Abstract:
Hybrid simulation integrates numerical and experimental techniques to analyze
structural responses under static and dynamic loads. It physically tests components that are
not fully characterized while modeling the rest of the structure numerically. Over the past
two decades, hybrid testing platforms have become increasingly modular and versatile.
This paper presents the development of a robust hybrid testing software framework at the
National Laboratory for Civil Engineering (LNEC), Portugal, and evaluates the efficiency of
its algorithms. The framework features a LabVIEW-based control and interface application
that exchanges data with OpenSees via the OpenFresco middleware using a TCP/IP
protocol. Designed for slow to real-time hybrid testing, it employs a predictor–corrector
algorithm for motion control, enhanced by an adaptive time series (ATS)-based error
tracking and delay compensation algorithm. Its modular design facilitates the integration
of new simulation tools. The framework was first assessed through simulated hybrid tests,
followed by validation via a hybrid test on a two-bay, one-story steel moment-resisting
frame, where one exterior column was physically tested. The results emphasized the
importance of the accurate system identification of the physical substructure and the
precise calibration of the actuator control and delay compensation algorithms.
