НАДЕЖНОСТЬ И ДОЛГОВЕЧНОСТЬ ТРУБЧАТЫХ ЭЛЕМЕНТОВ СТАЛЬНЫХ КОНСТРУКЦИЙ ПРИ НЕРАВНОМЕРНЫХ КОРРОЗИОННЫХ ПОВРЕЖДЕНИЯХ

Abstract

Modern approaches and requirements for the design and expert assessment of the buildings and structures state require the quantitative determination of their reliability indicators. This determines the relevance of the development of methods for calculating the reliability of building systems, taking into account their properties and operating conditions. Corrosion damage to elements of metal structures can lead to loss of their functionality over time. The purpose of the research presented in the article is to identify and quantitatively describe changes over time in the reliability characteristics, according to the strength criterion, of an initially centrally tensile steel rod structural element of an annular section, taking into account uneven corrosive wear, which causes the occurrence of complex resistance of the rod, namely tension with bending. A calculation apparatus and an algorithm for determining the reliability and durability of an element were constructed using methods of reliability theory and the proposed spatio-time corrosion model. Calculations of these characteristics were carried out by varying the stochastic properties of the parameters of the rod’s cross section geometry, its stress state and the corrosion model at various degrees of corrosion factor aggressiveness. The loading of the rod was modeled by a stationary random function. The results of calculations of reliability, failure probability, corrosion coefficient and time density of failure probability are presented in graphs of the dependences of these values on time. The influence of the main design characteristics of the rod and the corrosion damage model on the reliability and durability of the structural element was assessed. The effect of a significant increase in the probability of failure and a decrease in durability with corrosion wear, uneven along the contour of the section, was revealed, in comparison with the case of a constant thickness of the corrosion layer, with comparable values of corrosion coefficients. The methodology and calculation results presented in the article can be used to obtain solutions to similar problems in other formulations (by cross-sectional shape, corrosion model, under non-stationary loading conditions, etc.), as well as to perform engineering reliability calculations when designing metal structures.