ASSESSMENT OF THE IMPACT OF OPERATING CONDITIONS ON THE RELIABILITY OF BAR-TYPE STEEL STRUCTURES

Purpose. The study aims to develop a comprehensive approach to calculating the residual service life of spatial multi-element steel bar structures, taking into account both predictable and random factors that affect the structures or their individual elements throughout their service life. Methodology. The key causes of corrosion damage are examined, and models of corrosion wear are analyzed, including those that consider the effects of mechanical stresses and aggressive environments. The use of different types of survivability indicators – both deterministic and stochastic – allows for a more accurate assessment of structural reliability under real operating conditions. It is noted that current construction standards insufficiently account for the time-dependent development of defects, which complicates the assessment of the residual service life of structures. The need for a comprehensive approach to forecasting the reliability and durability of steel structures in actual service conditions is emphasized. Findings. It is demonstrated that traditional calculation methods do not adequately assess the durability and survivability of structures with evolving defects. An approach to evaluating the survivability of steel structures is proposed, based on the use of both deterministic and stochastic indicators. This allows for consideration of both systematic and random changes in the behavior of the structural system. The advantage of mathematical modeling over physical modeling is substantiated, particularly in its ability to account for multiple scenarios of corrosion development and the complex interaction of corrosion with mechanical influences. Parameters characterizing the condition of a structure under corrosion wear have been identified. Originality. A comprehensive approach to assessing the reliability and survivability of bar-type steel structures under corrosion wear has been developed, based on a combination of deterministic and stochastic indicators. Mathematical models of corrosion damage are considered, taking into account the influence of both stress–strain state and aggressive environments. Practical value. The obtained results can be used in the design, diagnostics, and forecasting of the technical condition of bar-type steel structures operating in aggressive environments and exposed to various types of loads.