Passive Vibration Suppression in Truss-Type Structures with Tubular Members

Abstract

A method for vibration suppression using viscous damping material has been developed for truss structures consisting of axisymmetric tubular members of circular cross section. The vibration damping scheme calls for the construction of a structural member with two or more tubes by overlapping the end portion of adjacent tubes and bonding them together by means of a thin layer of viscoelastic material. The equations of motion for a e nite length section consisting of concentric layers of an inner tube, viscous material damping layer, and outer tube are obtained using Hamilton’ s principle. Only axial motion is considered. An exact solution to the equation is obtained and used to develop the dynamic stiffness matrix for the section. A scheme has been presented to develop a super element that consists of two or more such damping sections. The super elements have then been used to model members in a truss-type structure to study the vibration suppression in the structure. The vibration suppression is studied for a range of frequencies. A parametric study has been performed to establish the effects of thickness, loss factor, and length of overlap. The study has shown that the damping effectiveness is dependent on the coupled effects of these parameters.