Hydroelastic excitation of cylinders.

The transverse vibration of a bluff body in a steady fluid flow is a phenomenon that has been observed and discussed through the ages. Named after the Greek God of Wind Aeolius, the Aeolian Tones, such as are emitted by the wind in telephone or power lines, were known to the Greeks, who produced musical sounds from an Aeolian Harp by hanging it in a current of wind. The first recorded association of the transverse vibration with a periodic wake pattern was made by Leonardo Da Vinci, who observed and sketched the process of lternate periodic vortex shedding from a bluff body to form the staggered vortex trail in its wake. It is unlikely that prior to the nineteenth century many structural failures occurred due to hydrodynamic excitation. Wood, stone and brick were the main construction materials, and the elementary design methods used were very conservative ensuring that the structure had high frequency, large mass and a large damping factor. A very high flow velocity was therefore needed to initiate structural oscillations by vortex shedding and, if initiated these structural oscillations would usually be quickly damped out. During the nineteenth century the rapid advancement in the art of civil engineering design and the introduction and development of concrete and steel as a construction material led to the design of streamlined structures with more economical dimensions and consequently lower frequencies, smaller masses and smaller damping factors. Although design codes made a reasonable allowance for static loadings, dynanic loadings caused by earthquakes and hydrodynamic excitation were eirther ignored or underestimated.

Name thesis:degree_name

PhD

Level thesis:degree_level

Doctoral

Discipline thesis:degree_discipline

Engineering

Grantor dc:publisher

ResearchSpace@Auckland

Year dc:date.issued

1971

Author dc:creator

• Small, Arthur Francis, 1946-

Advisor dc:contributor.advisor

• Professor A. J. Raudkivi

Statement dc:rights

• Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

Licence dc:rights.uri

• https://researchspace.auckland.ac.nz/docs/uoa-docs/rights.htm

Language dc:language.iso

en

Handle dc:identifier.uri

https://hdl.handle.net/2292/2531

OAI identifier oai:identifier

oai:researchspace.auckland.ac.nz:2292/2531