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Development of a robust output-only strain based damage detection technique for wing-like structures, requiring a minimum number of sensors
Dissertation (MEng)--University of Pretoria, 2009.
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University of Pretoria
2013
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| _version_ | 1867613653678686208 |
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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 | © 2009 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, 2009. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/30065 |
| institution | University of Pretoria (South Africa) |
| last_indexed | 2026-06-10T12:39:34.197Z |
| 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:2263/30065 Development of a robust output-only strain based damage detection technique for wing-like structures, requiring a minimum number of sensors Heyns, P.S. (Philippus Stephanus) ulrich.spang@gmail.com Spangenberg, Ulrich Strain frf Ambient excitation Output-only response data Global damage detection Response-based approach UCTD Dissertation (MEng)--University of Pretoria, 2009. In recent years more emphasis has been placed on in-situ condition based monitoring of engineering systems and structures. Aerospace components are manufactured from composite materials more often. Structural health monitoring (SHM) systems are required in the aerospace industry to monitor the safety and integrity of the structure and will ensure that composites reach its full potential within the industry. Damage detection techniques form an integral part of such SHM systems. With this work a damage detection technique is developed for intended eventual use on composite structures, but starting first on isotropic structures. The damage mechanism that is of interest is delamination damage in composites. A simple numerical equivalent is implemented here however. Two damage indicators, the strain cumulative damage factor (SCDF) and the strain-frequency damage level (SFDL) are introduced. The respective damage indicators are calculated from output-only strain and acceleration response data. The effectiveness of the system to detect damage in the structure is critically evaluated and compared to other damage detection techniques such as the natural frequency method. The sensitivity to damage and performance of both these indicators is examined numerically by evaluating two deterministic damage cases. The numerical study is enhanced through the use of an updated finite element model. The minimum number of sensors capable of detecting the presence and locate damage spatially is determined from numerical simulations. Monte Carlo type analysis is performed by letting the damaged area vary stochastically and calculating the respective damage indicators. The model updating procedure from measured mobility frequency response functions (FRFs) is described. The application of the technique to real structures is examined experimentally. Two test structures with two different damage scenarios are examined. The spatial location and presence of damage can be established from both the SCDF and SFDL values, respectively. The spatial location obtained from the SCDF values corresponded to the known damage location for both the numerical and experimental study. The SFDL proved to be more sensitive than the natural frequency method and could be used to calculate the level of damage within the structure. Mechanical and Aeronautical Engineering unrestricted 2013-09-07T17:52:17Z 2011-05-10 2013-09-07T17:52:17Z 2011-04-12 2009 2010-12-03 Dissertation Spangenberg, U 2009, Development of a robust output-only strain based damage detection technique for wing-like structures, requiring a minimum number of sensors, MEng dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://hdl.handle.net/2263/30065 > C11/21/ag http://hdl.handle.net/2263/30065 http://upetd.up.ac.za/thesis/available/etd-12032010-000847/ © 2009 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 | Strain frf Ambient excitation Output-only response data Global damage detection Response-based approach UCTD Development of a robust output-only strain based damage detection technique for wing-like structures, requiring a minimum number of sensors |
| title | Development of a robust output-only strain based damage detection technique for wing-like structures, requiring a minimum number of sensors |
| title_full | Development of a robust output-only strain based damage detection technique for wing-like structures, requiring a minimum number of sensors |
| title_fullStr | Development of a robust output-only strain based damage detection technique for wing-like structures, requiring a minimum number of sensors |
| title_full_unstemmed | Development of a robust output-only strain based damage detection technique for wing-like structures, requiring a minimum number of sensors |
| title_short | Development of a robust output-only strain based damage detection technique for wing-like structures, requiring a minimum number of sensors |
| title_sort | development of a robust output only strain based damage detection technique for wing like structures requiring a minimum number of sensors |
| topic | Strain frf Ambient excitation Output-only response data Global damage detection Response-based approach UCTD |
| url | http://hdl.handle.net/2263/30065 http://upetd.up.ac.za/thesis/available/etd-12032010-000847/ |