Advanced dynamic characterization and orthotropic FEM of hybrid carbon-fiber metal-matrix composite spur gears with damping sensitive resonance analysis

Abstract

Spur gears are particularly vulnerable to vibration-induced resonance, noise production, dynamic stress concentration, and early fatigue failure while running at high speeds and under cyclic loading circumstances. The dynamic performance of conventional steel gears in sophisticated transmission systems is limited by their weak intrinsic damping capability, despite their high strength and wear resistance. This work uses advanced finite element modal and harmonic response analysis to examine the dynamic behavior and vibration attenuation properties of hybrid carbon-fiber-reinforced metal matrix composite (MMC) spur gears. Six material configurations were compared, including carbon-fiber/epoxy composite, stainless-steel-reinforced hybrids (CF/Epoxy/SS316 and CF/Epoxy/SS304), aluminum-reinforced hybrids (CF/Epoxy/Al6082 and CF/Epoxy/Al1050), and SCM420H steel. Equivalent orthotropic elastic formulations obtained using rule-of-mixtures homogenization were used to represent the composite materials. Mesh-independent models with realistic elastic support and frictional contact boundary conditions were used in ANSYS Workbench 2023 R1 for finite element simulations. The Block Lanczos solver was used for modal analysis in order to obtain natural frequencies and mode shapes. Harmonic response analysis was then used to assess resonance characteristics. Rayleigh damping implementation and characterization based on Dynamic Mechanical Analysis (DMA) were used to incorporate damping features. The findings show that, in comparison to traditional steel gears, all hybrid composites have noticeably higher natural frequencies and better damping characteristics. Because of its greater specific stiffness, Composite A (80% carbon fiber + 20% epoxy resin) showed the largest natural frequency range of 47.1–56.3 kHz. The optimum balance between lightweight properties, rigidity, and vibration attenuation was demonstrated by hybrid composites reinforced with aluminum. In comparison to steel gears, Composite C2 (CF/Epoxy/Al1050) achieved the highest damping ratio (ζ = 0.08) and lowered resonant amplitudes by around 40%. Additionally, a nearly 30% decrease in root fillet stress concentration was found by dynamic stress analysis, suggesting enhanced fatigue resistance and crack suppression capacity. Aluminum-based hybrids perform better because of their reduced density, better stiffness-to-weight ratio, less rotational inertia, and increased interfacial energy dissipation. The promise of hybrid carbon-fiber metal matrix composites for lightweight, vibration-resistant, and resonance-safe spur gear applications in cutting-edge automotive and industrial transmission systems is demonstrated by the developed orthotropic finite element framework.