Seismic resilient steel substation with BI-TMDI: A theoretical model for optimal design

The based-isolation with tuned mass damper inerter (BI-TMDI) is utilized to enhance the seismic response of steel High-voltage substation switches mounted on frame (SMF). An analytical model with three degree-of-freedom was explored for the optimization analysis and seismic design. Firstly, the displacement variance of this SMF-BI-TMDI system in the whole frequency spectrum was obtained, using statistical Cauchy's residue theorem, which provides an explicit expression of the optimization objective function. Further, a comprehensive parametric analysis was performed, covering a wide spectrum of influential factors. Subsequently, the effectiveness of the proposed analytical model was confirmed by time history response analysis of prototype structures subjected to an ensemble of earthquake motions. The model was also compared with conventional analytical models for structural seismic optimization, showing obviously improved accuracy. This innovative control method and optimization analysis in BI-TMDI enlighten its potential with enhanced vibration control effect for protection of steel substation under earthquake motions.