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Online damage detection on shafts using torsional and undersampling measurement techniques
Dissertation (MEng)--University of Pretoria, 2013.
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University of Pretoria
2013
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| _version_ | 1867613588740374528 |
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| access_status_str | Open Access |
| author2 | Heyns, P.S. (Philippus Stephanus) |
| author_browse | Heyns, P.S. (Philippus Stephanus) |
| author_facet | Heyns, P.S. (Philippus Stephanus) |
| collection | Thesis |
| dc_rights_str_mv | © 2013 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria |
| description | Dissertation (MEng)--University of Pretoria, 2013. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/25437 |
| institution | University of Pretoria (South Africa) |
| last_indexed | 2026-06-10T12:38:32.434Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2013 |
| publishDateRange | 2013 |
| publishDateSort | 2013 |
| publisher | University of Pretoria |
| publisherStr | University of Pretoria |
| record_format | dspace |
| source_str | UPSpace — University of Pretoria Institutional Repository |
| spelling | oai:repository.up.ac.za:2263/25437 Online damage detection on shafts using torsional and undersampling measurement techniques Heyns, P.S. (Philippus Stephanus) vbhana7@gmail.com Bhana, Vishal Bhooshan Shaft Catastrophic failure Cracks in rotors Defects of rotating machinery UCTD Dissertation (MEng)--University of Pretoria, 2013. The presence of cracks in rotors is one of the most dangerous defects of rotating machinery. This can lead to catastrophic failure of the shaft and long out-of-service periods. The occurrence of a crack in a rotating shaft introduces changes in flexibilities which alters the dynamics during operation. This research deals with detecting damage in rotors by means of constantly monitoring the variation in the rotor’s dynamics during normal operating conditions. This project entails a computer finite element section as well as an experimental investigation. The flexibility in the region of the crack is different from an uncracked section. A finite element model of a shaft is built and investigated. The damaged model is the same except that the nodes in the location of the crack are not equivalenced in order to represent the crack. A simple constant cross-sectional shaft with semi-circular transverse surface cracks varying in size have been modelled on the Patran finite element software and a normal modes analysis was done using the Nastran solver. The results revealed a change in the natural frequencies due to the variation in the size of the crack. The experimental investigation involved creating sample shafts with damage positioned in them that would closely resemble what one may find in actual real-life situations and the dynamics during rotation with various torsional loadings are investigated and monitored using three methods. A fibre-optical sensor, Digital image correlation system and telemetry strain gauges were used. Undersampling techniques were used for the DIC system. Results showed that the fibre-optic sensor is by far the most favourable as it is able to detect damage under constant operation. The finite element model was updated by re-modelling the geometry, damage and material properties. The solution of the analysis matched the experimental results closely and model verification was achieved. Mechanical and Aeronautical Engineering unrestricted 2013-09-06T21:19:50Z 2013-06-12 2013-09-06T21:19:50Z 2013-04-15 2013-06-12 2013-06-10 Dissertation Bhana, V 2013, Online damage detection on shafts using torsional and undersampling measurement techniques, MEng dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://hdl.handle.net/2263/25437 > E13/4/727/gm http://hdl.handle.net/2263/25437 http://upetd.up.ac.za/thesis/available/etd-06102013-173135/ © 2013 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria application/pdf University of Pretoria |
| spellingShingle | Shaft Catastrophic failure Cracks in rotors Defects of rotating machinery UCTD Online damage detection on shafts using torsional and undersampling measurement techniques |
| title | Online damage detection on shafts using torsional and undersampling measurement techniques |
| title_full | Online damage detection on shafts using torsional and undersampling measurement techniques |
| title_fullStr | Online damage detection on shafts using torsional and undersampling measurement techniques |
| title_full_unstemmed | Online damage detection on shafts using torsional and undersampling measurement techniques |
| title_short | Online damage detection on shafts using torsional and undersampling measurement techniques |
| title_sort | online damage detection on shafts using torsional and undersampling measurement techniques |
| topic | Shaft Catastrophic failure Cracks in rotors Defects of rotating machinery UCTD |
| url | http://hdl.handle.net/2263/25437 http://upetd.up.ac.za/thesis/available/etd-06102013-173135/ |