Unveiling a new shear stress transfer mechanism in composites with helically wound hierarchical fibres

The mechanical performance of reinforced composites is strongly influenced at different scales by the stress transferred matrix-fibre interfaces and any surface where material discontinuity occurs. In particular, response elastomeric reinforcement composed cords with helically wound fibres heavily compromised fatigue delamination phenomena occurring cord-rubber as well ply interfaces, since rubber polymeric matrices are mainly vulnerable to accumulation deviatoric energy due shear stresses across surfaces. Despite large diffusion in a vast field applications mature knowledge their behaviour, some key aspects underlying failure mechanisms still partially unclear. For example, amplification strain localization often difficult predict means analytical solutions averaging techniques that usually conceal gradients. this work, we analyse coupling between torsional tensile loads twisted cords, which adopted many cases reinforce rubbers tire applications. We provide model characterized an enriched cord-matrix interplay able theoretically explain actual distributions responsible for onset fatigue-guided experimentally observed these composites. demonstrate assumption monoclinic/trigonal behaviour hierarchical strands allows estimate, formulas homogenization approach, hitherto neglected matrix-reinforcement interface. These neighbouring regions, leading post-elastic events.