Abstract
This paper presents a detailed re-examination of the coupled local and overall buckling strength formula, which is based on the Q-factor method, of a thin-walled column. For delicate comparison with experimental results, the strength formula expressed as function of initial imperfections is developed. Using this formula which takes into account the difference of initial imperfections in each specimen, experimental ultimate strengths are predicted. The results lead to the conclusion that Q-factor method has good accuracy, indicating that the error of prediction is less than 10%.
