Structural modification based analysis and design of tuned mass dampers

Abstract

This article discusses the design of tuned vibration absorber for structures. A central notion in the identification of the parameters of a tuned mass damper (TMD) absorber for MDOF systems is that of modal mass of the original structure. The modal mass, as it is well known, is associated with the mode of vibration of the original structure whose frequency is required to be absorbed. The estimation of the modal mass can be achieved by either using a mass, stiffness, and damping model of the structure or, for an existing in service structure, from experimental modal analysis. In both of the above cases inaccuracies are introduced due to modeling errors and experimental noise. This article sets the theory of TMD in the context of structural modification. This enables the design of TMD by using only the frequency response function of the primary system without taking into consideration the original mass or modal mass. The theory developed herein is for one degree of freedom undamped primary vibrating system. The proposed structural modification based methodolgy of designing TMD is demonstrated on a specific single degree of freedom vibrating system.