Research on Constitutive Model of Stiffness and Damping of Nitrile Butadiene Rubber

In order to establish an accurate constitutive model of NBR, the dynamic mechanical properties of NBR were described by the hyperelastic-viscoelastic model. The stress–strain, storage modulus, loss modulus and other data of NBR material in the range of low, medium and high strain rates were obtained by static compression test, dynamic sweep frequency test and SHPB test. Finally, the hyperelastic model of NBR and the viscoelastic model based on 5-order Prony series were obtained by genetic algorithm. Taking a certain type of Marine shock absorber as the object, the static stiffness, dynamic stiffness and damping, impact stiffness were obtained through tests, and the simulation under the same working condition was carried out in ABAQUS. The simulated stiffness error was less than 10%, and the simulated damping ratio error was less than 15%. The results show that the constitutive model of NBR based on this method not only has a unified constitutive model expression under a wide range of strain rate loading conditions, but also can accurately describe the elastic and damping dissipation capacity of rubber.