Damping of Layered and Jointed Beams with Riveted Joints

Abstract

The present investigation highlights the effect of interfacial slip on the damping of layered cantilever beams jointed with rivets undergoing free vibration. The inclusion of mechanical joints bears a strong influence in the overall system performance and behavior, particularly the damping level of the structures. In fact, the damping and its improvement in machines or structures are one of the biggest challenges to the practicing engineers. Usually, such structures inherently possess low structural damping necessitating the introduction of additional measures to improve their damping characteristics in order to control the harmful effects of vibration in normal operating conditions. Monolithic structures can be used as an alternative, but unfortunately these are very poor in damping capacity and are not cost-effective. One of the techniques used in the present problem for improving damping is fabricating these structures in layers by means of riveted joints. The incorporation of such joints is the major source of energy dissipation through frictional effects associated with relative shear displacements at the interfaces of the various structural members. Most of the damping in built-up structures is thus attributed to micro-slip at the interfaces.The contribution of the micro-slip on the overall system damping is always significant in spite of its low magnitude.