Vibration Damping of Adhesively Bonded Joints

Abstract

A study into the vibration characteristics of adhesively bonded single lap joints has been carried out to investigate the effect of joint geometry and temperature variation on overall system damping. Concepts of vibration damping are introduced and it is shown how to determine the damping of a system. The methodology of calculating the damping of even a simple bonded element in the form of a lap joint from material and geometric parameters is shown to be complex. The vibration damping of bonded joints has been extended into an experimental program using four different adhesives. These were AV119, a one-part epoxy; 9245, a structural bonding tape; 3532, a two-part polyurethane; and Hysol XEA 9359.3, a two-part structural adhesive. High-strength steel adherends were used to manufacture single lap joints of varying overlap lengths. The specimens were vibrated flexurally and the damping values calculated using the free decay method.