Compressive behavior of innovative hollow long fabricated columns utilizing high strength and ultra-high strength tubes

摘要

Acomprehensive experimental study is carried out on the compressive behaviour of high strengthrninnovative hollow columns. In terms of geometric appearance, the innovative square section of columns is thernproduced by welding steel tubes with nominal diameter-to-thickness ratio of 23.78 to mild steel plates with arnnominal width-to-thickness ratio of 70. The tubes are of three types of mild, high strength (HS) and ultra-highrnstrength (UHS) steel with nominal tensile strength of 890MPa and 1380MPa, respectively. The connectionrnof high strength tubes to the sides of plates causes a satisfactory increase in the ductility and improves localrnbuckling behaviour of each mild steel plate whilst the restraint provided by plates enhances the resistance of eachrntube against global buckling. This effective interaction between the elements leads to taking advantage of thernhigh strength of tubes and, simultaneously, keeping the weight of the section as low as possible. Experimentalrnoutcomes of steel columns containing tubes are compared with similar columns without tubes, showing arnsignificant increase in the peak compressive load and ductility.