Analytical and experimental characterization of extensional damping in single lap viscoelastic adhesive joints

Abstract

This paper describes the measurement and prediction of the damping characteristics of the single lap adhesive joint. The experimental technique used is an extensional vibration test and the theoretical analysis used is the finite element implementation of a strain energy method. A simple "mechanics of materials" analysis is also included for comparison. The experimental technique and analytical results both show that the loss factor increases with increasing frequency, but the measured damping is up to 400% higher than the finite element prediction. This difference may be due to the fact that the actual thin film properties of the adhesive are not the same as the bulk properties used in the predictions. The experimental results show that the highest damping was obtained for thin, short adhesive layers. Nomenclature interface area along the joint cross sectional area of the adherend width of adherend and adhesive viscous damping constant critical damping energy dissipated per cycle Young's modulus of element Young's modulus of adherend shear modulus of element shear modulus of adhesive