Accession Number : AD0659473

Title :   EXPERIMENTAL TECHNIQUE FOR DETERMINING FIXED-BASE NATURAL FREQUENCIES OF STRUCTURES ON SINGLE NONRIGID ATTACHMENT POINTS.

Descriptive Note : Memorandum rept.,

Corporate Author : NAVAL RESEARCH LAB WASHINGTON D C

Personal Author(s) : Remmers,G. M. ; Mayo,H. C.

Report Date : 31 AUG 1967

Pagination or Media Count : 24

Abstract : Experimental verification of a technique for determining fixed-base natural frequencies of structures mounted on a single non-rigid support is provided. The feasibility of this technique of frequency determination was explored by measurements on individual double cantilever beams while each was attached to a frame designed to simulate characteristics of shipboard mounting conditions. The beams fundamental frequencies were distributed throughout the frequency range normally considered in shock design and thus each beam simulated a different lightweight equipment-foundation system. Response was measured at the required locations with high sensitivity (acceleration) transducers and circuitry. Instrumentation normally employed for mechanical mobility measurements proved suitable in these vibration tests after modification to improve frequency stability and resolution. The scope of this experimental work is limited to the one-foundation problem. The two-foundation problem is expected to be the subject of future experimentation. (Author)

Descriptors :   (*STRUCTURES, RESONANT FREQUENCY), (*RESONANT FREQUENCY, TEST METHODS), SHIPBOARD, VIBRATION, SHOCK(MECHANICS), FOUNDATIONS(STRUCTURES), EXPERIMENTAL DATA

Subject Categories : Marine Engineering
      Structural Engineering and Building Technology
      Test Facilities, Equipment and Methods

Distribution Statement : APPROVED FOR PUBLIC RELEASE