Fatigue life and failure mechanisms of cord-reinforced rubber composites: influence of fiber orientation, layer architecture, and matrix thicknessGłowacka, Karolina (Avtor) Małecka, J. (Avtor) Pawliczek, Roland (Avtor) Kurek, A. (Avtor) Nagode, Marko (Avtor) Klemenc, Jernej (Avtor) Łagoda, Tadeusz (Avtor) compositerubberfatigueuniaxial loadingmean valueThis study investigates the fatigue life of cord-reinforced rubber composites subjected to fully reversed three-point bending. Although nominally a bending test, the high displacement amplitudes and low specimen stiffness lead to a tension-dominated loading state due to geometric nonlinearity. The research focuses on the influence of fiber orientation (0/90° vs. ±45°) and the number of reinforcement layers on fatigue durability. It was demonstrated that traditional parameters, such as strain amplitude or maximum strain, are insufficient to describe fatigue life under non-zero-mean-strain conditions. Instead, the Smith- Watson-Topper (SWT) and Walker models were successfully employed to unify the results. The findings reveal that ±45° configurations exhibit superior fatigue life compared to 0/90° layups under strain-controlled conditions, primarily due to fiber reorientation and lower internal stress levels. Analysis using the Walker model showed that single-layer composites are more sensitive to maximum strain (γ = 0.3), whereas double-layer systems are dominated by strain amplitude (γ = 0.7) due to interlaminar shear and internal friction. Furthermore, a critical relationship between matrix thickness and reinforcement ratio was identified: increasing rubber thickness improves durability in single-layer systems but deteriorates it in double-layer composites due to weakened crack-bridging mechanisms. SEM analysis confirmed these findings, highlighting the role of fiber pull-out and interlaminar degradation. Finally, the study highlights a lack of correlation between static tensile strength and fatigue performance, underscoring the need to account for viscoelastic effects in the design of cord-rubber structures.20262026-08-24 09:45:58Članek v reviji185935sl