Structural Dynamic and Buckling Behaviour of Steel Cold‐formed Polygonal Conic Pole for Antennas Support

Abstract Support for antennas placed as high as 40‐50m demands traditional trussed steel or pole towers, the former with much larger base area than the later and the consequences for the costs of the ground occupancy. This aspect is of upmost importance for both urban and rural areas and the reason for the development of higher steel poles with polygonal cross‐section, searching for slender thin‐walled structures. The present research focus is cold‐formed steel conic twenty‐sided polygon solution allowing 40‐50m high antenna support, for which one must deal with the following challenges: (i) wind‐induced dynamic behavior, (ii) buckling analysis, (iii) localized stress concentration close to the openings along the pole, (iv) connection solution that strongly affects the erection procedure and (v) the fatigue effect. Beyond these aspects, results of the dynamic behavior, elastic buckling, nonlinear structural behavior until the collapse and design procedures for the computation of the structural strength of the steel pole are presented and commented, revealing the importance of structural analysis by combining tailored numerical tools as the finite strip and the finite element methods, as well as frequency domain methods for smooth and turbulent wind actions. Additional CFD and experimental wind tunnel results should be considered for advanced structural design, as well as experimental structural analysis to confirm the set of numerical results and the design procedures adopted for the steel polygonal poles.