Design Wind Directions in Bearing Capacity Assessment of Triangular Antenna-Mast Structures

The influence of wind direction on the stress-strain state of triangular lattice antenna-mast structures with heights ranging from 40 to 72 meters is examined. The study focuses on five real-world steel towers of varying geometries, located in the Kaluga, Tula, and Ryazan Regions of the Russian Federation. Structural analysis was performed using the finite element method in the SCAD Office software environment. The investigation involved pairwise comparisons of internal forces in key structural elements (chords, diagonals, and horizontal braces) under two wind directions: the standard (perpendicular to the windward face of the tower) and along one of the faces, which is not considered in national design codes. It was found that wind acting along a tower face can, in several cases, induce internal forces that exceed those under the standard direction by 20-60%. Distinct patterns of force redistribution along the tower height and spatial torsional effects were also observed. The results demonstrate the necessity of expanding design scenarios for tower structures to include non-standard wind directions, which are currently overlooked in engineering practice. This study fills a research gap and contributes to the development of improved design methods and regulatory frameworks for lattice antenna-mast structures.