Hyper‐viscoelastic characterization of highly filled rubber compound: Extending approach for geometrical defect analysis

Abstract

The work provides insight into the hyper‐viscoelastic characterization of highly filled rubber compound with low structured carbon black, further examining geometrical defects using finite element (FE) simulations. The complete force‐extension behavior and stress relaxation (various strain levels [10%–100%]) in a uniaxial state of stress are reported. The extension at break is reduced by more than 42% for geometrically defective specimens. The breakage of filler–filler interaction attains equilibrium at 75% strain in stress relaxation experiment. Beyond this, the relaxation depends majorly on polymer chains. Hyperelastic material models, namely Ogden, Yeoh, and Arruda–Boyce, are chosen for the present investigation. A Prony series is used for capturing the viscoelastic properties of relaxation times. The combined utilization of the Ogden law and the Prony series in FE simulations provides an excellent match in capturing the experimental features. The effect of geometrical defects is illustrated via solving a series of numerical as well as experimental results. The simulated shape/profile changes such as necking and elliptical formation are excellently comparable with experimental results. Strain localization study shows the stress concentration zone and early prediction of failure location. The methodology presented is potentially crucial for understanding and simulating engineering rubber product's complex structures in general.