For the seasoned seismic designer, Buckling Restrained Braced Frames may be a familiar structural system, however, some structural engineers may not be quite as familiar with their use. These prefabricated, or manufactured brace elements consist of a steel core and a buckling-restraining system, and they exhibit robust cyclical performance and have large ductility capacity. Their use in seismic applications has become more popular, and can be an option to consider for some seismic retrofit designs.
In July 2017, Kimberley Robinson, PE, SE from SunSteel, LLC presented Buckling Restrained Braced Frames for SE University. Kim’s presentation covered design principles of Buckling Restrained Braces, as well as tips for coordinating with BRB manufactures to ensure the braces supplied match the design intent of the EOR. Kim provided guidelines on what is needed to properly specify Buckling Restrained Braces and referred to other published articles that include guidance on BRB design and specification.
As shown in the slide below, Kim provided an example of a BRB Schedule and Notes to be included on the EORs drawings which include all of the pertinent design values needed to coordinate with the BRB manufacturer. Click on the slide to print your own copy.
Coordination with the BRB manufacturer is essential when designing Buckling Restrained Braced Frames. The iterative nature of the design requires the EOR to be proactive in communicating the necessary design and stiffness values with the BRB manufacturer to ensure the final design is well coordinated and meets all code requirements.