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Validation of a New Approach to Condition Monitoring of Offshore Structures – Aspects of a Scale Model
Author(s) -
Thompson M.,
Harper M.
Publication year - 2004
Publication title -
strain
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.477
H-Index - 47
eISSN - 1475-1305
pISSN - 0039-2103
DOI - 10.1046/j.1475-1305.2003.00105.x
Subject(s) - reflection (computer programming) , acoustics , point (geometry) , submarine pipeline , scale (ratio) , signal (programming language) , structural health monitoring , transmission (telecommunications) , computer science , scale model , mode (computer interface) , range (aeronautics) , geology , marine engineering , engineering , structural engineering , physics , telecommunications , geotechnical engineering , geometry , mathematics , aerospace engineering , quantum mechanics , operating system , programming language
Offshore structures have a finite design life and many are approaching that limit. The expected life cannot be extended without some justification, such as the inclusion of a structural monitoring system. This project is aimed at using long‐range propagation of acoustic signals through a structure to detect changes induced by damage, cracking or flooding of hollow members. It is based on the idea that, if a change occurs within the structure, this will induce changes in acoustic signals transmitted between two points on it. These changes will only occur after a certain time in the history of the signal, and this time corresponds to the minimum travel time from the transmission point to the reception point via the point of damage. A scale model in polycarbonate has been used to demonstrate that using acoustic waves to interrogate a multi‐connected structure can successfully locate damage. This has been done with sensors all at the top ( reflection mode ) and with transmitters at the top and receivers at the bottom ( tomographic mode ). The method is effective when we use very small numbers of source and sensor positions in proportion to the number of structural members being monitored for damage. The reflection geometry is much more practical from the point of view of application to offshore structures because all transducers and wiring can be located above the splash zone.