Wave Propagation in Shear Beams Comprising Finite Periodic Lumped Masses and Resting on Elastic Foundation

Abstract

In this study, the dispersion of an infinite shear beam with a lumped mass connected at periodic distances and resting on an elastic foundation was examined. The effect of periodicity in the finite region of the lumped masses on wave propagation was investigated through a one-dimensional model. The dispersion relationship for Bragg scattering, which consists of one-dimensional periodic lumped masses, was derived using the transfer matrix method. Subsequently, to evaluate the effect of parameters such as the magnitude of the lumped mass and foundation stiffness on the dynamic response of the shear beam, several simulations were performed. The band frequency characteristics of the shear beam are demonstrated with respect to the variations in stiffness and mass. Using the wave-based approach, the effect of periodic masses on wave propagation in a finite region of an infinite beam was revealed. Periodic masses have been shown to have a positive effect on the displacement amplitude; in other words, a lumped mass barrier is effective in providing wave attenuation.

Keywords

• wave dispersion
• periodic structure
• lumped mass
• band gap
• wave barrier
• elastic foundation