Influences of coupler consisting of rotational stiffness and mass on wave propagation and mode localization in simply supported multispan beams

摘要

The influences of coupler on wave propagation and mode localization in simply supported multispan beams with couplers consisting of lumped rotational stiffness and mass on supports are studied. A transfer matrix equation governing the vibrational wave propagation in the simply supported multispan beams with couplers is newly derived and simplified. The eigenvalue of the simplified transfer matrix show that the larger stiffness or the larger mass of coupler makes the internal coupling between spans weaker and so it makes the system more sensivive to mode localization. As the wave frequency or the eigenvalues of the system increases, the mass effect is increased while the stiffness effect is decreased. In a case considering the large stiffness and mass at the same time, there is a region with relatively wider passbands and narrower stopbands having small attenuation rates and the normal modes in it become delocalized ones. As an example structure, simply supported two span beam with a coupler at the mid-span is considered.