Determining the Dynamic Bulk Modulus and the Elastic-Loss Factor of Polymers from Acoustic Measurements
DAVID W TAYLOR NAVAL SHIP RESEARCH AND DEVELOPMENT CENTER BETHESDA MD SHIP ACOUSTICS DEPT
Pagination or Media Count:
A dynamic measurement technique is presented for determining the bulk modulus and the associated-loss factor of elastomeric and plastic materials. A resonant water column is used from which stiffness and damping are determined by the resonance frequency and the bandwidth of its resonance curve. A SAMPLE IS INSERTED INTO THE WATER COLUMN AT A PRESSURE MAXIMUM, AND THE RESONANCE FREQUENCY AND THE BANDWIDTH OF THE SYSTEM ARE MEASURED. The difference in the resonance frequency and the bandwidth of the water column without and with the sample present is then used to calculate the real component of the bulk modulus and the loss factor of the sample. Experimental results for various materials are presented which verify the theory.
- Elastomers and Rubber