Accession Number : AD0688786

Title :   THE MEASUREMENT OF DYNAMIC PROPERTIES OF MATERIALS USING A TRANSFER impedance technique,

Corporate Author : NAVAL SHIP RESEARCH AND DEVELOPMENT CENTER WASHINGTON D C

Personal Author(s) : Parsons,Jerome S. ; Yater,Wallace ; Schloss,Fred

Report Date : APR 1969

Pagination or Media Count : 39

Abstract : The application of mechanical impedance techniques to the measurement of dynamic properties of materials is presented. The method is flexible in that it can be employed over a wide frequency range for a variety of materials (20 to 10,000 Hz for rubberlike compounds). The method was used to determine the complex Young's modulus, propagation constants, characteristic impedance, loss factor, etc., of viscoelastic materials. The specimen is suspended vertically and blocked at the upper end by means of a stiff force gage attached to a large isolated mass. A static tensile stress, which can be varied, ensures proper vertical alignment for the axial excitation applied at the free end of the sample. The motion of the free end is measured with an accelerometer. Instrumentation was developed to measure the phase angle between the two transducer signals to within 0.2 deg from 10 to 20,000 Hz. A computer program was written to expedite the analysis of the data. The method and computer program can also be applied to the measurement of dynamic shear properties of rubberlike materials. (Author)

Descriptors :   (*VISCOELASTICITY, TEST METHODS), MODULUS OF ELASTICITY, VISCOELASTICITY, FORCE(MECHANICS), TENSILE PROPERTIES, STRESSES, SHEAR STRESSES, ELASTOMERS, ACCELEROMETERS, INSTRUMENTATION, TRANSDUCERS, COMPUTER PROGRAMS, MATHEMATICAL MODELS, CALIBRATION, POISSONS RATIO, TEST EQUIPMENT

Subject Categories : Test Facilities, Equipment and Methods
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE