Compressive behavior of H-shaped brace strengthened with non-welded cold-formed element

• This study suggests reinforcement details to restrain the flexural buckling of slender H-shaped braces and enable them to resist compressive force.
• In order to evaluate the behavior of the suggested reinforcing member, preliminary test and full-scale monotonic compressive loading test were carried out.
• The parameters in the test were slenderness ratio and reinforcement area ratio.
• It was observed from the test that the suggested reinforcing member restrained the flexural buckling of slender brace and induced stable behavior of the brace when compressive force was applied.

As seismic design code was revised in Korea in 2009, the seismic performance of the structures which were not built in compliance with the code need to be reviewed. In middle and low-rise buildings, braces resist most of lateral force. Therefore, it is critical to decide how to reinforce the braces in middle and low-rise buildings to ensure structural safety when seismic load is applied repeatedly. This study suggests reinforcement details to restrain the flexural buckling of slender H-shaped braces and enable them to resist compressive force. In order to evaluate the behavior of the suggested reinforcing member, preliminary test and full-scale monotonic compressive loading test were carried out. The parameters in the test were slenderness ratio and reinforcement area ratio. It was observed from the test that the suggested reinforcing member restrained the flexural buckling of slender brace and induced stable behavior of the brace when compressive force was applied. According to the tests, the area of reinforcing member should be more than 1.7 times of that of core member and the length of the former should be at least 80% of that of the latter.