<title>Design considerations for active constrained layer damping treatments</title>

Abstract

Active constrained layer damping consists of either replacing or augmenting the constraining layer for a viscoelastic material with piezoceramic actuators in an attempt to improve vibration suppression properties by synergism between passive and active damping techniques. An important question in such configurations is whether the reduction in actuation ability of the piezoceramic on the beam due to a relatively soft viscoelastic layer is compensated for by enhanced passive damping due to increased shear in the viscoelastic material. Some tradeoffs between pure passive, pure active control, and active constrained layer damping are discussed here. Velocity feedback and LQR are investigated. Several authors have researched and developed formulations for active constrained layer damping techniques. The approach presented here differs from most in that it employs an energy principle for the equations of a beam with partial active/passive constrained layer damping transients. An offshoot of this is the thickness of the viscoelastic layer can be arbitrarily small (even zero), thus opening up the possibility of simulating the realistic design problem where the optimal sizing, length, and thickness of a treatment is subject to a total thickness restriction. The results show that the active constrained layer damping treatment provides better vibration suppression than passive damping treatments, and it even out performs pure active control for low-gain applications.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.