Plastic buckling of dented steel circular tubes under axial compression: An experimental study

• Dent׳s depth was the most important variable on the load capacity.
• The closer the dent to the one end the less the ultimate capacity.
• Axial stress flow lines deflected to the sides upon approaching the dent.
• SG.1 and SG.2 recorded negative values whereas SG.3 showed positive.
• The orientation of the dent seemed not to have a remarkable effect.

This paper examines the effect of large local imperfections, known as dents, on the plastic buckling capacity of short steel tubes under axial compression. A total of 11 tests on such short columns were carried out. The specimens were indented through a separate process and the ultimate axial capacity was subsequently obtained through compression tests. Dent imperfections with various depths were introduced to different locations on the body of the specimens. Plastic buckling modes as well as the ultimate capacity of the specimens were thoroughly investigated. The adverse effect of such a local damage on the load carrying capacity was quantified for different values and types of imperfections.