Characteristics of liquid column vibration absorbers (LCVA) - II

An investigation is undertaken into the bidirectional configuration of the liquid column vibration absorber (LCVA), in which the horizontal and vertical columns may have different cross-sectional areas depending on performance requirements. The bidirectional LCVA appears as a rectangular annulus in plan and mitigates the vibrations of a structure free to move in the horizontal plane by the gravitational restoring force acting on displaced LCVA liquid, energy dissipation occurring through the viscous interaction between the rigid LCVA container and the LCVA liquid, as well as transition effects which occur as the liquid moves between the horizontal and vertical columns of the LCVA. The performance of various configurations of the bidirectional LCVA are studied experimentally when installed on a primary structure subjected to external sinusoidal loading. A theoretical model of the response of the primary structure is presented in which the LCVA is modelled as an equivalent solid mass vibration absorber (SMVA) and is found to agree with experimental data. The parameters which allow optimization of the performance of the bidirectional LCVA are investigated, and methods allowing their prediction and control are also presented.