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The possibility of controlling two modes of structural vibration due to earthquake excitation by considering the sloshing action in the vertical limbs of the liquid column vibration absorber (LCVA) has been explored in this paper. The structure has been modeled as a linear, viscously damped multi-degree-of-freedom (m.d.f.) system. The governing differential equations of motion for the damper liquid and for the coupled structure-LCVA system have been derived from dynamic equilibrium. The nonlinear orifice damping in the LCVA has been linearized by a stochastic equivalent linearization technique. A displacement transfer function formulation for the structure-LCVA system has been presented. The study has been carried out on a 2-d.f. example structure for which both the modes have significant contribution to the total response. The performance of the LCVA has been evaluated in the frequency domain with the base input characterized by a white noise power spectral density function and through a simulation study by subjecting the example structure-LCVA system to a recorded accelerogram. The results are compared with that of the liquid column damper and indicate superior performance of the LCVA. Furthermore, an LCVA has been designed for the example structure. [ABSTRACT FROM PUBLISHER]

The potential of the liquid column vibration absorber (LCVA) as a seismic vibration control device for structures has been explored in this paper. In this work, the structure has been modeled as a linear, viscously damped single-degree-of-freedom (SDOF) system. The governing differential equations of motion for the damper liquid and for the coupled structure-LCVA system have been derived from dynamic equilibrium. The nonlinear orifice damping in the LCVA has been linearized by a stochastic equivalent linearization technique. A transfer function formulation for the structure-LCVA system has been presented. The design parameters of the LCVA have been identified and by applying the transfer function formulation the optimum combination of these parameters has been determined to obtain the most efficient control performance of the LCVA in terms of the reduction in the root-mean-square (r.m.s.) displacement response of the structure. The study has been carried out for an example structure subjected to base input characterized by a white noise power spectral density function (PSDF). The sensitivity of the performance of the LCVA to the coefficient of head loss and to the tuning ratio have also been examined and compared with that of the liquid column damper (LCD). Finally, a simulation study has been carried out with a recorded accelerogram, to demonstrate the effectiveness of the LCVA. [ABSTRACT FROM AUTHOR]