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 Procedia Structu al Integrity 5 (2017) 875–882 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 Approximation of the crack driving force for cracks at notches under static and cyclic loading M.Madia a *, D. Tchoffo Ngoula b , U. Zerbst a , H. Th. Beier b a Bundesanstalt für Materialforschung und -prüfung (BAM), Division 9.1, Unter den Eichen 87, D-12205 Berlin, Germany b Technische Universität Darmstadt, Materials Mechanics Group, Franziska-Braun-Str. 3, D-64287 Darmstadt, Germany Abstract The work deals with the efficient calculation of the elastic-plastic crack driving force ( -integral for monotonic loading and ∆ -integral under cyclic loading) for short cracks at notches as essential parameter for the reliable static and fatigue assessment of notched structures. The - or ∆ -integral is calculated based on analytical solutions for stress intensity factors, estimated by means of well-known weight function solutions in the case of cracks under power-law stress distributions. A plasticity-correction function is applied to the stress intensity factors to obtain the final expression of the crack driving force. The comparison between analytical solutions and finite element calculations in case of cracks at the weld toe in welded joints shows good agreement. © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017. Keywords: Structural integrity; fracture mechanics; crack driving force; notches 1. Introduction The most widely spread standards and guidelines for the structural assessment of structures containing cracks, such as EPRI, R6, BS7910 or SINTAP/FITNET, rely on the so-called EPRI estimation scheme (Kumar et al., 1981) or on the reference str ss method introduced by Ainsworth (1984) for the evaluation of the crack driving force, see 2nd International Conference on Structural Integrity, ICSI 2017, 4-7 September 2017, Funchal, Madeira, Portugal Approximation of the crack driving force for cracks at notches under static and cyclic loading M.Madia a *, D. Tchoffo Ngoula b , U. Zerbst a , H. Th. Beier b a Bundesanstalt für Materialfor chung und -prüfung (BAM), Division 9.1, Unter den Eichen 87, D-12205 Berlin, b Technische Universität Darmstadt, Materials Mechanics Group, Franziska-Braun-Str. 3, D-64287 Darmstadt, Germany Abstract The work deals with the efficient calculation of the elastic-pla tic crack driving forc ( -int gral for monotonic loading and ∆ -int gral under cyclic loading) for short ra ks at notches as essen al parameter the rel able static and fatigue assessment of notched structures. The - or ∆ -integral s calculated based on analytical solutions for ess intensity f ctors, estimated by means of well-known weight function solutions in the cas of cracks under p wer-law stress distributions. A plasticity-correction function is applied to the s ress int sity factors to obt in the final expression of the crack driving force. The comparison between analytical solutio s and finite element calculations in case of cracks at the weld toe in w lded joints shows good greement. © 2017 The Authors. Publ shed by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ICSI 2017. Keywords: Structural integrity; fracture mechanics; crack driving force; notches 1. Introduction The most widely spread standards and guidelines for the structural assess ent of structures containing cracks, such as EPRI, R6, BS7910 r SINTAP/FITNET, rely on the so-called EPRI estimation scheme (Kumar et al., 1981) or on the reference stress method introduced by Ainsworth (1984) for the evaluation of the crack driving force, see © 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.

* Corresponding author. Tel.: +49 30 8104-4166. E-mail address: mauro.madia@bam.de * Correspon ing autho . Tel.: +49 30 8104-4166. E-mail address: mauro.madia@bam.de

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.2017.07.111 * 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.