The empirical corner stiffness for right-angle frames of rectangular and H-type cross-sections

The consistent growth of industry and improvements in living standards has placed continuous new demands on the water supply. Many dams have been constructed to meet these demands. A key component of a dam is the gates used to control and adjust the water levels and flow rates. A slide gate is typically used as a small-sized gate. Although its operating resistance is large, it has a simple structure and is relatively inexpensive. The role of the bonnet has been highlighted in high pressure slide gates. Until now, the finite corner stiffness of the right frames used as horizontal girders in a bonnet have not been considered during the design process, meaning that the current design concept for the girders in slide gates is not precise. Accordingly, this paper presents design equation set I for the right frames used as horizontal girders in a bonnet, assuming rigid corner stiffness. By comparing the center stresses of the right frame using design equation set I with the result of FEM, the master curves for empirical corner stiffness could be determined as a function of slenderness ratio. The design equation set II for the right frame assuming finite corner stiffness was derived and compared with the former equations. Using the master curves for the corner stiffness and design equation set II, the precise design moments at the centers of the girder can be determined so the bending stresses can be analyzed more precisely. Therefore, when designing a right angle frame itself or right frames used as horizontal girders in the bonnet of a slide gate, the master curves for the corner stiffness can be used for a more precise analysis and design.