Evaluation of constitutive model parameters of elastomeric materials using uniaxial tensile tests

The ability of elastomers to withstand very large strains (of beyond 500%) without breakage or permanent deformation makes them an ideal material for many applications, including, but not limited to, aerospace, medical, and automobile industries, bridge bearings, seismic isolation, and supplemental dampers. It is essential for design purposes to simulate accurately the response behavior of elastomers under various loading conditions. Given the nonlinear stress-strain relationship in an elastomeric material, a hyperelastic model, instead of Hooke's law, must be employed in stress analysis of the material. The literature includes a variety of constitutive hyperelastic models for elastomeric materials. However, choosing a suitable constitutive model that simulates the elastomer stress-strain behavior under different loading conditions is challenging. This paper examines the effectiveness of various hyperelastic models of which the constant model parameters have been evaluated using the results of a standard uniaxial tensile test conducted at different strain values. The model parameters are evaluated through a curve fitting technique performed by MSC-MARC, a commercial finite element software program. A thorough examination of the efficiency and accuracy of various hyperelastic constitutive models at different strain ranges shows that the Neo-Hooken and Arruda-Boyce are suitable models for the range of small deformations, and the Ogden and Yeoh models are suitable for a wide range of deformations.