Comparison of Dynamic Analysis Methods in a Cable-Stayed Tower Under Extreme Wind Loads in Cuba

Abstract

Several methods and investigations have been conducted in order to dynamically analyze the behavior of guyed mast telecommunication towers subject to wind loading, due to the importance of such structures in current society. Due to their slenderness, flexibility and lightweight, these structures are particularly susceptible to wind loads, being strong hurricane winds the cause of several tower failures in Cuba. This works conducts the study of a 120 meters tall guyed mast, model MAR 2008, facing extreme wind loads in two different locations. The structure is modeled using the computational assisted software SAP2000 and a dynamic analysis is undertaken using two methods: the equivalent static method "Patch Load" and the full dynamic method "Time History" using Direct Integration. The basic wind speeds are determined according to the Method of Independent Storms (MIS) and standard turbulence intensities for cyclonés regions. Synthetic functions are generated for different heights of the tower in order to apply the "Time History" dynamic method. Finally, a comparison is established between the results in terms of axial loads, joint reactions and displacements. The main conclusion of the study is that as the basic speed decreases, there is a higher resemblance in inner forces and displacements between the results obtained for the two studied methods.