEC – Instituto de Eng nharia Mecânica, sc la Superior Nautica Infante D. Henrique, IST - Instituto Superior Técnico, Caixa Geral de Depósitos, Instron, Câmara Municipal de Oeiras, Fundação para a Ciência e a Tecnologia and European Structural Integrity Society. Welcome Message This book contains the abstracts of the prese tations at the XV Portuguese Conf renc on Fractur . This series of conferences, are organized every two years by Portuguese researchers sin e 1987, in the sequ nc of the organization in 1984, o the Fifth European Confer nce on Fracture, i Lisbon, and are devoted to several aspects f fractur m chanics nd fatigue of div rs mat rials, from metals to composites. In 2016 the conferenc is held at Escola Nautica Infante D. He r que i Paço de Arcos, in the beautiful Estoril coast, from 10 th to 12 th February, co-organiz d join ly by Instituto Superior Técnico, under the auspi es of the F acture Division of the Sociedade Po tugues de Materiais and ESIS, European Str ctural Integrity Soci ty. For this c nf re e, the o ganizing comm tee has decide to pub ish the papers und r he new pen a cess journal Structural Integrity Procedia, edited by Elsevie and vailable at ScienceDirect. We are proud to an ounce that this edition will be the first one of this w s rie of on-line journal. Thi will improve the visibility of the scientific work of portuguese researchers devoted to iverse aspects of fracture mech nics and fatigue of metals and composites. p cial thanks are due to the invited peakers, Professors, Luca Susmel from the University of Sheffield, UK, S fia Teixeira de Freitas from the T chnical University of Delft, The Netherlands, Már o Vaz fr m Faculdade de Engenh r a da Universidad do Porto, Portugal nd Dr-Ing. Uwe Zerbst from BAM Federal In titute for Ma rials Research and Testing in Berlin, Germany. A total of 73 scientific works were submitted, on a wide range of topic , from Biomedical (8 papers), Composites 4 , Fatigue of metals (26 pap r ), Fracture (15 paper ) and m ter l processing (10 papers). The orga izi g committee is grateful to th all authors by their participation allowing scientists nd engineers to pr s nt and exchange new d ta a d cutting edge ideas during the present tions and social events. The organizing commit ee is grateful to the support given by : Sociedade Portuguesa de Materiais DMEC – Instituto de Enge haria Mecânic , Escola Superior Nautica Infante D. Henrique IST - Instituto Superior Técnico, Caixa Geral de De ósitos, Inst on, Câmara Municipal de Oeiras, Fundação para a Ciência e a Tecnologia and European Structural Integrity Society. Welco i k t i t tr t f t r t ti ns at the XV Portuguese Conferenc on ra t r . i seri s of confer nces, are organized every two years by Portugue e res archers since 1987, in the sequence of t rganizati i 84, of the Fift r pean Conference on Fracture, in Lisbon, a d re de t t er l p t of fracture mechanics and fatigue of diver e materials, from met ls to compos es. In 2016 th f r e i l t l Na tica Infante D. Henrique in Paço d A cos, in the beautiful Estoril coast, from 10 th to 1 th r r , c -or i j i tl I stitut ri r cnico, under the auspices of the Fract re Division of th i t t ri i I , r tr t ral Integrity Soci ty. For this conference, the o ganizing committee has decided to publish th pap rs n r t e n ccess jo r l Structural Integrity Procedia, e ite by Els i r ailabl t Sci nceDirect. W are proud to ann unce that this dition will be the first one of this new s ri s f -li j r l. is ill i r t isi ilit f t i tifi rk f rt se r r r t t i erse aspects of fracture mechanics nd fatigue of metals and compos tes. Sp ci l thanks are due to the nvited speak rs, Professo s, Luca Susmel from th U i r it f Sheffiel , UK, Sofia Teixeira de Fre t s fr m the Technical U iv r it f lft, t rl , Mári Vaz from Faculdad de Engenharia da Universi ade do P rt , Portugal and Dr-Ing. Uwe Z rbst fro B ral I t tute f r Material earch an tin in rli , r . A total of 73 scien fic wor r b itt , i r f to i , fr i i l (8 p rs), Composites (14 p pe s), Fati u f t l ( rs), r t re ( r ) m t ri l r i ( r ). r a izi itt i r t f l t t ll t r thei parti i ti ll i i ti t i r t r t t tti i ri g the re t ti i l t . T r i i itt i r t f l t t rt iv : i rt M t ri i , I I tit t ri i a, l uperior ti a Infante D. Henrique, I - I tituto Superior Técnico, Caixa Geral de Depósitos, Instron, Câmara Municipal de O ir , r i i cnol i d European Str tural Integrity Soci t . www.elsevier.com/locate/procedia 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. © 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. Lisbon, February 2016 Lisbon, February 2016 Lisbon, February 2016 Lisbon, February 2016 Luís Reis Luís Reis Luís Reis Luís Reis Manuel Fonte Manuel Fonte Lisbon, February 2016

* Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt Manuel de Freitas Manuel e Freitas Manuel Fonte a el Fonte Lisbon, February 2016 Lisbon, February 2016 Lisbon, February 2016 Lisbon, February 2016 Virgínia Infante Manuel de Freitas Luís Reis

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.2016.02.001 Virgínia Infante Virgínia Infante Manuel de Freitas Virgínia Infante Manuel Fonte Manuel de Freitas Luís Reis Manuel Fonte Luís Reis Luís Reis Lisbon, February 2016 Li b , ebruary 2016

Virgínia Infante Manuel de Freitas Manuel Fonte Manuel de Freitas anuel Fonte Manuel de Freitas Luís Reis Manuel Fonte Luís R is Font Luís Reis a el t Virgínia Infante

ScienceDirect Procedia Structural Integrity 1 (2016) 226–233 Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com ScienceDirect Structural Integ ity Procedia 00 (2016) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 il l li t . i i t. tr t r l I t rit r i ( )

www.elsevier.com/locate/procedia . l i r. /l t / r i

www.elsevier.com/locate/procedia

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 A meshless method in the non-local constitutive damage models Behzad V. Farahani a , F.M. Andrade Pires a , P.M.G.P. Moreira b , J. Belinha a,b, * a Faculty of Engineering , University of Porto, Rua Dr.Roberto Frias, S/N, 4200-465 Porto - Portugal b Institute of Mechanical Engineering and Industrial Management, Rua Dr.Roberto Frias, S/N, 4200-465 Porto - Portugal Abstract The radial point interpolation method (RPIM), as an advanced dis retization approach, i used to analyze concrete structures assuming a non-linear continuum damage model. The theoretical basis of the material, damage characteristics and the computational procedure are presented. The elastic model is extended with a non-local damage formulation for compressive stress state from the Helmholtz free energy function in relation to the damage energy release. The predictive ability of the non local model will be compared with the local solution, which is inappropriate whenever strong strain softening is encountered. Due to the presence of damage, the Newton-Raphson non-linear algorithm is employed, creating a fictitious pseudo-time stepping scheme. The performance of the proposed model is verified with an experimental benchmark available in the literature. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: Non-local Damage Model; Radial Point Interpolation Method; Return-mapping Algorthim; Meshless method; Concerrte Stuctures. 1. Introduction Several demanding fields in computational mechanics are appropriate to study the non-linear standard damage solution of brittle materials using finite element method (FEM) formulations [See Oliver et al. (1990); Cervera et al. (1995); Cervera et al. (1996); Faria et al. (1998); Lee & Fenves (2001); He et al. (2006); Yu et al. (2008) and Voyiadjis and Taqieddin (2009)]. Researchers investigated the continuum damage mechanics theory varying , , a lt f i i , i it f t , . t i , / , - t - t l b I tit t f i l i i I t i l t, . t i , / , - t - t l i l i t i l ti t , i ti ti , t l t t t i li ti l. t ti l i t t i l, t i ti t t ti l t . l ti l i t it l l l ti i t t t t l lt ti i l ti t t l . i ti ilit t l l l ill it t l l l ti , i i i i t t t i t i i t . t t , t t li l it i l , creating a fictitious p ti t i . performance of the proposed model is verified with an experimental benchmark available in the literature. 16 h Authors. li l i . . Peer-review under responsi ility t i ti i itt . : -l l l; i l i t I t r l ti t ; t r - i l rt i ; l t ; rrt t t r . . i l i i l i t ti l i i t t t t li t l ti ittl t i l i i it l t t l ti li t l. ; t l. ; t l. ; i t l. ; ; t l. ; t l. Voyiadjis d Taqieddin (2009)]. Res i ti t the continuum i t i Copyright © 2015 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.o g/licenses/by-nc-nd/4.0/). Peer-review under sponsibility of the Sci ntific Committ e 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. l i r . . i i ilit t i ti i itt . * Corresponding author. Tel.: +351 225081491/ 1571, Fax: +351 225081538. E-mail address: jorge.belinha@fe.up.pt i t r. l.: / , : . - il : j r . li f . . t - t r . li rr

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.2016.02.031

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different variables in order to fit the experimental solutions [Tao and Phillips (2005) and Wu et al. (2006)]. Basically, there exist several principal stress components indicating the material degradation within the constitutive model [Lee and Fenves (2001)]. Furthermore, the return-mapping algorithm is applicable to achieve the non-linear damage solution for each pseudo-time stepping scheme [Simo et al. (1986) and Lee et al. (2001)]. Currently, the foregoing algorithm is based on the decomposition of the trial stress [Simo (1992)]. The present study employs the developed form of the return-mapping algorithm for a rate-independent damage model to analyse concrete structures, such as three-point-bending beams, considering an advanced discretization technique: the Radial Point Interpolation Meshless Method (RPIM) [J. Belinha (2014) and Vasheghani Farahani et al. (2015)]. Meshless methods are capable to analyse complex structural models; the high-order continuity of the constructed test functions permits to achieve smoother internal variables, such as the strain/stress fields; they can be efficiently used to solve large deformation problems and; they permits to insert locally more nodes where mesh refinement is required, without any extra computational cost [J. Belinha (2014)]. The local damage constitutive law has the potential to solve different problems. For instance, the creep-related fields as primarily established by Kachanov (1986). Basically, the damage mechanics theory is applicable to analyse distinct material responses including brittle and ductile behaviours [Krajcinovic and Fonseka (1981); Krajcinovic and Fonseka (1983); Resende and Martin (1984); Oliver et al. (1990) ; Cervera et al. (1995); Cervera et al. (1996); Faria et al. (1998); Voyiadjis and Taqieddin (2009)]. These mentioned works have been substantially focused on developement of the local damage principles. As an illustration, the rate – independent damage formulation for local models has been adopted by Crisfield (1996) and later on improved by Cervera et al. (1996) and Faria et al. (1998). However, the local damage models are inappropriate whenever strong strain softening is encountered. Due to this matter, the governing differential relationships might lose ellipticity. In the numerical point of view, this situation appears itself by spurious mesh sensitivity of finite element computations as the mesh is refined the strain localizes into a narrow band whose width depends on the element size and tends to zero. Thus, the corresponding response of load-displacement always experiences snapback for a sufficiently fine mesh, and the total energy dissipated by fracture converges to zero [Jirásek (1998)]. In FEM studies, the most trustful approach to tackle the aforementioned disturbance, is to regulate the post-peak slope of the stress-strain curve as a function of the element size. The concept of non-local averaging is sufficient for the localization limiters applied on any kind of constitutive model. In fact, the idea of non-local continuum models was firstly introduced by Eringen (1966) and later on developed for the strain-softening materials by Bazant (1984). Afterwards, Pijaudier-Cabot et al. (1987) proposed an improvement, establishing the non-local damage theory. Its early extension was developed into various approaches of non-local models for damage and fracture mechanics by Jirásek (1998). Furthermore, non-local plasticity corresponds to finite element method was conducted by Strömberg and Ristinmaa (1996). In meshless methods, the resolution approach for non-local damage model is precisely different due to its nature. The scenario is to use a weight function associated to each integration point. Thus, first, consider a specific integration point possessing a definite damage value. Then, its damage value is distributed to other neighbor points respecting the corresponding weights from the weight function, leading to localize damage. At the end, it is possible to obtain the non-local damage value on the certain integration points. The non-local damage algorithm is described with detail next section. 2. Solid Mechanics and Damage Formulations In this work, the plane stress deformation theory in 2D case is assumed. According to Hooke ’s law with regard to c as the material constitutive matrix in plane stress state, it is possible to determine the stress field as follows: = = [ 0 0 ] { ( , ) ( , ) } = { + } = { } , = = (1 + ) (1 − ) [ 1 0 1 0 0 0 1 − 2 ] { } = { } (1)

228 Behzad V. Farahani et al. / Procedia Structural Integrity 1 (2016) 226–233 Behzad V. Farahani et al./ Structural Integrity Procedia 00 (2016) 000 – 000 3 The discrete equation system is obtained using the Galerkin weak form. The Lagrangian functional is defined by = − + . Being, T and U the kinetic and strain energy values respectively, while is known as the work produced by external forces. Afterwards, based on Hamilton`s principle and neglecting the dynamic effect, the minimization of the Lagrangian functional leads to the Galerkin weak form of the equilibrium equation: = ∫ Λ − ∫ Λ − Λ Λ ∫ S − S ∫ C = 0 C (2) ∫ Ω = Ω ∫ Ω + ∫ Γ + Γ Ω (3) In the RPIM, the weak form has local support, which means that the discrete system of equations is developed firstly for every influence-domain. Consider e as the thickness of the specimen. In addition, b and t are presented the body and external traction force vectors respectively. Moreover, the external force vector applied on a close curve is identified as q vector. ∫ Ω = Ω ∫ { } Ω + ∫ { } Γ + { } Γ Ω (4) = − ( + + ) (5) In this study, all the integration cells are quadrilateral and contain approximately 9 nodes and × integration points inside, respecting the Gauss-Legendre quadrature scheme. Previous work, Vasheghani Farahani et al. (2015), found that this integration scheme maximizes its efficiency when = 3 . Basically, the theory of the continuum damage mechanics relies on the definition of the effective stress concept associated to the equivalent effective strain. It indicates the strain value related to the damage state, when the stress applied, is equivalent to the strain obtained from the undamaged state under the effective stress ̅ = : . Afterwards , the full effective stress tensor should be split into tensile and compressive components where ̅ = ̅ + + ̅ − [Cervera et al. (1996)]. Consequently, the equivalent effective tensile and compressive norms are adopted after splitting the stress, the reason is to obtain the octahedral normal and shear stress terms, ̅ − and ̅ − , as follows: ̅ + = √ ̅ + : − : ̅ + (6) ̅ − = √√3( ̅ − + ̅ − ) (7) where K is a material property depending on the ratio between the biaxial and uniaxial compressive strengths for concrete materials. This constant depends on the plasticity parameter assumed for concrete materials as = 1.16 . Hence, it is determined for this analysis as = 0.525 [Cervera et al. (1995)]. Moreover, Simo and Ju (1987) proposed the damage criterion for tensile and compressive states where the latter is known as Drucker-Prager cone for compression. Subsequently, + and − are identified as damage thresholds for tension and compression, respectively. The expansion of the damaged surface must be controlled by the mentioned parameters according to the following relations: + ( ̅ + , + ) = ̅ + − + ≤ 0 (8) − ( ̅ − , − ) = ̅ − − − ≤ 0 (9) It is remarkable that the uniaxial tensile and compressive strengths are considered as 0 + and 0 − respectively [Faria et al. (1998)]. 0+ = √ 0 + 1 0 + = 0+ √ (10)

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0− = √ √ 3 3 ( − √2) 0 −

(11) It is rational to emphasize that the damage grows if ̅ + = + ̅ − = − with regard to the initial conditions: 0+ = ̅ + 0− = ̅ − . Thus, damage is a function of damage thresholds in tensile and compressive states proving a rate-independent model [Cervera et al. (1996)]. + = max( 0+ , ( ̅ + )), + = + ( + ) (12) − = max( 0− , ( ̅ − )), − = − ( − ) (13) Considering all the aforementioned explanations and relationships, it is possible to establish the corresponding relations for local damage in both tension + and compression − states. + = + ( + ) = 1 − 0+ + exp( + (1 − + 0+ ⁄ )) if + ≥ 0+ (14) − = − ( − ) = 1 − 0− − (1 − − ) − − exp( − (1 − − 0− ⁄ )) if − ≥ 0− (15) So far, the standard local constitutive model has been formalized to obtain damage. The methodology adopted in this work to formulate the non-local damage is the following. Consider the local damage value for the corresponding integration points on the domain. Then, a circle with a certain radius, RGP , should be defined which covers the certain number of integration points (neighbor points). The circle is centred in the interest integration point which is being analysed for the non-local damage model. These neighbor points are the ones which should participate in damage localization process. The radius of this circle is calculated from = ℎ , it is dependent on the average distance between nodes, h . Consider the nodes discretised in specific divisions along x and y directions, h is computed based on the following relation: ℎ = /( ) = /( ) , being and D the dimensions of the specimen along x and y directions. Furthermore, is a variable controlling the corresponding radius varying between 0.5 and 2.1. It must be pointed that any integration point, for example the i th one, is identified by three components in a vector as = { } . The dimensions in x and y directions are defined as and respectively with regard to the weight of the corresponding integration point . Afterwards, the distance between the i th interest point and its j th neighbours must be calculated within the following relation: = √( − ) 2 + ( − ) 2 (16) This condition must be satisfied as a requirement of the proposed non-local damage mechanism: < . Subsequently, there exist applicable weight functions useful for the rest of analysis indicated on Table 1. Table 1: Weight function for localization process Order Weight Function 0

= 1 = − ( ) 2 2 + 1 = 2 ( ) 3 3 − 3 ( ) 2 2 + 1

2 nd

3 rd

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Then, the procedure continues with collecting the neighbour points taking part in damage localization. Due to this, the damage value of the interest point is shared on them according to their weights and it must be summed for all the points. Definitely this summation is obtained within an iterative process. The weight of integration points is accumulated for any acceptable neighbour point (satisfied < ) in tensile and compressive terms as: + / − = ∑ =1 (17) Additionally, when the damage sharing step happens, the weighted damage parameter, , on the neighbour points is adopted. Thus, the following relation governs the corresponding summation: +/− = ∑ ( + / − ) =1 (18) Finally, it is possible to obtain the non-local damage value for the i th interest point for both tensile and compressive states as follows: − + = + + and − − = − − (19) Considering all foregoing calculations, it is possible to accomplish the Cauchy stress tensor based on the following relation, Crisfield (1996): = (1 − − + ) ̅ + + (1 − − − ) ̅ − (20) being ̅ + and ̅ − the effective tensile and compressive stress tensors, respectively. Since the damage is scalar, it is required to use the equivalent von-Mises stress in the effective and Cauchy stress forms ( ̃ and ̃ , respectively) = 1 − ̃ ̃ (21) It is worth to mention that the obtained damage parameter, d , is the total damage driven from the non-local model. It is noticeable to mention that all of the afore-mentioned equations are rely on the Helmholtz free energy potential known as a function of the internal variables indicating the compressive and tensile behaviour of concrete materials as reported by Lubliner (1972); Faria et al. (1993); Salari et al. (2004) and Shao et al. (2006). It must be remarked that ≥ 0 since all the corresponding terms are non-negative as mentioned before. = (1 − + ) 0+ + (1 − − ) 0− (22) Afterwards, the computational implementation of the constitutive law is determined based on the strain field updated in each step of displacement enforcement. Due to this, the internal fields and damage variables are obtained. This algorithmic analysis is a strain-driven formalism extracted from the constitutive law. First, the standard local damage model, based on RPIM formulation, is employed to obtain the local damage and then it is developed to the non-local model to obtain the Cauchy stress tensor and most importantly the total non-local damage variable. The schematic representation of the algorithm is demonstrated in Fig. 1.