NONLINEAR VIBRATION ANALYSIS OF ROTATING FUNCTIONALLY GRADED CNTS-REINFORCED COMPOSITE BEAMS: EFFECTS OF CNTS DISTRIBUTION PROFILES AND SYSTEM PARAMETERS

The nonlinear vibration behavior of rotating functionally graded carbon nanotube-reinforced composite (FG-CNTRC) beams is investigated with the impact of carbon nanotube (CNT) distribution patterns and system parameters. Five CNT distribution patterns are considered: Uniform Distribution (UD), Functionally Graded Λ-shaped (FG-Λ), V-shaped (FG-V), Outer (FG-O), and X-shaped (FG-X) to analyze their influence on the mechanical and dynamic properties of the beams. Utilizing Galerkin's method, the frequency ratios are determined with varying amplitudes, hub rotational radii, and volume fractions of CNTs. Statistical results reveal that the FG-Λ distribution gives the highest frequency ratio, enhancing by around 18-20% as compared to the UD configuration, while the FG-O and FG-X distributions represent intermediate improvements. The finding illustrates that a modification in the CNT volume fraction from 0.12 to 0.28 results in a significant increase in the system stiffness with increasing frequency ratios ranging from 1.36 to 2.0 at the peak amplitudes. Additionally, the effect of a hub radius (r = 0.5) also increases the frequency ratio by 6-8%, hence demonstrating the material and geometric parameters' synergy. These findings emphasize the importance of optimizing CNT distribution and system geometry for future engineering use, particularly in aerospace and energy systems