Real-time hybrid test of a LNG storage tank with a variable curvature friction pendulum system

To accurately reproduce the seismic response of the liquefied natural gas (LNG) storage tank equipped with the variable curvature friction pendulum system (VCFPS), a real-time hybrid (RTH) experiment, also known as a real-time substructure experiment, is conducted on it in this study. A typical LNG storage tank with a capacity of 160,000 m(3) is employed as the numerical substructure simulated using the MATLAB/Simulink, while the variable curvature friction pendulum bearing (VCFPB) is utilized as the experimental substructure tested using the compression-shear equipment. Thereafter, the validity and feasibility of the RTH experiment are verified using the SAP2000 results. Finally, the working performance of the VCFPB is evaluated scientifically, comprehensively, reasonably, and efficiently. The results show that the VCFPB is very effective in avoiding the resonance phenomenon. It can be seen from the displacement of isolation layer that the VCFPB meets the design requirement. The maximum relative deviations between the RTH test results and the SAP2000 results are 3.45% for the displacement of isolation layer, 4.27% for the base shear, and 1.49% for the liquid sloshing height, respectively. The RTH test is stable and reliable and the predicted results are highly accurate and effective. The RTH test method proves to be accurate in the prediction of the seismic response of the LNG storage tank equipped with the VCFPBs.