THE DAMPING OF STRUCTURAL VIBRATION BY THIN GAS FILMS

A theoretical and experimental investigation of the processes by which thin layers of gas trapped between surfaces of a structure may contribute to damping of structural vibrations is described. Effects of gas compressibility, inertia and thermal conductivity are allowed for in the theory. Particular attention is given to the variation of damping with gas pressure and layer thickness. The aim of the investigation was to provide results of use in the design of vibration absorbers for use in pressurized gas environments, as well as to contribute to a better understanding of the behavior of pre-existing gas layers in structures.