Use of microcellular foam materials in constrained layer damping treatments

Constrained layer damping (CLD) treatment is a widely used surface damping treatment for vibration and noise control. In this paper, two feasibility studies were conducted using microcellular foam in CLD applications. The first study explores the feasibility of using modified polyethylene teraphthalate (PETG) microcellular foam as a damping material. Two foam configurations were tested: uncompressed (regular) and compressed foam. The second feasibility study evaluated damping performance of CLD with microcellular foam as a standoff layer. Results of the feasibility studies show that the loss factor of PETG foam with densities from 42 kg/m(3) to 240 kg/m(3) is in the range of 2% to 8%. In addition, there is no significant difference in loss factor between the uncompressed and compressed foams. Also, use of microcellular foam as standoff layer can reduce vibration amplitude up to 80% with only a 2% to 3% weight penalty.