Abstract：Filled rubbers have been widely used in various industrial applications, including tires, sealing materials, shock absorbers, artificial muscles and soft robotics. They exhibit complex inelastic behaviors, including a rate-dependent viscoelastic effect and a deformation-history-dependent Mullins effect. In the past, various works have been done to characterize the mechanical behaviors of filled rubber. However, most of these works were either performed at room temperature or only focused on one type of the inelastic behaviors. To overcome this limitation, in this work we performed a series of experiments to investigate the influence of temperature and strain rate on the Mullins effects and viscoelastic behaviors of a filled rubber Viton. To separate the coupled response between viscoelastic and the Mullins effects, the repeated loading-unloading tests were used to obtain the preconditioned specimens without the Mullins effect. Thus, in the same loading condition, the difference between the stress response of the virgin specimens and the preconditioned specimens is only contributed by the Mullins effect. The results show that the Mullins effect is independent on temperature and deformation rate. Uniaxial compression tests were also performed on the preconditioned specimens at different temperatures and strain rates. The results show that the viscoelastic response is significantly influenced by temperature and strain rate. At lower temperatures, an obvious strain hardening response can also be observed. The results of the stress relaxation tests demonstrate that the applied strain also affects the viscoelastic behaviors. More specifically, a large applied strain suppresses the stress relaxation of Viton. These results can advance our understanding of the inelastic behaviors in filled rubber.
2019, Vol. 40 
