Rectangular hollow section (RHS) brace members are easily mill- fabricated and are connected to the steel frame through tailored reinforced gusset- connector-brace systems.    

• But the RHS braces suffer from reduced ductility, lower notch toughness, and lower compression strength because of residual stresses and stress concentrations in the section corners.  

Circular hollow section (CHS) members avoid this corner effect, but pose different connection challenges.  

A structural connector in building construction has to meet stringent building code requirements and should be easy to design for a range of structural forces and configurations, have low production cost, and provide simple field fabrication.