Evaluation of frequency evaluation index based compensation for benchmark study in real-time hybrid simulation

Struct Control Health Monit

et al. 2020

Self Cite

Delay compensation method plays an important role in maintaining the stability and accuracy of the real-time hybrid simulation (RTHS). Inverse compensation (IC) method establishes a first-order discrete transfer function model to represent servo-hydraulic dynamics and provides an easy-to-implement compensation for RTHS. Only one parameter is required for the IC method, and it can be adjusted through different adaptive laws to accommodate error in initial delay estimation or time-varying delay throughout the test. Different techniques have been developed to improve the performance of the IC method such as dual compensation and adaptive IC (AIC). A windowed frequency domain evaluation index-based (WFEI) compensation is experimentally verified in this study through predefined tests and RTHS of a single-degree of freedom (SDOF) system. The frequency domain evaluation index (FEI) is applied through short-time Fourier transform (STFT) to estimate actuator delay in a real-time manner and to adapt the parameter of IC method to minimize possible delay variation and/or inaccurate estimation. The efficacy and robustness of the FEI-based compensation is further compared with the AIC method for various initial estimates, different window lengths, and bounds of estimated delay. Experimental results demonstrated that the WFEI method provides an effective and easy-to-implement method for RTHS.

Section: Formulation Of Wfei Compensation Methodsmentioning

confidence: 99%

Δ α_{i + 1} = ({, \begin{matrix} Δ α_{i} + d^{'} \cdot f_{s} & i = italicnL + 1, n = 1, 2, 3 \dots \\ Δ α_{i} & t \neq italicnL + 1_{s}, n = 1, 2, 3 \dots \end{matrix}),

Section: Formulation Of Wfei Compensation Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Experimental verification of a frequency domain evaluation index‐based compensation for real‐time hybrid simulation

Guo

Struct Control Health Monit

et al. 2020

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Experimental evaluation of CV‐Voronoi based adaptive sampling for Kriging meta‐modeling of multiple responses through real‐time hybrid simulation

Earthq Engng Struct Dyn

Hou

et al. 2022

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Real-time hybrid simulation (RTHS) integrates numerical modeling of analytical substructures with physical testing of experimental sub-structures thus enabling system global responses to be efficiently evaluated through component testing in size-limited laboratories. Traditional practice of RTHS focuses on responses evaluation of structures without considering their uncertainties. A cross-validation (CV)-Voronoi based adaptive sampling strategy is explored in this study for global meta-modeling of multiple response quantities of interests through RTHS for engineering systems with uncertainties. Based on the Kriging meta-model from initial samples, the CV-Voronoi based adaptive sampling sequentially identifies the sample points for RTHS tests in laboratory and observed responses of interests are used to update the Kriging meta-model. Multiple response distributions under structural uncertainties are thus acquired through limited number of experiments. RTHS tests of a two-degree-of-freedom system with selfcentering viscous dampers (SC-VDs) are conducted in this study to experimentally evaluate the effectiveness of the CV-Voronoi based adaptive sampling for multiple response estimation. The accuracy of multi-response meta-models are further evaluated through comparison with validation tests. A stopping criterion is finally proposed for more efficient implementation of the adaptive sampling strategy. It is demonstrated that the CV-Voronoi based adaptive sampling strategy provides a viable technique to enable accurate global meta-modeling and estimation for multiple responses with limited number of RTHS tests in laboratory.

Real‐time hybrid simulation with multi‐fidelity Co‐Kriging for global response prediction under structural uncertainties

Earthq Engng Struct Dyn

Yang

Hou

et al. 2022

Self Cite

Real‐time hybrid simulation (RTHS) provides an effective and efficient experimental technique to enable large‐ or full‐scale experiments to account for rate‐dependent behavior in size limited laboratories. Traditional practice of RTHS assumes deterministic substructure properties therefore could not account for structural uncertainties in global response prediction. This study explores the use of Co‐Kriging metamodeling for global response prediction under the presence of structural uncertainties. RTHS in laboratory is used as high‐fidelity (HF) modeling while computational simulation of the prototype structure under investigation is used as low‐fidelity (LF) modeling. Multifidelity modeling is integrated through Co‐Kriging to render accurate response prediction over the entire sample space of structural uncertainties. An entropy‐based adaptive strategy is used to sequentially determine the sampling points for HF RTHS and LF simulation. The proposed multifidelity Co‐Kriging approach is experimentally evaluated through RTHS of a single‐degree‐of‐freedom structure with a self‐centering viscous damper. The Co‐Kriging predicted maximum structural responses are further compared with validation tests. It is demonstrated that the Co‐Kriging can effectively reduce the number of RTHS tests in laboratory and significantly improve the metamodel accuracy for global prediction of structural response under uncertainties. The presented study presents an innovative way to further expand the capacity of RTHS for uncertainty quantification toward seismic hazard mitigation.