Study on the performance degradation of local pitting Q690 high-strength steel column

Abstract To study the mechanical properties of Q690 high-strength steel columns under the influence of localized pitting corrosion, numerical simulation tests were conducted on the bearing performance of Q690 high-strength steel columns with localized pitting. The effects of pit depth, width, and distribution on the degradation of their properties were investigated. The results indicated that as the depth and width of the pits increase, the ultimate bearing capacity of the Q690 high-strength steel columns decreases. Compared to the increase in pit width, increasing the depth of the pits results in a greater degree of reduction in the bearing capacity of the Q690 high-strength steel columns. The R B (reliability index) for random distribution on both sides is 0.801, while the R B for the middle is 0.793. It can be concluded that random distribution on both sides of the member causes a slightly more severe degradation of the ultimate bearing capacity than in the middle. The R B for random distribution of pits is 0.007 higher than that for regular distribution, with the latter having a slightly higher ultimate bearing capacity. The research findings can provide a basis for structural design and theoretical research of Q690 high-strength steel columns under the influence of localized pitting corrosion.