Research on mechanical model of metal rubber for hysteresis characteristic in the non-forming direction

Metal rubber is a kind of anisotropic material, and its mechanical properties in the non-forming direction are significantly different from those in the forming direction. According to the main deformation characteristic of metal rubber in the non-forming direction, the configuration and contact mode of wire helixes are analyzed to reveal the mesoscopic physical mechanism of its non-forming direction. Combined with the elastic deformation characteristic of wire helixes and the regularity of distribution of frictional contact points, a mechanical model of the non-forming direction of metal rubber is established, which can describe the hysteresis characteristic of its loading and unloading process under different pre-deformation. In the model the basic structural parameters of metal rubber are included which are the diameter and elastic modulus of wire, the diameter of wire helix, the relative density of material, and so on, so it is easy to explain the physical nature of the elastic characteristic and the damping characteristic of dry friction of multipoint contact of metal rubber in the non-forming direction. The experiments on metal rubber specimens with different relative densities are carried out to verify the theory model. The results show that the theoretic calculations are consistent with the experimental data. It provides the theoretical basis for studying and predicting the stiffness and damping of the non-forming direction of metal rubber. © 2015 Journal of Mechanical Engineering.