Optimization of Graphene Oxide in Silica-Filled Solution-Polymerized Styrene-Butadiene Rubber: Constitutive Modeling and Verification Using Finite Element Analysis

Graphene oxide (GO, 0–6 phr) is incorporated into silica-filled solution-polymerized styrene-butadiene rubber (SSBR) to fabricate hybrid filler-reinforced composites for tire tread applications. Tensile/compression tests and dynamic mechanical analysis (DMA) characterize the mechanical properties and filler dispersion. Hyperelastic constitutive models coupled with finite element analysis (FEA) predict and verify the hybrid systems' performance. Results show GO forms strong interfacial interactions with SSBR and silica, improving filler network dispersion. The 3 phr GO composite exhibits 19.72% higher tensile strength and 19.87% greater elongation at break than the GO-free sample. Among Neo–Hookean, Mooney–Rivlin, Yeoh, and Ogden models, the Ogden model (N = 3) shows optimal fitting accuracy (R² = 0.9954 for uniaxial tensile, R² = 0.9995 for equibiaxial tensile). The Young's modulus from fitted parameters agrees well with experimental results. FEA simulations based on the optimized model yield stress–strain curves and maximum principal stress distributions in excellent agreement with experiments. This work determines the optimal GO loading and provides theoretical support for high-performance rubber composite design.