Determination of damping ratios of lightly-damped structures

This article describes the outcome of the study carried out to measure the damping ratios of two lightly-damped plate structures. A number of excitation techniques (like impact, shaker and acoustic excitation) have been tried. The review of literature survey shows that very little study has been done in the area of determination of damping ratios of lightly-damped structures. If proper precautions are not taken, the values of damping ratios that are obtained may grossly be different from the true values. The half-power method and decay method of determining damping have been adopted. The need for FFT zoom analysis in the determination of damping ratios of lightly damped structures has been stressed.