Grant: Collaborative Research and Development Grants

In a low-rise steel structure, the lateral support of the building is normally provided by vertical bracing system. During an earthquake, the brace helps dissipate the energy through inelastic deformation. When cycling through tension and compression, plastic hinges can form in the brace and the connection. The formation of these hinges leads to strain localization that accelerates the failure of the bracing system. Instead of using stocky braces designed to avoid kinking and connection fracture, very flexible braces that buckle elastically can be used to delay the formation of plastic hinge and improve the ductility of the bracing system. A very flexible brace can be constructed with a steel strap that has a large slenderness ratio. So far, no thorough study has been carried out to explore the usage of a steel strap as a very flexible brace. This research project will investigate the performance of various brace/connection configurations of steel strap braces experimentally and numerically under cyclic loading. Guidelines on the steel strap brace/connection design for low-rise steel framed buildings will be recommended. Results of this research may lead to large pre- and post-earthquake cost savings in low-rise steel framed buildings by using flexible steel straps as braces.