Real-Time Error Monitoring for Hybrid Simulation. Part I: Methodology and Experimental Verification

The hybrid simulation test method is a versatile technique for evaluating the seismic performance of structures by seamlessly integrating both physical and numerical simulations of substructures into a single test model. Hybrid simulation results have been shown to be reliable by comparison to shake-table simulations when propagation of experimental errors is successfully mitigated. Techniques have been proposed to assess the severity of experimental errors prior to or after tests have been completed. In this paper, an error monitoring method is presented that predicts the reliability of the test results in real time using data that is readily available. Two error monitors are derived based on estimates of energy added to the hybrid simulation as a result of errors in the experimental setup. The proposed method can provide valuable decision-making information by generating early warnings of unacceptable levels of experimental errors. The warning signals can serve as an indicator to pause the simulation, examine the source of error, and correct the problem, preferably before the specimen is irreparably damaged. Use of the proposed hybrid simulation error monitors to provide a measure of confidence of the quality of the test results is verified in two hybrid simulations.