## 4 Experimental Results
### Earthquake Excitation Case
#### 4.4.1 Vibration-Suppression Effectiveness  
Given the extensive dataset (12 seismic records), displacement responses under four representative seismic waves are plotted in Figures 9-12, with peak response values and RMS vibration-reduction rates summarized in Table 3. The experimental data demonstrate that the SPPTMD effectively mitigates structural displacement responses under seismic loading, achieving peak and RMS vibration-reduction rates of 60.25% and 58.35%, respectively. The results further indicate that the vibration control efficiency will increase when the ground is softer. For instance, the average peak vibration-reduction rate of the three earthquakes in venue class I is 42.9%, whereas that of venue classes II, III, and IV are 44.06%, 45.15%, and 50.27%, respectively. Similarly, the average RMS vibration-reduction rate increased from 36.06% (class I) to 36.60% (class II), 44.45% (class III), and 56.78% (class IV), with all indicating that the vibration control performance of the SPPTMD increased with increasing venue class.  
\begin{table}
\begin{tabular}{c c c c c} \hline
**Class** & **ID** & **Earthquake** & **Event Date** & **Station** \\ \hline \multirow{3}{*}{I} & EQ1 (experiment + simulation) & Northridge & 1994 & Lake Hughes \\  & EQ2 (simulation) & Duzce Turkey & 1999 & Lamont \\  & EQ3 (simulation) & Chi-Chi & 1999 & ILA050 \\ \hline \multirow{3}{*}{II} & EQ4 (experiment + simulation) & Kern County, & 1952 & Taft \\  & EQ5 (simulation) & Morgan Hill & 1984 & Foster City \\  & EQ6 (simulation) & Landers & 1992 & Desert Hot Springs \\ \hline \multirow{3}{*}{III} & EQ7 (experiment + simulation) & Imperial Valley & 1940 & El Centro \\  & EQ8 (simulation) & Borrego & 1942 & El Centro \\  & EQ9 (simulation) & Coyote Lake & 1979 & Gilroy \\ \hline \multirow{3}{*}{IV} & EQ10 (experiment + simulation) & Loma Prieta & 1989 & APEEL 2 \\  & EQ11 (simulation) & Kobe & 1995 & Kobe University \\ \cline{1-1}  & EQ12 (simulation) & Iwate & 2008 & HKD161 \\ \hline \end{tabular}
\end{table}
Table 2: Seismic records.  
Figure 9: Response of the model under EQ1.  
Figure 11: Response of the model under EQ7.  
Figure 12: Response of the model under EQ10.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Class**} & \multirow{2}{*}{**ID**} & \multirow{2}{*}{\(\eta_{d}\) (\%)} & \multirow{2}{*}{\(\eta_{\text{RMS}}\) (\%)} & \multicolumn{2}{c}{**Average**} \\ \cline{5-6}  & & & & \(\eta_{d}\) (\%) & \(\eta_{\text{RMS}}\) \\ \hline \multirow{3}{*}{I} & EQ1 & 44.83 & 30.81 & \multirow{3}{*}{42.90} & \multirow{3}{*}{36.06} \\  & EQ2 & 36.92 & 49.80 & & \\  & EQ3 & 46.94 & 27.56 & & \\ \hline \multirow{3}{*}{II} & EQ4 & 38.66 & 42.22 & \multirow{3}{*}{44.06} & \multirow{3}{*}{36.60} \\  & EQ5 & 41.53 & 19.81 & & \\  & EQ6 & 52.00 & 47.78 & & \\ \hline \multirow{3}{*}{III} & EQ7 & 47.08 & 55.93 & \multirow{3}{*}{45.15} & \multirow{3}{*}{44.45} \\  & EQ8 & 43.20 & 24.71 & & \\ \cline{1-1}  & EQ9 & 45.18 & 52.70 & & \\ \hline \multirow{3}{*}{IV} & EQ10 & 38.60 & 55.19 & \multirow{3}{*}{50.27} & \multirow{3}{*}{56.78} \\  & EQ11 & 51.97 & 56.79 & & \\ \cline{1-1}  & EQ12 & 60.25 & 58.35 & & \\ \hline \hline \end{tabular}
\end{table}
Table 3: Vibration-reduction ratios of the model.  
Figure 10: Response of the model under EQ4.  
Figure 12: Response of the model under EQ10.