PSI - Issue 5

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com cienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 P o edi Structural Integr ty 5 (2017) 85–92 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. 2nd International Conference on Structural Integrity, ICSI 2017, 4-7 September 2017, Funchal, Madeira, Portugal Plasticity induced closure under variable amplitude loading in AlMgSi aluminum alloys L.F.P. Borrego a,b *, J.D. Costa a , JA.M. Ferreira a a CEMMPRE, University of Coimbra, Department of Mechanical Engineering, Rua Luís Reis Santos, 3030-788, Coimbra, Portugal b Instituto Politécnico de Coimbra, ISEC, Department of Mechanical Engineering,Rua Pedro Nunes, 3030-199 Coimbra, Portugal Abstract Fatigue crack propagation tests under peak overloads, as well as High-Low and Low-High block loading sequences have been performed in aluminum alloy specimens. The bserved transient crack cl sure level is discussed in terms of loading sequence, load change magnitude and  K baseline levels. The crack closure level is compared with the crack growth transients. A good agreement between experimental and predicted crack growth rates is obtained when the partial crack closure effect is properly taken into account. Therefore, plasticity-induced crack closure plays an important role on the load interaction effects observed in aluminum alloys. © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017. Keywords: Damage Tolerance Overloads, block loading, partial crack closure, plasticity-induced crack closure 1. In roduction Service conditions generally involve random or variable amplitude, rather than constant amplitude loads. Significant accelerations and/or retardations in crack growth rate can occur as a result of these load variations. Thus, an accurate prediction of fatigue life requires an adequate evaluation of these load interaction effects. To attain this objective several type of simple variable amplitude load sequences must be analyzed. Several mechanisms have been proposed to explain the crack growth transients following variable a plitude loading sequences, which includes 2nd International Conference on Structural Integrity, ICSI 2017, 4-7 September 2017, Funchal, Madeira, Portugal Plasticity induced closure under variable amplitude loading in AlMgSi aluminum alloys L.F.P. Borrego a,b *, J.D. Costa a , JA.M. Ferreira a a CEMMPRE, University of Coimbra, Department of Mechanic l Engineering, Rua Luís Reis Santo 788, Coi bra, Portugal b Instituto Politécnico de Coimbra, ISEC, Department of Mechanical Engineering,Rua Pedro Nunes, 3030-199 Coimbra, Portugal Abstract Fatigue crack propagation tests under peak ov rloads, as well as High-Low and Low-High block loading sequence have been p rform d in alumi um alloy specimens. The observed transient crack closure level is discuss in terms of loading seque c , load change magnitude and  K baseline levels. The rack closure level is compared with the crack growth transients. A good agreement betwee experimental and p dicted rack growth rates is btained whe the partial crack closure effect is properly taken into acco nt. Theref re, plasticity-induced crack closure plays an important role on the load interaction effects observed in aluminum alloys. © 2017 The Authors. Publ shed by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017. Keywords: Damage Tolerance Overloads, block loading, partial crack closure, plasticity-induced crack closure 1. Introduction Service conditions generally involve random or variable amplitude, rath r than constant amplitude load . Significant accelerations and/or retardations in crack growth rate ca occur as a result of these load variations. Thus, an a curat prediction of fatigue life requires an adequat evaluation of these load interaction ffects. To attain this objective sev ral type of simple variable amplitude load sequences must be analyzed. Several me hanisms ave be n proposed to explain the crack growth transients following variable amplitude loading sequences, which includes © 2017 The Authors. Published by Elsevier B.V. Peer-review under r sponsibility 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.

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.2017.07.072 * 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. * Correspon ing author. Tel.: +351 962560101; fax: +351 239790331. E-mail address: borrego@isec.pt * Corresponding author. Tel.: +351 962560101; fax: +351 239790331. E-mail address: borrego@isec.pt