Structural Damping by the Use of Fibrous ,Blankets

摘要

From the experimental study of the damping effect of fibrous layers, it was found that fibrous materials did providea very significant damping of structural vibrations at frequencies, and under conditions of excitation, in which thepanel responds modally.Modal analysis was applied to solve the structure-fluid coupling problem of a simply supported beam withattached fibrous layer treatments. The energy dissipated within the attached fibrous lay& was used to characterizethe damping effects of the treatments. This work was based on the implicit assumptions that no energy isdissipated at the duct boundaries and that no sound radiates from the driven side of the beam. The accuracy of thederived solutions depends on the number of terms used in the series to satisfy the boundary conditions. Therefore,if the range of frequencies of interest is increased, the number of modes included in the solution must be increasedcorrespondingly to ensure that the modal truncation error is insignificant.