MECHANICS OF VISCOELASTIC COMPOSITES.
Abstract
An apparatus was developed to measure the dynamic mechanical properties of foamed materials filled with a viscous fluid, over a frequency range from 0.002 to 200 Hz. It has been tested using two model viscoelastic materials over the temperature range -50C to +100C. Measurements were then made on various foam/fluid systems including rubber latex, polyether and polyester foams filled with air, glycerin, silicone oil and water. The Gent-Rusch theory has been modified to take into account inertia effects, damping in the matrix material itself, and special features of the test-piece assembly. The modified theory is shown to describe the measurements successfully over the entire frequency range employed. Stress-optical coefficients have been determined for lightly-cross-linked samples of cis- and trans-polyisoprene, swollen to a high degree in a variety of non-polar solvents. A strong dependence on the geometrical asymmetry of the solvent molecule has been observed. Solvents with long straight molecules gave large values of the stress-optical coefficient whereas those with compact symmetrical molecules gave minimum values. This effect is attributed to short-range orientational order, due to packing effects in a molecularly-anisotropic medium. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1969
- Accession Number
- AD0690612
Entities
People
- Alan Neville Gent
- N. C. Hilyard
- S. V. Kanakkanatt
Organizations
- University of Akron