Vibration response of constrained viscoelastically damped plates: analyses and experiments.

Abstract

The frequency response analysis of several constrained viscoelastically damped plates were performed with modifications to account for the frequency dependent properties of viscoelastic materials (loss factors and shear modulus) using MSC/NASTRAN. A modal strain energy approximation method was also applied to each plate. Comparisons of the frequency response analysis to the modal strain energy method were made for each plate structure. The experiments were performed on the plates to establish the base line data for the comparisons. The modal strain energy method frequency response plots showed good agreement with the frequency response analysis method plots for all plate structures analyzed. Plate structures with fewer natural frequencies in the frequency range investigated showed better agreement between the two prediction methods than the structures with more natural frequencies. The experimental data for the plate analyzed indicate less damping than calculated by either of the finite element prediction methods. The experimentally determined natural frequency modes were well approximated by both of the finite element prediction methods.