Abstract
Metal transmission line towers are critical components of power grid infrastructure and are subject to long-term exposure to environmental, mechanical, and operational influences that gradually reduce their structural performance. The relevance of this study is обусловлена the aging of a significant portion of existing transmission networks and the growing need to ensure their reliability and safety under prolonged service conditions. The objective of the article is to provide a comprehensive review and systematization of the main factors that reduce the service life of metal transmission line towers and to assess their combined effect on load-bearing capacity and durability. The study is based on analytical methods of strength of materials, fatigue theory, and corrosion modeling, as well as on the synthesis and comparative analysis of data from scientific and normative sources. The key results demonstrate that atmospheric corrosion, cyclic and dynamic loading, stress concentration in joints, and manufacturing and installation defects act jointly and significantly accelerate structural degradation. It is shown that even moderate corrosion rates and relatively low stress amplitudes can, over long periods, lead to substantial stiffness loss, accelerated fatigue damage accumulation, and an increased risk of failure. The scientific novelty of the work lies in the integrated consideration of these factors as an interconnected system rather than as isolated mechanisms, allowing a more realistic assessment of degradation processes. The practical significance of the results is associated with their applicability to residual life assessment, material selection, and the development of inspection, monitoring, and maintenance strategies for metal transmission line towers operating in continental climatic conditions.