Accession Number : AD0006354


Title :   DYNAMIC TESTING OF MATERIALS AND STRUCTURES WITH A NEW RESONANCE-VIBRATION EXCITER AND CONTROLLER


Corporate Author : MINNESOTA UNIV MINNEAPOLIS


Personal Author(s) : Lazan, B ; Gannett, A ; Kirmser, P ; Klumpp, J ; Brown, J


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/006354.pdf


Report Date : Dec 1952


Pagination or Media Count : 49


Abstract : The nature of near-resonance vibration and response characteristics are discussed to clarify the relationships among resonance amplification factor, damping energy and dynamic modulus of elasticity. A newly developed machine is described for exciting and controlling resonance or near resonance vibrations in materials and joints under various types of stress. This machine imposes an adjustable while running mechanical exciting force at a controllable frequency and by means of automatic electronic controls maintains (a) the desired vibration phase angle (usually 900 for resonance) by controlling the frequency of the exciting force, and (b) the desired magnitude of the excited force by automatically controlling the magnitude of the exciting force. Equations are developed for determining the resonance amplification and other properties from the machine readings. The stability and accuracy of the machine are discussed. Data are presented on the damping and elasticity properties of aluminum and mild steel, and these are compared with results procured in rotating cantilever beam equipment. The resonance response, damping, and elasticity properties of a bolted joint were determined and the effects of bolt tension and molybdenum disulfide lubrication are illustrated and partially analysed.


Descriptors :   *VIBRATION , *RESONANCE , MODULUS OF ELASTICITY , TEST EQUIPMENT , TENSION , SOLID LUBRICANTS , DYNAMIC TESTS , CANTILEVER BEAMS , BOLTED JOINTS


Subject Categories : Mechanics


Distribution Statement : APPROVED FOR PUBLIC RELEASE