PSI - Issue 13

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 Structural Integrity 13 (2018) 2053–2 58 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. ECF22 - Loading and Environmental effects on Structural Integrity On the effect of weld defects on the fatigue strength of beam welded butt joints Ann-Christin Hesse a , Thomas Nitschke-Pagel a , Klaus Dilger a a Institute of Joining and Welding, TU Braunschweig, Langer Kamp 8, 38106 Braunschweig, Germany Abstract Modern guidelines concerning the fatigue strength of welded components are often based on the nominal stress concept. These guidelines are valid for fusion welded steels but do not distinguish between different welding processes. However, different welding processes can l ad o significant differe ces in the resulting weld geometry. Thi is particular true for ar welded components in comparison to beam welded components. Furthermore, it is well known, that the geometry of welded joints effects the fatigue strength severely. Therefore, it can be expected that beam welds behave differently to arc welds in fatigue tests. In this study, electron beam and laser beam welded samples of different thicknesses made from fine-grained steels were tested in fatigue tests under a constant amplitude loading. In order to assess the effects of weld defects on the fatigue strength, samples with defined weld defects (e.g. axial misalignment) were included in the study as well. The weld geometry of each sample was measured a d evaluated according to the quality groups i ISO 13919-1. Additional numerical notch stre s calculati ns were performed. Finally, a correlation between the quality groups according to ISO 13919-1 and the nominal cyclic stress at 2*106 load cycles with a survival probability of 97,5% was proposed. This correlation allows users of beam welding processes to predict the fatigue strength of components under the condition that certain quality levels according to ISO 13919-1 are met. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: beam welds; fatigue strength; high cycle fatigue; weld imperfections; butt welds; steels Nomenclature FAT fatigue stress range at N = 2∙10 6 load cycles, at a survival probability of 97.7% and a slope of m = 3 M Mean stress sensitivity factor m Inverse slope of S-N curve N number of load cycles t Plate thickness in mm POS Probability of survival Δσ Stress range in MPa R Stress ratio QL Quality level © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. ECF22 - Loading and Environmental effects on Structural Integrity On the effect of weld defects on the fatigue strength of beam welded butt joints Ann-Christin Hesse a , Thomas Nitschke-Pagel a , Klaus Dilger a a Institute of Joining and Welding, TU Braunschweig, Langer Kamp 8, 38106 Braunschweig, Germany Abstract Modern guidelines concerning the fatigue strength of welded components are often based on the nominal stress concept. These guidelines are valid for fusion welded steels but do not distinguish between different welding processes. However, different welding processes can lead to significant differences in the resulting weld geometry. This is particular true for arc welded components in comparison to beam welded components. Furthermore, it is well known, that the geometry of welded joints effects the fatigue strength severely. Therefore, it can be expected that beam welds behave differently to arc welds in fatigue tests. In this study, electron beam and laser beam welded samples of different thicknesses made from fine-grained steels were tested in fatigue tests under a constant amplitude loading. In order to assess the effects of weld defects on the fatigue strength, samples with defined weld defects (e.g. axial isalignment) were included in the study as well. The weld geometry of each sample was measured and evaluated according to the qu lity groups in ISO 13919-1. Additi al numerical notch stress c lculations ere performed. Finally, a correlation between the quality groups according to ISO 13919-1 and the nominal cyclic stress at 2*106 load cycles with a survival probability of 97,5% was proposed. This correlation allows users of beam welding processes to predict the fatigue strength of components under the condition that certain quality levels according to ISO 13919-1 are met. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: beam welds; fatigue strength; high cycle fatigue; weld imperfections; butt welds; steels Nomenclature FAT fatigue stress range at N = 2∙10 6 load cycl s, at a survival probabi i y of 97.7% and a slope of m = 3 M Mean stress sensitivity factor m Inverse slope of S-N curve N number of load cycles t Plate thickness in mm POS Probability of survival Δσ Stress range in MPa R Stress ratio QL Quality level © 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 © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. 2452-3216 © 2018 The Authors. Published by Elsevier B.V. Peer review under r sponsibility of the ECF22 organizers.

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 ECF22 organizers. 10.1016/j.prostr.2018.12.209