Accession Number : AD0761742

Title :   Caracteristiques Acoustiques d'un Materiau Viscoelastique (Acoustic Characteristics of a Viscoelastic Material),

Corporate Author : CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE MARSEILLE (FRANCE) CENTRE DE RECHERCHES PHYSIQUES

Personal Author(s) : Bonsignour,D.

Report Date : 12 FEB 1970

Pagination or Media Count : 10

Abstract : After having briefly given the fundamental equations of visco-elasticity, the author describes two experimental methods of study of the dynamic behavior of a solid polymer such as polymethyl methacrylate. The phase of the steady-state wave, which propagates along a bar excited by an oscillator, is measured; this phase is a function of the velocity and of the attenuation of the progressive waves. By means of these quantities, the real part of complex modulus and loss factor can be determined. The experimental results are in a range of frequencies of 2 to 60 kHz and at temperatures between -40 to +50C. A resonance flexural method permits the extension of the curves down to 10 Hz. By means of these experimental results, the behavior of the material over a great range of frequencies and temperatures can be predicted and a relaxation spectrum determined. The results of this work show also a beta-transition at 20C. (Author)

Descriptors :   (*POLYMERS, ACOUSTIC PROPERTIES), ACRYLIC RESINS, TEMPERATURE, RELAXATION TIME, NUMERICAL ANALYSIS, FRANCE

Subject Categories : Plastics

Distribution Statement : APPROVED FOR PUBLIC RELEASE