**Table 1.** Structural natural frequency.

### **4. Seismic Response Law of Roof Structure under Different Seismic Arrays**

To facilitate the analysis of the seismic excitation response of the roof frame within the ring-cable structure of the gymnasium, the key structural components were numbered. As the central grid beams cover the longest span with the largest internal force value and displacement amount, they were selected as the research object. The numbers of grid beams and beam nodes are shown in Figure 5, where B represents the grid frame beam, J represents the node, X and Y, respectively, stand for the EW direction and SN direction. The numbers of struts and cables are shown in Figure 2.

**Figure 5.** Schematic diagram of roof grid beams and tip nodes. (**a**) Grid beam numbers; (**b**) number of grid beam nodes.
