The following are two good links on how to design Buckling-Restrained Braced Frames (BRBFs):

ATC 121

• NEHRP Seismic Design Technical Brief No. 11:  Seismic Design of Steel Buckling-Restrained Brace Frames, A Guide for Practicing Engineer

• https://store.atcouncil.org/index.php?dispatch=products.view&product_id=289

Steel Tips

• Seismic Design of Buckling-Restrained Braced Frames

• http://www.steeltips.org/steeltips/tip_details.php?id=76