Coupled axial-torsional behavior of cylindrical elastomer bushings

Elastomer bushings are important components in a vehicle suspension system to isolate vibration. The purpose of the work is to present experimental and computational studies of cylindrical bushings subjected to axial, torsional and coupled axial-torsional deformation modes. The experimental results show that the relationship between the forces and moments and their corresponding displacements and rotations are nonlinear due to the nature of the elastomer material. When an axial deformation is superimposed on a torsional deformation, a nonlinear coupled response exists; the torsional moment initially decreases and then increases with increasing axial deformation. This nonlinear coupling effect for small superimposed deformations is not well predicted computationally when modeling the bushing using common constitutive material laws in a commercial finite element package.