Dynamics of a spherical vibration absorber


Abstract eng:
Wind excited vibrations of slender structures such as towers, masts or certain types of bridges can be reduced using passive or active vibration absorbers. If there is available only a limited vertical space to install such a device, a spherical type of absorber can be recommended. In general, it is a semi-spherical horizontal dish in which a sphere of a smaller diameter is rolling. Ratio of both diameters, mass of the rolling sphere, quality of contact surfaces and other parameters should correspond with characteristics of the structure. The spherical absorber is modelled as a holonomous system. Using Lagrange equations of the second type, governing non-linear differential system is derived. The function and effectiveness of the absorber identical with those installed at the existing TV towers was examined in the laboratory of the Institute of Theoretical and Applied Mechanics. The response spectrum demonstrates a strongly non-linear character of the absorber. The response amplitudes at the top of a TV tower with spherical absorber were reduced to ¤ of their original values.

Contributors:
Publisher:
Institute of Theoretical and Applied Mechanics AS CR, Prague
Conference Title:
Conference Title:
Engineering Mechanics 2003
Conference Venue:
Svratka (CZ)
Conference Dates:
2003-05-12 / 2003-05-15
Rights:
Text je chráněný podle autorského zákona č. 121/2000 Sb.



Record appears in:



 Record created 2014-10-24, last modified 2014-11-18


Original version of the author's contribution as presented on CD, DYN. :
Download fulltext
PDF

Rate this document:

Rate this document:
1
2
3
 
(Not yet reviewed)