Low-frequency damping of metal panels in ambient air

Mathematical models of structural dynamics are widely used and applied in many branches of science and engineering, and it has been argued that many of the shortfalls with these models are due to the fact that the physics of joint dynamics are not properly represented. Experimental analyses are, therefore, widely used to underpin any work in this area. The most renowned model for predicting the damping resulting from air pumping is based on a significant quantity of experimental data and was generally developed and applied to high frequency vibrations of jointed or stiffened panels. This publication applies this model to low frequency panel vibrations by assessing the accuracy of the model for these systems. It is concluded that the theoretical model for high stiffness joints, although generally over approximating the damping magnitude, gives a good conservative estimate of the increase in damping due to air pumping for low frequency vibrations.