Accession Number:

ADD015853

Title:

Method and Device for Measuring Underwater Vehicle Hull Vibration.

Descriptive Note:

Patent, filed 25 Jul 91, patented 4 May 93,

Corporate Author:

DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s):

Report Date:

1993-05-04

Pagination or Media Count:

5.0

Abstract:

A method and device for measuring higher mode vibrational energy is provided. The device includes a plurality of sensors placed with uniform spacing around the circumference of a structure and a processing unit. The sensor placement may be either on the inside or the outside of a structure depending on the structure and on the experiment. In operation, signals from individual sensors, preamplified if required, are fed to processing equipment. The processing equipment performs a double Fast Fourier Transform. The first transform is done on temporal data thereby providing an output representing a frequency spectrum. The second transform is performed on simultaneous data readings from all sensor locations thereby providing an output representing a spectrum of mode numbers. The combining of these outputs provides a three-dimensional plot of amplitude versus frequency and mode number.

Subject Categories:

  • Marine Engineering
  • Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE