PSI - Issue 13

ScienceDirect Available online at www.sciencedirect.com Available o line at ww.sciencedire t.com ienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structural Integrity 13 (2018) 1993–1998 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 Robust reference system for Digital Image Correlation camera recalibration in fieldwork Francisco Barros a , Pedro J. Sousa a , Paulo J. Tavares a, *, Pedro M. G. P. Moreira a a INEGI, Universidade do Porto, Rua Dr. Roberto Frias, 400, Porto 4200-465, Portugal Abstract Digital Image Correlation (DIC) is a modern powerful tool to acquire displacement fields in both laboratory and field work. Still, a number of severe limitations persist that can hinder the application of the method to objects in field work, where perfect stability of the cameras or the object itself cannot be enforced, or image acquisition is to be performed during long periods and the equipment has to be moved in the meantime. A common example of this problem is found in large structure monitoring, such as auto or railway bridges, landslides, peers or any other structure that requires displacement monitoring due to damage, often associated with fatigue and fracture in metallic structures. Accurate detection of camera movement across images of the same surface enable the computation of 3D point clouds with correct camera calibration values and geometrically aligned with other point clouds from previous time instants. An algorithm, which uses feature detection to recalibrate a stereo camera-pair after movement, was developed in this work. The cameras are originally calibrated i their initial position, and the world coordinates of detected features in the background are computed to serve as reference. In subsequent image capture following camera setup movement, the new camera positions are computed using the new coordinates of the featured reference points, as well as newly detected point correspondences between images from both cameras. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: Digital image correlation; Camera calibration; Auto-calibration; Structural monitoring © 2018 The Aut ors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. ECF22 - Loading and Environmental effects on Structural Integrity Robust reference system for Digital Image Correlation camera recalibration in fieldwork Francisco Barros a , Pedro J. Sousa a , Paulo J. Tavares a, *, Pedro M. G. P. Moreira a a INEGI, Universidade do Porto, Rua Dr. Roberto Frias, 400, Porto 4200-465, Portugal Abstract Digital Image Correlation (DIC) is a modern powerful tool to acquire displacement fields in both laboratory and field work. Still, a number of severe limitations persist that can hinder the application of the method to objects in field work, where perfect stability of the cameras or the object itself cannot be enforced, or image acquisition is to be perform d during long periods and the equipment has to be moved in the meantime. A common example of this problem is found in large structure monit ring, such as auto or railway bridges, la dslides, peers or any other structure that requires displacement monitoring d e to da age, often associated with f tigue and fracture in metallic tructures. Accurate d tection of camera movement acr ss images of the same surface enable the comput tion of 3D point clouds with correct cam ra calibrati n values and geometrically aligned with other point clouds from previous time instants. An algorithm, whi h uses feature detection to recalibrat a stereo camera-pair after movement, was devel ped in this work. The cameras are originally calibrated in their initial position, and the world coordinates of detected feature in the background are computed to serve as reference. In subsequent image capture following camera setup mov ment, the new camera positions are co ted using the new coordinates of the featured reference points, as well as newly detected point orr spondences between images from both cameras. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: Digital image correlation; Camera calibration; Auto-calibration; Structural monitoring

© 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.: +351-22-9578710. E-mail address: ptavares@inegi.up.pt * Corresponding author. Tel.: +351-22-9578710. E-mail ad ress: p avares@inegi.up.pt

* 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 o ganizers.

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.2018.12.218