Design of Buckling-Restrained Braced Frames Using Nonlinear Time History Analysis and Optimization

Abstract

A procedure for the design of buckling-restrained braced frames is presented. The procedure uses nonlinear time history analysis and optimization. Results from this procedure are compared to those from the commonly used equivalent lateral force procedure. Results are used to develop design curves and formulas for rapid determination of cross-sectional areas for buckling-restrained braces in each story. One interesting result is that the optimum variation of area from story to story is nearly linear for most cases studied. This result is not predicted by the equivalent lateral force procedure, and can only be discovered through optimization and nonlinear time history analysis.