## 4 Overview of Pseudo-Dynamic Testing and Result Analysis
### Experimental Results and Analysis
#### 4.5.2 Maximum Seismic Response Load and Displacement  
The test frame with no reinforcement applied (PD-FR) was subjected to pseudo-dynamic testing at an input seismic ground motion of 200 cm/s\({}^{2}\); the test frame retrofitted with NBSD-WSCS (PD-NBSD-WSCs) was subjected to pseudo-dynamic testing at input seismic ground motions of 200, 300, 400, and 500 cm/s\({}^{2}\), and the measured maximum response load and displacement were compared with respect to the failure mode and seismic damage, as shown in Table 9. In the test frame with no reinforcement applied, i.e., PD-FR, the maximum seismic response occurred at 272.5 kN with a displacement of 70.2 mm when the input seismic ground motion was 200 cm/s\({}^{2}\). At around 3.5 s, where the maximum seismic response occurred, the test frame finally underwent shear failure. Here, the degree of seismic damage was considered to correspond to _Collapse_ in accordance with [PERSON] [47] and [PERSON] et al. [48]. In the test frame retrofitted with the NBSD system (PD-NBSD), the maximum seismic response occurred at 419.5 kN with a displacement of 23.8 mm when the input seismic ground motion was 200 cm/s\({}^{2}\). The degree of seismic damage was insignificant compared to PD-FR at the same seismic ground motion. At 300 cm/s\({}^{2}\), the maximum seismic response occurred at 592.9 kN with a displacement of 46.6 mm, and the corresponding degree of seismic damage was determined to be _Small_ in accordance with JBDPA [47] and [PERSON] et al. [48]. These results confirmed that, given that the test frame with no reinforcement applied underwent shear failure, the reinforcement using NBSD led to a failure mode shift from shear to flexural failure, demonstrating the significantly improved energy dissipation capacity of the NBSD-based seismic control system developed in the present study. When the input seismic ground motion was 400 cm/s\({}^{2}\), i.e., when a large-scale earthquake was assumed, the maximum seismic response occurred at a shear stress of 711.9 kN with a displacement of 85.6 mm, the corresponding degree of seismic damage was determined to be _Large_. These results verify the seismic retrofitting performance of the NBSD-based seismic control system even when a large-scale earthquake with a recurrence period of 2400 years occurs. 4.5.3 Comparison and Analysis of the Load-Displacement Relationship and Displacement-Time Hysteresis  
Figure 20 presents the load-displacement curves of the test frame retrofitted with NBSD (PD-NBSD-WSCs) at 200, 300, and 400 cm/s\({}^{2}\), along with the load-displacement curves obtained from the test frame with no reinforcement applied (PD-FR) at 200 cm/s\({}^{2}\) for comparison. Figure 21 shows the seismic response displacement-time hysteresis curves of the test frame retrofitted with NBSD (PD-NBSD-WSCs) at 200, 300, and 400 cm/s\({}^{2}\), along with the curves obtained from the test frame with no reinforcement applied (PD-FR) at 200 cm/s\({}^{2}\) for comparison. Based on these results, both their seismic response strength ratios and displacement ratios, which are important parameters for seismic performance evaluation, were estimated and compared, as summarized in Table 10.