## 5 Conclusions  
In this study, we addressed the problems of incomplete and unsystematic research on the performance of wheel coupler formwork support components by performing experiments. Additionally, the bearing capacities and failure modes of horizontal bars, vertical poles, and related components of a wheel coupler formwork support were analysed. The stability bearing capacities of single- and double-layer vertical poles were tested and analysed, and the variation of the stability bearing capacities of vertical poles under different working conditions was determined. The main conclusions were as follows:  
1. The eccentric tensile failure mode of the horizontal bar socket was buckling failure of the weld, and the bearing capacity was low. 2. The bending failure mode of the horizontal bar was the yield strength of the horizontal bar section, which was a ductile failure. No cracks formed in the weld seam at the connection between the socket and the horizontal bar, which verified the stability of the horizontal bar of the formwork support under normal working conditions. 3. According to the experimental analysis of the horizontal bar bearing capacity, the weld bearing capacity at the connection between the socket and the horizontal bar was the least among the three influencing factors. Therefore, the weak point of the bearing capacity of the horizontal bar of the formwork support was the weld seam at the connection between the socket and the horizontal bar. In practical engineering, the control of weld quality of the connection between the socket and the horizontal bar is key to ensure the bearing capacity of the horizontal bar and safe use of the formwork support. 4. Buckling failure of the weld at the connection between the wheel and the vertical pole occurred under shear force, and the shear capacity of the wheel decreased obviously with decreasing number of horizontal bars connected to the wheel. The sleeve shear failure mode was buckling failure, and the connection weld did not exhibit buckling failure in the bearing process, which basically corresponded to the normal use state. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Conditions**} & \multicolumn{3}{c}{**Experiment**} & \multicolumn{3}{c}{**FEA**} \\ \cline{2-7}  & \multirow{2}{*}{**Stability Bearing Capacity/kN**} & **Percentage** & **Stability Bearing** & **Percentage** & **Error** \\  & & **Capacity/kN** & **Decrease** & **Capacity/kN** & **Decrease** & \\ \hline \multirow{2}{*}{Single layer} & Central pole & 88 & 0\% & 92 & 0\% & 5\% \\  & Side pole & 82 & 7\% & 84 & 9\% & 2\% \\  & Corner pole & 73 & 11\% & 76 & 10\% & 4\% \\ \hline \multirow{2}{*}{Double layer} & Central pole & 76 & 0\% & 82 & 0\% & 5\% \\  & Side pole & 62 & 18\% & 66 & 20\% & 3\% \\  & Corner pole & 42 & 32\% & 50 & 24\% & 2\% \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Comparative analysis of the stability bearing capacity of the vertical pole. 5. The numerical model accurately predicted the buckling capacity of the wheel coupler formwork support over a large range. With a reduction in the number of horizontal bars connected to the vertical pole wheel disk, the stability bearing capacity showed a significant downward trend, especially with increasing layers; the stability bearing capacity decreased the most for the corner pole condition. The failure of a single-layer vertical pole was typical with lateral displacement buckling, while the double-layer vertical pole did not undergo buckling with lateral displacement. Conceptualization, Q.C. and J.D. ; Data curation, Q.C. ; Formal analysis, Q.C. ; Funding acquisition, H.L. ; Investigation, S.X. and L.T. ; Methodology, H.L. ; Project administration, M.L. ; Resources, H.L. ; Software, C.Y.L. and Y.F. ; Supervision, H.L. ; Validation, Q.C., H.L. and T.K.T.T. ; Visualization, J.D. ; Writing--original draft, Q.C. ; Writing--review & editing, S.X. All authors have read and agreed to the published version of the manuscript.