Closed-cell ethylene–vinyl acetate (EVA) foams reinforced with particulate fillers can be regarded as lightweight cellular polymer composites, widely used in energy-absorbing applications where compression fatigue resistance and shape recovery are critical. Although particulate fillers are commonly introduced to enhance mechanical properties, their influence on fatigue behavior through deformation-induced microstructural changes remains insufficiently understood. In this study, the effect of biosourced silica content on the compression fatigue behavior of closed-cell EVA foams is investigated. EVA foams containing 0 to 20 wt% biosourced silica particles are manufactured while maintaining practically constant porosity (0.80) and density (0.18 g cm −3 ), allowing the intrinsic effect of filler content to be isolated. The mechanical response under cyclic compression fatigue is correlated with post-deformation microstructural observations using scanning electron microscopy and X-ray microtomography. The results show that increasing filler content from 0 to 20 wt% enhances initial stress levels and absorbed energies by a factor of ≈ 2, but increases both the dissipation ratio and residual strain by a factor 1.5 and 2, respectively. These trends are preserved upon cycling, with important decrease (resp. increase) of stress levels and absorbed energies (resp. dissipation ratio and residual strains) as the cycle number increases. Cyclic compression induces pronounced filler-dependent changes in cell wall morphology, including bending, buckling and localized damage leading to measurable changes in plastic strain accumulation: after cycling and strain recovery, the compression plastic strain rises from 0 to 0.15 when the filler content varies from 0 to 20 wt%. These deformation-induced morphological features provide insight into the mechanisms governing fatigue degradation and reveal a trade-off between mechanical reinforcement and fatigue durability using 10 wt% of biosourced silica. Overall, this work demonstrates that biosourced silica content governs the compression fatigue performance of EVA-based cellular composites primarily through its influence on the evolution of deformation-induced cell wall morphology. The present results provide mechanistic understanding and practical guidance for the microstructural design of lightweight and durable cellular composite materials. • Biosourced silica content governs the compression fatigue behavior of EVA cellular composites. • Increasing filler content enhances mechanical properties while altering fatigue resistance and shape recovery. • Cyclic compression induces filler-dependent, deformation-induced cell wall morphology. • A trade-off between mechanical reinforcement and fatigue durability is identified.
Aimar et al. (Fri,) studied this question.