The specimen optimization for the equibiaxial test of elastomers

Elastomers have an important role in a many engineering applications today [1]. A need of exact description of their mechanical properties rises still more often. Therefore it is not enough to test these materials only in uniaxial tension test, but for complete characterization of them it is necessary to test elastomers in other deformation modes, as in equibiaxial tension and in pure shear [2]. These methods are not standardized. The optimization of the shape of specimen for the equibiaxial tension test is the object of this work. The bubble inflation technique [3] is used for the equibiaxial loading of the specimen of elastomer. The flat specimen of the elastomer is inflated through the circular ring in this method [4]. The influence of the specimen thickness and the ring diameter on the test results was evaluated and the optimal specimen dimensions were chosen