Dynamic response of identical adjacent structures connected by viscous damper

In this paper, the dynamic behavior of two identical adjacent structures connected with viscous dampers is investigated under base acceleration. The base acceleration is modeled as harmonic excitation as well as stationary white-noise random process. Each adjacent structure is modeled as a two-degree-of-freedom system. The governing differential equations of motion of the coupled system are derived and solved for relative displacement and absolute acceleration responses. A parametric study is conducted to study the influence of important system parameters on the response behavior of damper connected structures. The important parameters considered are excitation frequency, mass ratio, and stiffness ratio of the structure. It is observed that the viscous damper is quite effective in controlling the dynamic response of identical connected structures. For a given coupled structure and excitation, it is found that there exists an optimum value of damping coefficient of damper for which the peak responses under harmonic excitation and the mean square response quantities under stationary white-noise excitation attain the minimum value. The close-form expressions for optimum parameter and corresponding response are derived for an undamped system. Finally, it is observed that the damping ratio of the connected structures does not have noticeable effects on the optimum damper damping. This implies that the proposed close-form expressions of undamped structures can be used for the damped connected structures as well. Copyright (c) 2013 John Wiley & Sons, Ltd.