Shape Index to Describe Stress—Strain Curves of Filled Elastomers

Abstract Simple mechanical models illustrating the behavior of viscoelastic material which exhibit yield, were used to define a shape index to describe the stress-strain curve of filled elastomers. Thus a numerical index was found to be useful to characterize relatively small changes in the shape of stress-strain curves of the above materials. It can be also used as a measure of the linearity of the material response in the whole range of deformation.