Composite Transmission Towers: Analysis, Behavior, Slip Investigation, and Interaction Diagrams

Composite transmission towers are hybrid systems that have been introduced to practice. Being composed of steel and concrete, composite transmission towers present many advantages such as: economy, rigidity, fire resistance, durability, high stiffness, high strength, high ductility, and easy to assemble and erect. Recently, composite transmission towers have been replacing the timber and steel transmission towers worldwide, yet few research studies have been performed in this field. Being composed of steel and concrete makes these structures' behavior challenging to predict. Therefore, this study presents the analysis and behavior of composite transmission towers. Three-dimensional non-linear finite element models were created using ABAQUS to compare and validate the behavior of the towers and materials against experimental work. The models include detailed analysis and investigation up to failure using concrete damage plasticity and bilinear elasto-plastic models. Good comparison between the FE results and the experimental work has been achieved which allowed to studying and investigating multiple forms of composite transmission towers. The analysis is expanded to study the slip between concrete and steel by comparing non-composite and composite assemblies using various number of stud arrangements. The analysis is expanded to obtain interaction diagrams for various diameter/width to thickness ratios beyond known code limits and practices.