Analysis and Behavior of Composite Transmission Towers

Composite transmission towers are hybrid systems that have been introduced to practice. Being composed of the most two used materials, structural steel and concrete, composite transmission towers present many advantages such as: economy, rigidity, fire resistant, durability, high stiffness due to the use of concrete; high strength, high ductility, easy to assemble, and fast to erect due to the use of steel. Recently, composite columns in transmission towers have been an alternative to steel transmission towers worldwide, especially in USA and Europe, yet little research has been performed in this field. Being composed of structural steel and non-homogenous concrete makes the bevahior of these structures challenging to understand. Therefore, this study presents the analysis and mechanical behavior of composite transmission towers. Three-dimensional non-linear finite element models were built using ABAQUS to compare and validate the behavior of the towers and materials against previous experimental work. The models include detailed analysis and investigation of the concrete and steel behavior up to failure using concrete damage plasticity (CDP) and bilinear elasto-plastic model respectively. Further extensive study was performed using different load cases to predict the behavior of bonds and load transfer between concrete and steel in composite transmission towers. Good comparison between the FE results and the experimental work has been achieved which lead to studying and investigating multiple forms of composite transmission towers.