Buckling Of Steel Columns Research Articles

Repair of corroded and buckled short steel columns using concrete-filled GFRP jackets

Many bridges and structures in the United States that are supported on steel columns or piles exhibit inadequate strength due to increasing load demand or aging due to corrosion, or both. The combination of increased load demand and reduction of capacity due to corrosion-induced section loss can lead to unexpected buckling of the piles. This paper investigates the effectiveness of a glass fiber reinforced polymer (GFRP)-based technique for rapid retrofit of buckled steel piles or columns. The system consists of a GFRP jacket, which is formed on-site and subsequently filled with an expansive concrete. Thirteen-buckled short steel columns with varying degrees of section loss were repaired and tested to failure under axial compression. The research results indicate that the repair system restored the capacity of the buckled columns to between 69% and 104% of the capacity of the undamaged control column. Further the repaired piles exhibited a hardening response in the non-linear range rather than the sudden loss of capacity and softening response that is characteristically associated with buckling of steel columns. The findings suggest that installation of concrete-filled GFRP jackets can be an effective technique to rapidly repair corroded and buckled short steel columns or piles.

Experimental research on the creep buckling of fire-resistant steel columns at elevated temperature

The thermal creep is one of the major factors causing the buckle of steel columns in the fire events. But, few related studies have been reported to evaluate the factors affecting the thermal creep of steel column experimentally or numerically. In this study a series of Fire-resistant steel columns with three different slenderness ratios under a sustained load are tested under a uniform temperature up to six hours in order to evaluate the creep upon three selected factors, temperature, applied load, and column slenderness. Based on experimental results, a proposed creep strain rate model is established as the function of a single parameter of the load ratio of temperature LR(T) to determine the buckling time of steel column due to creep. Furthermore it is found that the creep can be neglected when LR(T) is smaller than 0.77.

Study on the Buckling of Steel Columns with one Special-Shaped Section

One large-diameter and non-circular steel tube was adopted in Henan TV tower (China). This special cross-section consists of three flat plates welded to three arc plates one by one. This paper studies the critical local buckling behavior of steel plates by using the finite element analysis method. Initial geometric imperfections and residual stresses presented in steel plates, material yielding and strain hardening were taken into account in the nonlinear analysis. An experimental study was performed to verify the capacity ability of this special steel tube. Based on the results obtained from the nonlinear finite element analyses and experiments, a set of design recommendations are provided for ensuring the safety of this special tube in Henan TV tower.

Elastic-Plastic Dynamic Response and Buckling of Steel Columns under Strong Vertical Ground Motion

Elastic-Plastic Dynamic Response and Buckling of Steel Columns under Strong Vertical Ground Motion