ABSTRACT
Stress-strain measurements are reported for compressed bonded disks and inflated membranes of gum natural rubber. The compression measurements were compared to various models. In the inflation measurements, the strain distribution was determined for various pole biaxial strains. The radial strain was found to be nearly constant over the entire surface, while the circumferential strain falls to zero at the edge. There are many practical applications of bonded rubber disks between rigid plates, also many applications of inflating membranes. Strain crystallization of the natural rubber can exert an influence. Although the strains in the present experiments were too small, it is likely that crystallization transpires during Treloar's measurements at higher strains. Since the strain energy function used in the modeling efforts excludes this effect, discrepancies between theoretical predictions and Treloar's results may be expected for higher strains. The strain distribution was also calculated using finite elements. The experiment results and the modeling were in good agreement.
