Dynamic Analysis of Elastomers

Abstract

This paper deals with constitutive modeling of elastomer, which is used in underwater applications. The assembly is a solid model which consists of three different materials Aluminium, Ceramic and Elastmer. All elastomers will be modelled as hyper elastic material. Hyper elasticity refers to materials which can experience a large elastic strain that is recoverable.The primary focus of this paper is to evaluate the material parameters of a polymer using Mooney Riviln strain energy density function. For this it requires uniaxial stress-strain data and optimization techniques to find Moony-Rivilin constants. INSTRON machine is used for stress-strain data of a chosen polymer and MATLAB tool is used for optimization. The geometric model of the assembly is imported into the GUI through a Parasolid file to Patran Software. For non-linear structures like this assembly model, hexahedron element was taken for meshing. The three sets of material properties were given to polymer in this assembly. The appropriate forces and boundary conditions were given to the assembly and Dynamic analysis performed. The harmonic response of the assembly model at the peak frequencies in the range, 1Hz to 1500 Hz for varying material parameters of polymer, i.e. two, five, nine Mooney-Rivilin Constants studied for 1 mm harmonic displacement. The peak responses have been identified and the stresses have reviewed at those peak frequencies to predict the dynamic behavior of the assembly and are observed to be within the design limits.