# Shear Strength of Trapezoidal Corrugated Steel Webs for Horizontally Curved Girder Bridges
## 4 Experimental Work
### Experimental Results
#### 4.3.2 Destructive Tests  
(1) Shear Buckling Stress of CSWs  
Based on the theoretical formulas (Section 2), the elastic global and local shear buckling stress of CSWs is shown in Table 14. It can be seen from Table 14 that the elastic global and local shear \begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline \multirow{3}{*}{**Specimens**} & \multirow{3}{*}{**Loading Case**} & \multirow{3}{*}{**Section**} & \multirow{3}{*}{**\(Q_{total}\)**} & \multicolumn{6}{c}{**Test Results**} & \multicolumn{6}{c}{**FEA Results**} \\  & & & & **(kN)** & & \(\gamma_{o}\) & \(\gamma_{i}\) & \(Q_{w}\) & \(Q_{total}\) & \(\gamma_{o}\) & \(\gamma_{i}\) & \(Q_{w}\) & \(Q_{w}\) \\  & & & & **(10\({}^{\circ}\))** & **(10\({}^{\circ}\))** & **(kN)** & \(Q_{w}\)/\(Q_{total}\)** & **(10\({}^{\circ}\))** & **(10\({}^{\circ}\))** & **(10\({}^{\circ}\))** & **(kN)** & \(Q_{w}\)/\(Q_{total}\)** \\ \hline \multirow{6}{*}{S3-t2d3} & Case 2 & A & \multirow{3}{*}{25} & 327 & 44 & 18.8 & 75.1\% & 344 & 34 & 19.2 & 76.6\% \\  & Case 2 & B & & 289 & 98 & 19.6 & 78.3\% & 267 & 111 & 19.1 & 76.6\% \\ \cline{1-1} \cline{2-10}  & Case 3 & A & \multirow{3}{*}{25} & 409 & \(-\)46 & 18.4 & 73.5\% & 442 & \(-\)62 & 19.2 & 76.8\% \\ \cline{1-1}  & Case 3 & B & & 366 & 14 & 19.2 & 76.9\% & 355 & 25 & 19.2 & 76.7\% \\ \cline{1-1} \cline{2-10}  & Case 4 & A & \multirow{3}{*}{25} & 233 & 128 & 18.3 & 73.1\% & 248 & 130 & 19.1 & 76.5\% \\ \cline{1-1}  & Case 4 & B & & 188 & 194 & 19.3 & 77.3\% & 181 & 197 & 19.1 & 76.4\% \\ \hline \hline \end{tabular}
\end{table} 
Table 13: Ratios of \(Q_{w}\) to the total shear force \(Q_{total}\) of specimen S3-t2d3. Figure 12: Shear strain distributions of CSWs for specimen S3-t2d3: (a) A section; (b) B section. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Specimens**} & \multirow{2}{*}{**Section**} & \multirow{2}{*}{**Loading Case**} & \multirow{2}{*}{**Vertical Position (mm)**} & \multicolumn{6}{c}{**\(F_{e}\) (kN)**} \\ \cline{6-8}  & & & & **10** & **20** & **30** & **40** & **50** \\ \hline \multirow{3}{*}{S2-t2d2} & \multirow{3}{*}{B} & \multirow{3}{*}{Case 1} & 300 & 41.73\({}^{\circ}\) & 40.99\({}^{\circ}\) & 41.29\({}^{\circ}\) & 41.59\({}^{\circ}\) & 41.68\({}^{\circ}\) \\  & & & 180 & 43.17\({}^{\circ}\) & 44.04\({}^{\circ}\) & 44.40\({}^{\circ}\) & 44.59\({}^{\circ}\) & 44.60\({}^{\circ}\) \\  & & & 60 buckling stresses of CSWs are larger than the shear yield stress of CSWs, that is to say, the occurrence of shear buckling occurs after the yielding of CSWs which meets the general safety criterion of bridge design [33]: yielding before local shear buckling, and local buckling before global shear buckling. In this way the full strength of the girder is mobilized. While local buckling cannot induce girder failure, global shear buckling can. After local buckling the load can still be increased. 2. Experimental Phenomena and Results In the destructive tests, a three-point loading was applied (see Figure 8 Case Y and Case 3). The final deformed shape of the test specimen S1-t1d2 at the end of testing is presented in Figure 13. The final buckling shapes are presented in Figures 14-16. From the experimental phenomena it is clear that local shear buckling occurred first in one of the corrugated panels. Then, with increasing load, the buckling propagated to adjacent panels. In the final state, the interactive shear buckling and the global shear buckling occurred in all specimens. It should be pointed out that the buckling of the CSWs occurred after the yielding of the CSWs which is in good agreement with the theoretical prediction. Figure 17 shows the load-deflection curves of test girders. the curves do not give the displacement state at the stage of critical load due to failure of the displacement meters. The loads at which local buckling occurred are 65.9 kN, 140 kN and 147 kN for S1-t1d2, S2-t2d2, and S3-t2d3 respectively. The critical loads are 94.3 kN, 190 kN, 157.9 kN respectively.