Structural and dynamic performance of aluminum–alumina functionally graded mono-leaf springs

Abstract This study evaluates the structural and fatigue performance of mono-leaf spring. Two materials are used, the first one is 50R steel and the second is aluminum–alumina functionally graded materials (FGMs) with power-law indices of k = 0.2, 0.5, 1, 2, 5, and 10. The finite element analysis and fatigue-life assessment are used. Modal, static, and fatigue assessments were performed to investigate the effects of material gradation on natural frequencies, stress distribution, strain energy, factor of safety (FOS), margin of safety (MOS), weight reduction, and fatigue behavior. The results showed that all FGM configurations exhibited higher natural frequencies than steel because of their superior stiffness-to-weight ratios, indicating improved dynamic stability. Static analysis revealed only a slight increase in maximum von Mises stress with increasing power-law index. Although steel provided the highest FoS and MoS values, the FGM models demonstrated satisfactory structural performance, with the k = 0.5 configuration offering the best balance between strength and safety. Significant weight reduction was achieved because of the lower density of the aluminum matrix. Ceramic-rich FGMs ( k = 0.2 and 0.5) exhibited higher energy than steel, indicating enhanced energy absorption capability. Fatigue analysis based on Basquin S–N curves showed improved low-cycle fatigue performance for ceramic-rich FGMs, whereas 50R steel maintained superior resistance in the high-cycle fatigue regime.