Analysis of the air rubber dam using “ANSYS”

Inflatable dams have been used as a storage system of water along seasonal and non-seasonal rivers for agriculture and the other uses from 50 years ago. Due to plasticity of the structure and continuous variation of its shape during operation, it’s structural and hydraulic analysis is more complicated than the other dams such as concrete or earth dams. As a result, design of the rubber dam is very complicated. This paper deals with analysis of the rubber dam using ANSYS. ANSYS is finite element based software capable of predicting behaviors of the rigid and flexible structures such as flexible rubber dams. In the present study, first, ANSYS is applied to an assumed rubber dam with some realistic characteristics. Then, it has been applied to the Babolsar rubber dam, Iran. This paper has modeled a cantilever air rubber dam under the air internal pressure and the water external pressure. It is found that increasing of internal pressure causes a circular section of the dam up to a specified pressure. After this pressure, the dam starts to deform around its fixed axis and finally it will be ruined. The rubber dam as a weir is very sensitive to the V-notch phenomenon on its crest. The V-notch is not stable and causes the continuous variation of the coefficient of discharge. It may be cause of instability of the structure. In this paperV-notch phenomenon and its effects on the dam hydraulics has been modeled by “ANSYS” as well. Finally, it is concluded that study and design of any rubber dam needs a mathematical modeling (or physical modeling) to find out its characteristics.