Accession Number : AD0639912

Title :   DETERMINATION OF FIXED BASE NATURAL FREQUENCIES OF DUAL FOUNDATION SHIPBOARD EQUIPMENTS BY SHAKE TESTS,

Corporate Author : NAVAL RESEARCH LAB WASHINGTON D C

Personal Author(s) : PETAK,L. P. ; O'Hara,G. J.

Report Date : 23 AUG 1966

Pagination or Media Count : 17

Abstract : The report investigates the application of resonance testing to determine the fixed base natural frequencies of an in-place shipboard equipment-foundation system which is supported at two base points. Translation of the base points can cause the structure to rotate as it translates. A method was previously proposed which required the simultaneous use of two shakers capable of phase control and a range of force ratios at each driving frequency; this method would be quite difficult and expensive to apply in the field. A new technique is proposed herein which requires only one shaker to be applied at a time, thereby reducing the difficulties and restrictions considerably. An application of the technique to a theoretical system, and an analog simulation of a shake test utilizing the new method are presented. (Author)

Descriptors :   (*VIBRATION, TEST METHODS), SHIPBOARD, FOUNDATIONS(STRUCTURES), RESONANCE

Subject Categories : Marine Engineering
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE