Numerical Analysis of Cold-Formed Thin-Walled Steel Short Columns with Pitting Corrosion during Bridge Construction.

Pitting corrosion is harmful during bridge construction, which will lead to uneven roughness of steel surfaces and reduce the thickness of steel. Hence, the effect of pitting corrosion on the mechanical properties of cold-formed thin-walled steel stub columns is studied, and the empirical formulas are established through regression fitting to predict the ultimate load of web and flange under pitting corrosion. In detail, the failure modes and load-displacement curves of specimens with different locations, area ratios, and depths are obtained through a large number of non-linear finite element analysis. As for the specimens with pitting corrosion on the web, all the specimens are subject to local buckling failure, and the failure mode will not change with pitting corrosion, but the failure location will change with pitting corrosion location; the size, location, and area ratio of pitting corrosion have little influence on the ultimate load of cold-formed thin-walled steel short columns, but the loss rate of pitting corrosion section area has a greater impact on the ultimate bearing capacity. As for the specimen with flange pitting corrosion, the location and area ratio of pitting corrosion have less influence on the ultimate load of cold-formed thin-walled steel short columns, and the section area loss rate has greater influence on the ultimate bearing capacity; the impact of web pitting corrosion on the ultimate load is greater than that of flange pitting corrosion under the same condition of pitting corrosion section area. The prediction formulas of limit load which are suitable for pitting corrosion of web and flange are established, which can provide a reference for performance evaluation of corroded cold-formed thin-walled steel. [ABSTRACT FROM AUTHOR]