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Structure Resonance Analyzer

IP.com Disclosure Number: IPCOM000076336D
Original Publication Date: 1972-Feb-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 24K

Publishing Venue

IBM

Related People

Hopkins, WG: AUTHOR [+2]

Abstract

Conventional shaketables make use of a platform attached to a magnetically driven voice coil. The item to be vibrated is lashed to this platform. A second method involves deflecting the object by induction or eddy currents from an electromagnet located close to the object. This is successful up to 300 or 400 cycles per second.

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Structure Resonance Analyzer

Conventional shaketables make use of a platform attached to a magnetically driven voice coil. The item to be vibrated is lashed to this platform. A second method involves deflecting the object by induction or eddy currents from an electromagnet located close to the object. This is successful up to 300 or 400 cycles per second.

The method below offers a ten-fold increase in frequency range that an object may be subjected to, allowing more thorough resonance analysis. In the figure, two standard full range 5 inch speakers 1 connected in push-pull are mounted as shown into a test fixture 2. This allows an audio sine wave to be applied to the object 3 causing the object, such as a flat or circular sheet, to be deflected in phase with the applied signal. Nonlinearities of the speaker are unimportant. Only the results need be monitored by the use of a Bently Proximeter Detector or similar device. Object resonances can now be checked over a wide dynamic range rather quickly, over a range up to 3000 H(z).

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