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 s tudies were conducted using microcellular foam in CLD applications. The fir st study explores the feasibility of using modified polyethylene teraphthal ate (PETG) microcellular foam as a damping material. Two foam configuration s were tested: uncompressed (regular) and compressed foam. The second feasi bility study evaluated damping performance of CLD with microcellular foam a s a standoff layer. Results of the feasibility studies show that the loss f actor 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 microcel lular foam as standoff layer can reduce vibration amplitude up to 80% with only a 2% to 3% weight penalty.