Multielement Hybrid Simulations for Performance Assessment of Multistory Special Concentrically Braced Frames

Accurate numerical modeling of structural components is necessary for both performance-based designs of new structures and performance assessments of existing structures. Steel special concentrically braced frames (SCBFs) represent a large portfolio of steel buildings in areas of high seismicity, especially in North America. Therefore, it is necessary to critically study the accuracy of available numerical models for SCBFs and propose improvements to them, if necessary. This requires forming a database of high-fidelity benchmark experimental results for SCBFs against which models can be compared. This paper presents multielement hybrid simulations on a steel SCBF, as a representation of systems with highly unsymmetrical hysteretic response. A representative buckling brace specimen is developed and verified through reversed-cyclic tests to physically capture the response of SCBFs in the experiments. 2-element and 4-element pseudo-dynamic hybrid simulations are carried out on the reference SCBF using the University of Toronto Ten-Element Hybrid Simulation Platform (UT10). The experimental results from the multielement tests are compared with numerical simulations in detail using the available numerical models, which are observed to predict the response well.