Numerical and Experimental Study of Flexural Wave Band Gaps of Periodical Locally-Resonant Beams With Suspended Separated Force and Moment Resonators

In this paper, flexural vibration in a locally-resonant (LR) beam with periodically attached separated force and moment beam-like resonators is investigated theoretically and experimentally. The relationship between the distance parameter and the band structure of an Euler-Bernoulli beam with proposed locally resonators is provided using the transfer matrix theory. The frequency response functions of finite periodic systems are calculated with the finite element method over a range of different parameters of the resonators. Finally, we use LR beam specimens with separated force and moment resonators mounted on a free-free host beam for experimental measurements of the vibration transmittance. The experimental results show a good agreement with those of the theoretical and numerical except some small discrepancies at high frequencies. Our study confirms that the bandwidth of band-gaps will become wider with the increasing of the distance parameter until it reaches its peak, which provides an effective way for LR periodic structures with resonators to obtain broad band-gaps in low-frequency range, and makes the structure had potential applications in the control of vibration and wave propagation in flexural beams.