The optimum structural control method – neutral equilibrium mechanism

Traditional structure was used as an active control mechanism and structure system under the stable situation in the time history of dynamic response. In order to attain the energy dissipation, the additional applied work depends on the deformation of control elements. The new control mechanism, Neutral Equilibrium System (NES), will be introduced in this paper. NES is composed of unstable control mechanism and stable structure frame. It has advantages of all functions; a merit of active control method and it does not require the extra energy supply. The earthquake record or the histories of harmonic loading are used as input data to discuss the results of numerical simulation in investigating the stability, usability and effect of this control mechanism. The results indicate that this mechanism should be controlled thoroughly. Under appropriate control law, the control state is nearly perfect. Nevertheless, the external energy is required for control system to operate by using the control law of related displacement. Thus, NES should match with the control law of related velocity. The entire capability of active control can be performed under the condition of direct velocity and control feedback control method when no power energy is supplied.