Modeling of Folded Beam Waveguide Absorber Behavior Using Finite Element Analysis

摘要

Waveguide absorbers have been shown to be an effective low frequency damping treatment for thickwalledstructures. Previous studies have used analytical predictions to model waveguide absorber drivepoint impedances and damping behavior. The analytical damping predictions generally underestimate thedamping provided by waveguide absorbers due to simplifying assumptions that are not valid in manycases. In this study, finite element analysis is used to predict the drive point impedance and dampingbehavior of folded beam waveguide absorbers encased in damping material. The damping contributionwas measured for two absorbers attached to a thick rectangular plate, and the results were compared withpredictions made using finite element complex eigenvalue analysis. The finite element analysispredictions matched the experimental measurements much better than the analytical predictions do. Thefinite element predictions of waveguide absorber damping behavior show great promise for guiding thedesign and application of waveguide absorbers on structures.