Mechanism study on the interaction effects of shaking table array-test structure

To study the interaction mechanism of shaking table-test structure in shaking table test, an analytical model of shaking table array-test structure was established. Based on the analytical model, the influence of structure damping, frequency, and shaking table output on the accuracy of shaking table test was analysed. The analysis showed that compared with the actual frequency and theoretical response of the test structure, the measured structure frequency is decreased by 6.3%, and the peak value of seismic response of test structure is amplified 1.96 times. The interaction leads to 32% reduction of the waveform reproduction performance of shaking table. At the structure frequency and its surrounding frequency bands, the amplitude–frequency characteristic of shaking table is amplified 5.26 times, and the phase lag is 122.38° in the phase–frequency characteristic of shaking table. Based on the above results, it was indicated that the method that taking the output of shaking table as the input of structure will cause significant accuracy reduction when the interaction cannot be ignored. Finally, suggestions were given to improve the accuracy of shaking table test.