DILATATION CONSTANTS AND COMPLEX RATIO FROM FORCED VIBRATION OF A FREE VISCOELASTIC SPHERE,

Abstract

The technique of forced vibration has been applied to the study of the properties of viscoelastic materials. It is found, through the analysis of a free sphere with a harmonic oscillating internal source, that the vibration amplitude ratio of two measuring points is associated with the complex dilatational constants and the complex ratio of the material, a quantity directly related to the complex Poisson's ratio. Therefore, from the criterion of maximum amplitude ratio (i.e. by adjusting the frequency of the source until the amplitude ratio reaches maximum), these properties can be expressed in terms of the amplitude ratios and their frequencies. For the convenience of laboratory testing, two particular amplitude ratios, in conjunction with their frequencies, have been employed for this purpose. Simple expressions are given, relating the properties of the test material to quantities measurable in the laboratory, namely the maximum amplitude ratios and their corresponding frequencies. (Author)

Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1965
Accession Number
AD0611751

Entities

People

  • T. M. Lee

Organizations

  • Cold Regions Research and Engineering Laboratory

Tags

DTIC Thesaurus Topics

  • Amplitude
  • Buildings And Structures
  • Doppler Effect
  • Frequency
  • Frequency Shift
  • Materials
  • Research Facilities
  • Vibration

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Control Systems Engineering.
  • Fluid Dynamics.