Rainbow trapping effect, essential for flexural wave energy localization in elastic metamaterials, is typically constrained to a single mechanism with low efficiency. This study proposes a sinusoidal‐profile nonuniform metamaterial beam to achieve multipathway rainbow trapping via both band gaps and interface states. A theoretical model based on Timoshenko beam theory is developed and solved using the differential quadrature method (DQM), which accurately predicts the evolution of the first band gap in periodic nonuniform beams. The results are systematically verified by comparison with finite element simulations. Leveraging the band gap characteristics, a nonuniform metamaterial beam is designed to achieve rainbow trapping. Excitation with eight frequency‐matched segments results in distinct flexural wave energy concentration due to the band gap effect. Furthermore, a mirror‐symmetric supercell composed of unit cells with opposite geometric parameters reveals two distinct interface states. These states enable strong flexural wave localization at the corresponding interface positions when excited at the respective interface state frequencies. By combining band gap and interface state effects, an optimized metamaterial beam simultaneously achieves two independent rainbow trapping mechanisms. This study demonstrates multipath regulation beyond single‐mechanism designs, providing a basis for developing high‐performance elastic wave localizers, filters, and smart metamaterials.
Deng et al. (Thu,) studied this question.