Large Deformation Micropolar Theory for Cord Rubber Composites
Abstract Based on a 2nd Piola Kirchhoff type formulation, a new unipolar cord rubber composite constitutive theory is developed. It has the capability to handle the local/global effects of cord twist under both small and large deformation situations. In this context, the theory handles the coupling between stress and moment stress and associated kinematics. The development also handles several new Poisson effects which involve the coupling of both axial elongation and twist, as well as axial twist and lateral elongation. The theory incorporates both experimentally and analytically based parameters to define the various response characteristics. The analytical results involve the use of several finite element simulations to define local cord rubber response. Several elasticity/strength of materials based limiting arguments were used to define asymptotic behavior, thereby providing for a more physics based curve fit of empirical data.