Dynamic modelling and nonlinear mechanical properties of hat-shaped metal rubber

Metal rubber materials are recognized for their unique nonlinear mechanical properties, particularly as specialized vibration damping elements in harsh environments. To achieve the stiffness and damping performance requirements for multi-degree-of-freedom vibration isolation platforms, hat-shaped metal rubber (HSMR), a novel type of soft materials and structural component with multi-directional damping capabilities is designed. The dynamic model associated with nonlinear elastic spring, nonlinear viscous damper, and hysteretic coulomb damper is developed. The orthogonal least squares (OLS) algorithm is employed for parameter identification based on dynamic testing. The dynamic mechanical properties and the energy dissipation of HSMR at different densities (4.7–5.6 g/cm 3 ) and sidewall tilt angle (60°–80°) are explored using experimental and numerical methods. Based on the experimental results, a coefficient model of dynamic model is constructed for the first time in terms of density and external dimensions (sidewall tilt angle). This further facilitates the construction of enhanced universal dynamic model. The results show that the theoretical predictions of enhanced universal dynamic model are in good agreement with experimental results. The error in the predicted force range is much less than the response force of the model. This indicates that the model possesses impressive accuracy in capturing the nonlinear mechanical behavior. These researches provide an alternative theoretical support for improving the universality of the dynamic model, with the potential to positively impact related engineering applications.