An experimental investigation on damping with multilayered aluminium riveted and cantilevered structure

The present investigation highlights the effect of interfacial slip on the damping of layered cantilever beams jointed with rivets undergoing free vibration. A lot of experiments have been conducted on a number of specimens with connecting rivet of various diameters, length and thickness to study its effect on the damping capacity of the layered and jointed structures and to establish the authenticity of the theory. Intensity of interface pressure, diameter of the connected rivet, length and thickness of beam, number of layers, kinematic coefficient of friction at the interfaces and frequency and amplitude of excitation are found to play a major role on the damping capacity of such structures. This design concept of using layered structures with riveted joints can be effectively utilized in trusses and frames, aircraft and aerospace structures, bridges, machine members, robots and many other applications where higher damping is required. Riveted joints are often used to fabricate assembled structures in machine tools, automotive and many such industries requiring high damping. For a particular specification of the beam with thickness ratio 1.0, overall beam thickness 6 mm, and diameter of rivet 10 mm excited at 0.5 mm. Due to the incorporation of joints, it is estimated that the damping capacity increases approximately by 125 to 130 % , whereas their stiffness decreases by 15% to 22% only. When the rivet diameter Increases from 8 to 10 mm logarithmic decrement Increases by 13.26%.