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

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)

Document Details

Document Type
Technical Report
Publication Date
Apr 01, 1969
Accession Number
AD0688786

Entities

People

  • Fred Schloss
  • Jerome S. Parsons
  • Wallace Yater

Tags

DTIC Thesaurus Topics

  • Accelerometers
  • Computer Programs
  • Computers
  • Impedance
  • Instrumentation
  • Materials
  • Measurement
  • Measuring Instruments
  • Mechanical Impedance
  • Modulus Of Elasticity
  • Shear Properties
  • Tensile Stress

Readers

  • Control Systems Engineering.
  • Mechanical Engineering/Mechanics of Materials.
  • Phased Array Antenna Design.