Steel silo design and optimization

Silos are defined as large, vertical structures designed for the storage of grain, feed, cement and other bulk materials used in agricultural and industrial areas. Silos are usually cylindrical in shape and provide long-term storage and protection of the materials they contain from external factors. They can be made of different materials such as steel, concrete or wood, and criteria such as cost, durability and lifetime are taken into account when choosing these materials. Steel silos are widely preferred due to their high strength and durability. The engineering design of silos utilizes disciplines such as materials science, structural analysis, thermodynamics and fluid mechanics. Silo design and optimization is a complex and multifaceted process involving many branches of engineering science. Careful consideration of factors such as structural durability, material selection and economic efficiency ensure that silos operate safely and efficiently. The primary objective of this study is to design a steel grain silo under optimal conditions and to conduct analyses of these designs. The methodology employed in this study initially involves examining the general features and design criteria of steel grain silos based on information available in the literature and industry standards. Following this examination, various silo models with different sheet thicknesses were created using SolidWorks 2024 software. For these models, suitable materials were selected, and safety factors were calculated. To enhance the stability of the silo and minimize potential structural issues, support elements were incorporated into the design. The structural material, which constitutes a large part of the cost of steel silos, was tried to be lightened without exceeding the recommended safety stress value. In this study, 85 silo models with different sheet thicknesses and support elements were created for grain storage. The dimensions of the silo were determined as 4.77 meters in diameter and 10.5 meters in height (excluding the roof) using 1500x3000 mm sheet metal without cutting and were kept constant throughout the research. St44 structural steel was chosen as the material due to its weldability, machinability and cost effectiveness. In the next phase, the structural analyses of the created silo models were performed using ANSYS finite element software. In the analyses conducted with ANSYS software, the total deformation, strain, and stress values under static loading conditions were calculated for each silo model. Additionally, the total weight of each design was evaluated. The data obtained from these analyses were compared to determine the optimal silo design that provides the best balance of performance and cost. As a result of this thesis study, the effects of sheet thickness, material selection, and support elements used in the design of steel grain silos were thoroughly examined and analyzed. Based on the analyses conducted, a safe and economical steel grain silo design was proposed, taking into account various design parameters. It was observed that instead of using only steel plates, the necessary safety values could be achieved by placing NPU and flat bar support elements made of the same material in appropriate regions, significantly reducing the overall weight of the silo body. It was concluded that, compared to a model using uniform sheet thickness to ensure safety, a design with variable sheet thickness and reinforced support elements could reduce the reference silo weight by 58%. This study serves as an important resource for the design and analysis of steel grain silos in the industry and provides valuable guidance for future similar studies.