Development and Verification of Distributed Real-Time Hybrid Simulation Methods

Hybrid simulation combines numerical simulation and physical testing, and is thus considered to be an efficient alternative to traditional testing methodologies in the evaluation of global performance of large or complex structures. Real-time hybrid simulation (RTHS) is performed when it is important to fully capture rate-dependent behaviors in the physical substructure. Although the demand to test more complex systems grows, not every laboratory has the right combination of computational and equipment resources available to perform large-scale experiments. Distributed real-time hybrid simulation (dRTHS) facilitates testing that is to be conducted at multiple geographically distributed laboratories while utilizing the Internet to couple the substructures. One major challenge in dRTHS is to accommodate the unpredictable communication time delays between the various distributed sites that occur as a result of Internet congestion. Herein, a dRTHS framework is proposed where a modified Smith predictor is adopted to accommodate such communication delays. To examine and demonstrate the sensitivity of the proposed framework to communication delays and to modeling errors, parametric analytical case studies are presented. Additionally, the effectiveness of this dRTHS framework is verified through successful execution of multisite experiments. The results demonstrate that this framework provides a new option for researchers to evaluate the global response of structural systems in a distributed real-time environment. (C) 2017 American Society of Civil Engineers.