DESIGN AND TOPOLOGY OPTIMIZATION OF LOW HEAD RADIAL GATE FOR SPILLWAY USING ANSYS

Abstract

Almost every project of water resource has a diversion work or reservoir to store the water for power generation, irrigation, industrial and domestic water supply. A spillway with control mechanism is provided in almost every project to release the water during excess inflow. Radial gates are commonly used as control mechanism for spillways. Radial gates are hinged gates with the skinplate in form of circular arc with the centre of curvature at the trunnion or hinge. In this study a radial gate is designed for given technical parameters according to guidelines given in IS 4623. A 3D model of radial gate is developed on ANSYS using design modeler. This model is studied for different grade of structural steel and best grade is selected for further study. Topology optimization is performed on the model for best grade of structural steel. According to IS 4623 material for main component of radial gate is structural steel. In this study three grades of structural steel ASTM A 36, ASTM A 992 and ASTM A 588 are selected for study. Study shows that ASTM A 992 structural steel is the best material for radial gates as it gives minimum values of stresses for same loading and boundary conditions. Yield strength of ASTM A 992 structural steel is more as compare to ASTM A 36, hence ASTM A 992 is used for topology optimization. Topology optimization is performed using ANSYS to reduce weight and cost of radial gate. The weight of output model of topology optimization is 82% of the initial weight of model. This geometry is further modified using spaceclaim to perform design validation. This modification in geometry increases its weight to 85.85% of initial weight. Design validation is performed on modified geometry using ANSYS. Finally 14.15% reduction in weight is achieved and design validation shoes that stresses are within permissible limits.