## 3 Test Results and Discussion
### Energy Dissipation Capacity  
The energy dissipation capacity in each cycle is evaluated by the equivalent viscous damping coefficient \(h_{e}\), which can be calculated using Equation (1). Figure 12 explains the definition of the equivalent viscous damping coefficient. Figure 13 exhibits the equivalent viscous damping coefficient of HPLW specimens. It can be concluded that the energy dissipating capacity increases as the web confinement increases. The equivalent viscous damping coefficient under the failure stage was 0.15, 0.18, 0.20, 0.21, 0.14, and 0.18 for the specimens HPLW500-1, HPLW500-2, HPLW650-1, HPLW650-2, HPLW800-1, and HPLW800-2, respectively. The equivalent viscous damping coefficient under the failure stage was 0.16, 0.18, 0.23, 0.21, 0.21, and 0.12 for the specimens LW500-1, LW500-2, LW650-1, LW650-2, LW800-1, and LW800-2, respectively. Therefore, it can be concluded that the HPLW and LW specimens all have good energy dissipation capacity by using the high-strength stirrup.  
\[h_{e}=\frac{1}{2\pi}\bullet\frac{S_{(ABC+CDA)}}{S_{\Delta OBE}+S_{\Delta ODF}} \tag{1}\]  
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline
**Specimen** & **Loading** & **\(\Delta_{y}\)** & **\(F_{y}\)** & **\(\Delta_{m}\)** & **\(F_{m}\)** & **\(\Delta_{u}\)** & **\(F_{u}\)** & & \\
**Direction** & **(mm)** & **(KN)** & **(mm)** & **(KN)** & **(mm)** & **(KN)** & **(KN)** & **\(\mu\)** & **\(\theta_{u}\)** \\ \hline HPLW500-1 & \(+\) & 12.1 & 107.1 & 43.5 & 181.2 & 46.2 & 154.5 & 3.8 & 1/30.3 \\ HPLW500-1 & \(-\) & 14.2 & 148.1 & 34.0 & 229.1 & 42.0 & 170.8 & 3.0 & 1/33.3 \\ HPLW500-2 & \(+\) & 9.9 & 168.8 & 33.8 & 300.1 & 38.1 & 241.1 & 3.9 & 1/36.8 \\ HPLW500-2 & \(-\) & 12.0 & 188.6 & 32.1 & 279.0 & 34.3 & 265.1 & 2.9 & 1/40.8 \\ HPLW650-1 & \(+\) & 10.0 & 245.3 & 27.6 & 414.8 & 30.0 & 351.0 & 3.0 & 1/46.7 \\ HPLW650-1 & \(-\) & 11.9 & 287.3 & 24.0 & 416.8 & 28.1 & 353.6 & 2.4 & 1/49.8 \\ HPLW650-2 & \(+\) & 12.0 & 264.4 & 35.9 & 522.6 & 38.0 & 396.9 & 3.2 & 1/36.8 \\  & \(-\) & 14.0 & 267.1 & 31.3 & 440.5 & 35.8 & 394.5 & 2.6 & 1/39.1 \\ HPLW800-1 & \(+\) & 12.0 & 228.9 & 37.9 & 385.2 & 41.7 & 327.0 & 3.5 & 1/33.6 \\ HPLW800-1 & \(-\) & 16.0 & 373.1 & 37.6 & 561.7 & 42.6 & 453.3 & 2.7 & 1/32.9 \\  & \(+\) & 12.0 & 256.2 & 33.8 & 427.9 & 36.0 & 394.1 & 3.0 & 1/38.9 \\ HPLW800-2 & \(-\) & 12.0 & 268.2 & 31.8 & 626.2 & 33.5 & 449.6 & 2.8 & 1/41.8 \\  & \(+\) & 7.3 & 113.6 & 19.8 & 148.5 & 42.5 & 131.8 & 5.8 & 1/32.9 \\ LW500-1 & \(-\) & 6.6 & 105.7 & 21.7 & 138.7 & 30.1 & 122.7 & 4.6 & 1/46.5 \\ LW500-2 & \(+\) & 4.9 & 101.8 & 20.5 & 152.2 & 25.0 & 144.6 & 5.1 & 1/56.0 \\  & \(-\) & 3.8 & 121.4 & 10.3 & 178.3 & 14.1 & 158.7 & 3.7 & 1/99.3 \\  & \(+\) & 7.1 & 160.5 & 22.3 & 194.5 & 28.1 & 184.2 & 4.0 & 1/49.8 \\ LW650-1 & \(-\) & 7.2 & 180.5 & 20.3 & 231.1 & 20.1 & 231.1 & 2.8 & 1/69.7 \\  & \(+\) & 5.1 & 100.0 & 22.0 & 153.2 & 29.9 & 150.2 & 5.9 & 1/46.8 \\ LW650-2 & \(-\) & 5.7 & 123.1 & 17.3 & 169.8 & 23.8 & 148.2 & 4.2 & 1/58.8 \\  & \(+\) & 7.6 & 220.9 & 12.9 & 258.1 & 14.5 & 228.8 & 1.9 & 1/96.6 \\ LW800-1 & \(-\) & 6.8 & 227.6 & 8.9 & 251.3 & 12.6 & 215.5 & 1.9 & 1/111.1 \\ LW800-2 & \(+\) & 5.8 & 160.0 & 12.7 & 192.2 & 16.2 & 172.1 & 2.8