Abstract: The present invention is a “beam type” tuned mass damper (TMD) having beams of constrained layer viscoelastic laminate material affixed to a mounting base or directly to the host structure and a method of use. The “beam type” TMD of the present invention is able to damp several frequencies by combining beams of varying characteristics to the mounting base, such as by changing the geometrical or material properties of the constraining layers and the viscoelastic layer of the constrained layer viscoelastic laminate.

Abstract: An internally damped laminated tube comprises an outer layer and an inner layer, with a viscoelastic layer disposed therebetween. The outer and inner layers constrain the viscoelastic layer, thereby providing noise and vibration reduction through constrained-layer damping. While both the outer and inner layers act as constraining layers, the outer layer also preferably provides structural support for the tube, thus necessitating a thicker outer layer. Preferably, the outer and inner layers comprise steel. The internally damped tube according to the present invention exhibits a composite loss factor greater than four percent for ring modes occurring at vibrational frequencies between 700 and 950 Hz.