Abstract
The mechanical properties of rubber vulcanizates under finite deformation have been investigated both theoretically and experimentally. There remain many unsolved questions in the analysis of the elastic properties of rubber vulcanizates, however. These practical examples can be observed in the Mooney-Rivlin plot which gives nonlinear curves resulteting in difficulties in the analysis.
In general, the tensile properties are revealed only by the simple extension test which does not give information enough to analyze the mechanical behavior. This may be attributed to the fact that the range of elastic deformation is large and the mechanical behavior is nonlinear. These defects may be improved by using biaxial tensile measurement.
In the present paper, the results of biaxial tensile measurement on NR vulcanizate are reported. The energy functions such as ∂W/∂I1 and ∂W/∂I2 also are estimated as a function of invariants of deformation tensor, I1 and I2.
