On the design of structural junctions for the purpose of hybrid passive–active vibration control

A theoretical investigation of wave scattering and the active modification of wave scattering at structural junctions is presented. A resonant and a non-resonant Euler–Bernoulli beam are coupled, and an external force is introduced at the junction. The external force is intended for feedforward control in order to manipulate the scattering properties at the junction. The purpose of the investigated control law is to make the junction non-reflective in the case of an incident bending wave. The control effort and the resulting power flow are investigated for different properties of the beams. By introducing damping in the resonant beam all incidence wave power is absorbed either passively, in the resonant beam, or actively, by the force. The results form the basis for a discussion of the possible benefits of using such a configuration for hybrid passive–active vibration control. The results show that for certain ratios of bending stiffness and mass the presented hybrid passive–active solution may offer advantages compared to purely passive or purely active solutions.