PSI - Issue 11

First page Table of contents Previous page 272 Next page Last page

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com ScienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structu al Integrity 11 (2018) 21 –217 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000 – 000 ScienceDirect Structural Integrity Procedia 00 (2018) 000 – 000

www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia

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. XIV International Conference on Building Pathology and Constructions Repair – CINPAR 2018 Model parameter estimation using Bayesian and deterministic approaches: the case study of the Maddalena Bridge A. De Falco a , M. Girardi b , D. Pellegrini b , L. Robol b , G. Sevieri c * a Department of Energy, Systems, Territory and Constructions Engineering, DESTEC, University of Pisa, Italy b Institute of Information Science and Technologies "A. Faedo", ISTI-CNR, Via Moruzzi, 1, Pisa, Italy c Department of Civil and Industrial Engineering, DICI, University of Pisa, Italy Finite element modeling has become common practice for assessing the structural health of historic constructions. However, because of the uncertainties typically affecting our knowledge of the geometrical dimensions, material properties and boundary conditions, numerical models can fail to predict the static and dynamic behavior of such structures. In order to achieve more reliable predictions, important information can be obtained measuring the structural response under ambient vibrations. This wholly non-destructive technique allows obtaining very accurate information on the structure’s dynamic properties (Brincker and Ventura (2015)). Moreover, when experimental data is coupled with a finite element model, an estimate of the boundary conditions and the mechanical properties of the constituent materials can also be obtained via model updating procedures. This work presents two different model updating procedures. The first relies on construction of local parametric reduced-order mod ls embedded in a trust region scheme to minimize the distance between the natural frequencies experimentally determined and the corresponding numerically valuated on s (Girardi et al. (2018)). The second has b en developed within a Bayesian statistical framework and uses both frequencies and mode shapes (Yuen (2015)). Both algorithms are used in conjunction with the NOSA-I ACA code for calculation of the eigenfr quencies and eigenvectors. These procedures are llustrated in the case study of the medieval Maddalena Bridg in Borgo a Mozzano (It ly). Experimental data, frequencies an mode shapes, acquired in 2015 (Azzara et al. (2017)) have enabled calibration of the ridge’s constit uent materials and boundary conditions. XIV International Conference on Building Pathology and Constructions Repair – CINPAR 2018 Model parameter estimation using Bayesian and deterministic approaches: the case study of the Maddalena Bridge A. De Falco a , M. Girardi b , D. Pellegrini b , L. Robol b , G. Sevieri c * a Department of Energy, Systems, Territory and Constructions Engineering, DESTEC, University of Pisa, Italy b Institute of Information Science and Technologies "A. Faedo", ISTI-CNR, Via Moruzzi, 1, Pisa, Italy c Department of Civil and Industrial Engineering, DICI, University of Pisa, Italy Abstract Finite element modeling has become common practice for assessing the structural health of historic constructions. However, because of the uncertainties typically affecting our knowledg f the geometrical dimensions, material properties and boundary conditions, numerical models can fail to predict the static and dynamic behavior of such structures. In order to achieve more reliable predictions, important information can be obtained measuring the structural response under ambient vibrations. This wholly non-destructive technique allows obtaining very accurate information on the structure’s dynamic properties (Brincker and Ventura (2015)). Moreover, when experimental data is coupled with a finite element model, an estimate of the boundary conditions and the mechanical properties of the constituent materials can also be obtained via model updating procedures. This work presents two different model updating procedures. The first relies on construction of local parametric reduced-order models embedded in a trust region scheme to minimize the distance between the natural frequencies experimentally determined and the corresponding numerically evaluated ones (Girardi et al. (2018)). The second has been developed within a Bayesian statistical framework and uses both frequencies and mode shapes (Yuen (2015)). Both algorithms are used in conjunction with the NOSA-ITACA code for calculation of the eigenfrequencies and eigenvectors. These procedures are illustrated in the case study of the medieval Maddalena Bridge in Borgo a Mozzano (Italy). Experimental data, frequencies and mode shapes, acquired in 2015 (Azzara et al. (2017)) have enabled calibration of the bridge’s constit uent materials and boundary conditions. Abstract

© 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Copyright © 2018 Elsevier B.V. All rights reserved. Peer-review under responsibility of the CINPAR 2018 organizers Copyright © 2018 Elsevier B.V. All rights reserved. Peer-review under responsibility of the CINPAR 2018 organizers Copyright © 2018 Elsevier B.V. All rights reserved. Peer-review under responsibility of the CINPAR 2018 organizers

Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation. Keywords: Model updating; FEM; Trust region method; Proxy models; Frequency optimization; Bayesian updating; Masonry bridges. Keywords: Model updating; FEM; Trust region method; Proxy models; Frequency optimization; Bayesian updating; Masonry bridges.

* Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452-3216 Copyright © 2018 Elsevier B.V. All rights reserved. Peer-revi w u er responsibility of the CINPAR 2018 organizers. 2452-3216 Copyright © 2018 Elsevier B.V. All rights reserved. Peer-review under responsibility of the CINPAR 2018 organizers. * Corresponding author. Tel.: +39-349-213-8290. E-mail address: giacomo.sevieri@unifi.it * Corresponding author. Tel.: +39-349-213-8290. E-mail address: giacomo.sevieri@unifi.it

Made with FlippingBook Annual report maker