Design of a disc-shaped viscoelastic damping material attached to a cylindrical pipe as a dynamic absorber or Houde damper

The vibration of pipes and cylindrical shells leading to noise and damage is an important engineering problem in plant systems and air conditioners, among others. To attenuate such vibration, a viscoelastic material is attached to a pipe as a damping material. Generally, the viscoelastic material covers the entire pipe to provide damping due to elongation of the material, but this requires a large amount of viscoelastic material. To overcome this problem, the approach adopted in this paper is to attach the viscoelastic material to only part of the pipe. The vibration of the pipe is then attenuated by not only the damping due to the viscoelastic material but also by the viscoelastic material acting as either a dynamic absorber or Houde damper. The disc-shaped viscoelastic material attached to the pipe is modeled as either a mass–spring–damper system or mass–damper system, and design guidelines are proposed for the material based on invariant-point theory. To assess the validity of the proposed design method, hammering tests are performed involving designed silicone attached to a pipe. The first- and second-order resonances of the pipe are attenuated by the silicone as a dynamic absorber and a Houde damper, respectively.