Figure 10. Frequency responses and w 1 – w 2 plots of Branch F and Branch H (Table 2) in Case C (Table 1) when the base acceleration is 10 m/s 2 . (a,b) Show sweep responses, stroboscopic points, and HBA solutions of Beam 1 and Beam 2, respectively. Stable and unstable HBA solutions are plotted by the solid line and dot-dashed line, respectively. The region in gray color represents the disconnected frequency bandwidth of Branch F due to instabilities. (c–e) Are the w 1 – w 2 plots of Branch F at 19 Hz, Branch H at 22 Hz, and Branch F at 30 Hz, respectively. In (a,b) , the triangle markers indicate the bifurcation points as follows: sn saddle-node bifurcation, sb symmetry-breaking bifurcation, ns Neimark–Sacker