Bioinspired fiber-reinforced shear-stiffening elastomer with enhanced impact resistance under complex dynamic loadings

Stretchable fiber-reinforced polymers (FRPs), commonly manufactured using high-performance fibers and polymer matrices through processes such as compression molding and pultrusion, have gained widespread application in the high-end equipment manufacturing due to their high specific modulus, regulable mechanical properties, and exceptional durability. Despite these advantages, conventional FRPs often exhibit inadequate impact resistance under complex dynamic loading, limiting their broader engineering deployment. Herein, a fiber-reinforced elastomer composite, comprising a shear-stiffening elastomer (SSE) matrix integrated with high-toughness aramid fibers is reported, in which rate-dependent mechanical reinforcement is leveraged to markedly improve impact resistance. Inspired by the structural and functional characteristics of fibrous cartilage, the composite harnesses synergistic dynamic coupling between the viscoelastic SSE matrix and embedded fibers, enabling efficient energy dissipation across a broad range of strain rates and loading modes. Application experiments further validate the effectiveness of this advanced fiber-reinforced composite in Formula racing contexts, highlighting its potential for next-generation protective systems in demanding environments. Inspired by fibrous cartilage, this study developed a fiber-reinforced elastomer (SSEK) combining shear stiffening elastomers and Kevlar fibers. Exhibiting superior impact resistance and thermal stability, SSEK outperformed single-phase component and commercial counterparts in drop hammer and ballistic tests. Validated for racing sports applications, this advancement highlights the potential of high-performance shear stiffening materials. • Bioinspired Kevlar-reinforced SSE achieves exceptional impact resistance. • Composite shows 14 × higher specific energy absorption than homogeneous SSE matrix. • Coupled DIC-FEA analysis reveals fiber-matrix load transfer and interfacial failure. • Multifunctional protection with flame resistance validated in Formula racing tests.