Structural performance of steel tubular X-joints with uniform pitting under axial compression

Tubular X-joints are commonly used in harsh environment that make them prone to pitting corrosion. This necessitates the evaluation of their load-bearing performance after corrosion. This study examines the influence of pitting corrosion on the structural performance of CHS X-joints, and the effects of pit size and shape on the weakening degree of bearing capacity were analyzed. Compression tests were conducted on four tubular X-joints with mechanically drilled pits of different depths. The results show that the ultimate strength and initial stiffness of test specimens reduced with pit depth, with maximum reductions reaching 49.20 % and 36.15 %, respectively. Finite element parameter analysis model verified by experiments considers the influence of pit size and shape on bearing capacity. The results indicate that the influence of pit diameter is greater than that of depth. When the pit spacing is in the range of 15 mm–20 mm, the ultimate strength and initial stiffness of the X-joint are less affected by the variation of pit spacing. The spherical pit is the most detrimental to the compressive capacity of the X-joint, followed by the cylindrical pit under the same corrosion level.