Frictionally damped fasteners and methods of manufacturing the same

Abstract

A method and system for increasing damping capacity in a mechanical fastener by utilizing dry friction between individual wires of a sheathed rope is disclosed. For metal fasteners, the sheathed rope is inserted loosely into a thick-walled metal tube. The tube is then rolled to reduce the tube diameter, thereby uniformly embedding the rope into the tube material. The tube is then subjected to either cold or hot forming. After forming, the fastener blank may be threaded. For composite or plastic fasteners, the sheathed rope includes insert locators attached to the sheathing. The sheathed rope having the insert locators is placed in the mold cavity prior to the polymerizable material being injected into the mold. Regardless of the embodiment, the resulting fastener has increased damping due to the dry inter-wire friction within the embedded rope which develops between the surfaces of individual wires upon dynamic loading of a fastened joint.

Dependencies are inferred from the claim text.