Free Vibration of Hemp Fiber‐Reinforced Laminated Composite Curved Beams Using Generalized Differential Quadrature Method

ABSTRACT In recent years, increasing environmental awareness has stimulated growing interest in natural fiber‐reinforced composites (NFRCs) due to their eco‐friendly composition, biodegradability, low cost, lightweight, and satisfactory mechanical properties. Among natural fibers, flax, jute, and hemp are commonly used for composite applications. This study investigates the free vibration behavior of laminated composite curved beams reinforced with hemp fibers in both pure and hybrid forms with glass and carbon fibers. The governing equations are derived based on the principle of virtual work, and spatial derivatives are calculated using the Generalized Differential Quadrature (GDQ) method. Effects of hybridization, stacking sequence, curvature ratio, and boundary conditions on free vibration behavior are examined. Experimental vibration tests are conducted for nine stacking sequences of straight composite beams, showing good agreement with the numerical results. Experimental results indicate that the carbon‐hemp hybrid composite beam (CHC) (C: carbon, H: hemp) has slightly higher natural frequency values than the carbon‐glass hybrid composite beam (CGC) (G: glass). For curved beams, CHCHC and CHHHC configurations exhibit the second‐highest natural frequency values after the pure carbon fiber‐reinforced composite beam (CCCCC). The results indicate that, when properly optimized, hemp‐based hybrids can be a sustainable alternative to glass fiber‐reinforced composites for vibration‐sensitive applications.