Phenomenological Elastomechanical Behavior of Rubbers over Wide Ranges of Strain

Abstract

Relationships have been developed which permit a relatively good description of the elastomechanical behavior of natural rubbers over the full range of deformations. These relationships were obtained by development of a general relationship set forth by Mooney. A stress function was obtained from which principal stresses may be evaluated for any given set of compatible strains. This theory was tested by applying it to experimental results of Treloar. It is demonstrated that by the insertion of relatively simple ``exponential type'' functions, a very good fit was obtained over the whole range of Treloar's data. In this form, the properties of natural rubber can be described by three parameters, A, B, and β. It has been found (to be demonstrated in a later paper) that there are unique relationships between A and β, B and β, and between β and rubber hardness for a range of natural rubbers from pure gum vulcanizates to the hardest of commercial natural rubbers.