A Visco-Hyperelastic Constitutive Model to Characterize the Stress-Softening Behavior of Ethylene Propylene Diene Monomer Rubber

Uniaxial and biaxial cyclic tensile tests stress relaxation were performed on the ethylene propylene diene monomer (EPDM) material to investigate its stress-softening effect. The experimental results reveal that EPDM presents a significant Mullins effect during stretching processes. Furthermore, it is found deformation of does not return zero simultaneously with stress, due viscoelasticity material. Therefore, this study combines pseudo-elasticity theory viscoelastic propose visco-hyperelastic constitutive model. proposed model used fit analyze uniaxial test comparison conducted corresponding hyper-elastic show in good agreement data superior model, especially when comes unloading process. This work conducive accurately characterizing behavior rubber-like materials at large deformations can provide some theoretical guidance for their widespread application industry.