Performance of thin-walled box columns strengthened with internal braces

Thin-walled box members are susceptible to local buckling threat because the wall plates possess large width/thickness ratios. In order to improve the performance of the member, the deterioration of section integrity must be minimized. In this paper, the authors proposed a simple and effective method to enhance the member's performance by adding internal strengthening braces. Test results of 13 specimens show that the cyclic behavior, particularly energy dissipation, of steel thin-walled box columns with strengthening braces was significantly improved. It was also found that internal braces significantly reduced deterioration in strength after local buckling over bare steel-box section alone. The relationship between performance enhancement of members and stiffness of internal braces is also reported.