Parametric Study of Impulse Semi-active Mass Damper with Developing Directional Active Joint

High-rise buildings can easily suffer structural damage from dynamic excitation, which can be reduced with a tuned mass damper (TMD). However, TMDs can experience detuning or large displacement of the mass block. To prevent detuning, a newly developed directional active joint (DAJ) installed for automatic decoupling between the control mass block and the structure is proposed. The switching timing of several weight ratios for this DAJ and the response weighted control law were investigated with the vector form instinct finite element method and the fourth-order Runge–Kutta method. A ten-story building under excitation of near fault and far-field seismic records as the original structure and under TMD and semi-active mass damper (SAMD) (VwnA1) control was investigated to compare the displacement reaction of the top floor, efficiency of shock absorption and change in the shock absorption effect when the basic vibration frequency of the structure was misestimated. With the SAMD, the structure’s maximum displacement reaction was reduced by 37–42%. Regardless of the structural frequency misestimation ratio, the maximum displacement and average root mean square absorption rate at the top floor was only 4%, and the detuning phenomenon had little effect on it. With the TMD, a higher or lower misestimation ratio of the structure frequency caused a worse shock absorption effect. The SAMD is less sensitive to the basic vibration frequency of the structure and can indeed prevent the detuning effect of the TMD.