FORCE FREQUENCY SHIFTING FOR STRUCTURAL EXCITATION

✍ Scribed by L.L. Koss

• Book ID: 102612907
• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 215 KB
• Volume: 219
• Category: Article
• ISSN: 0022-460X
• DOI: 10.1006/jsvi.1998.1881

✦ Synopsis

This paper develops concepts and equations for the characterisation of a frequency shifting force shaker which can be employed to excite low frequency structures into resonance. Force which is developed at a high frequency can be employed for excitation at a very low frequency. Frequency shifting is accomplished by moving a shaker to and fro in a reciprocating manner parallel to the structure which it is exciting while the shaker force acts perpendicular to the structure. Simple equations which relate the generalised force ratio to a length ratio are developed along with the positions on a structure where a frequency shifting shaker should be placed. This information allows the engineer some simple choices for the design and operation of a frequency shifting shaker. Also, this investigation develops criteria for which the frequency shifting shaker outperforms an ordinary shaker operating at the natural frequency of a structure.