Numerical modeling of high-strength steel composite K-eccentrically braced frames and spatial substructure hybrid simulation tests

Substructure hybrid simulation test (SHST) is a novel seismic experimental method for analyzing structures, which usually divides the global structure into two components: the experimental substructure and the numerical substructure. An SHST system based on the OpenFresco platform was established. To ensure the high accuracy of the numerical substructure in SHST, a finite element model that corresponded to a quasi-static experimental investigation on high-strength steel composite K-shaped eccentrically braced frame (K-HSS-EBF) was established and analyzed using OpenSees. A three-story and five-span spatial K-HSS-EBF was used as the prototype and the three-story steel frame with a K-eccentric brace on the left second span was taken as the experimental substructure. The remaining four-span was modeled as a numerical substructure in OpenSees. SHST was performed with a half-scale hybrid simulation model. According to the test results, the displacement loading precision of the experimental substructure was analyzed. In addition, the shear link rotations of the experimental and numerical substructures were compared. The time curve of the displacement and the base shear of the hybrid simulation model were also compared with the simulation results of the global numerical model. The results revealed that the seismic response characteristics of the K-HSS-EBF were successfully recaptured using the numerical substructure model established in OpenSees and the spatial SHST system based on OpenFresco.