Soft real-time hybrid simulation based on a space steel frame

Soft real-time hybrid simulation (S-RTHS) is a novel seismic test method for structures. It combines pure finite element simulation with laboratory physical component tests, and can lead to a more realistic simulation of real-time effects of seismic action on specimens. Based on the OpenFresco test communication platform and an MTS electro-hydraulic servo loading system, a systematical study on the technological application of S-RTHS is presented in this paper. A single-story, single-span space steel frame was taken as a prototype, a column was taken as an experimental substructure, and the remaining part of the structure was taken as a numerical substructure to be simulated in OpenSEES. S-RTHS with bidirectional loading was performed, and the boundary conditions of the experimental substructure were simulated and analyzed. The results from the pure numerical simulations and S-RTHS were compared along with the responses from these simulations. The command displacement and feedback displacement of the system were discussed to verify the accuracy and stability of the S-RTHS. Finally, a comparison with the slow substructure hybrid simulation test results shows that the S-RTHS can better simulate the dynamic response of the experimental substructure.