Abstract:
In general tests, there is a big difference between the test piece and the table as the whole and the actual, which seriously affects the reproduction accuracy of the waveform.In response to this problem, the seismic simulation shaking table system and specimens were modeled according to the spring-damping model, and the influence of load quality, frequency, damping and other factors on the control performance of the earthquake simulation shaking table was analyzed.Simulation analysis shows that no matter the load quality, load frequency, and load damping, there are peaks at each frequency, and all are dominated by the first order influence. Compared with single-degree-of-freedom load, each frequency has a tendency to compensate each other, the load has a greater influence on the amplitude than it has on the phase.Aiming at the problem of greater influence of amplitude, a differential pressure feedback compensation algorithm is proposed to compensate for the interaction between the test piece and the table.The system's waveform reproduction accuracy before pressure difference compensation is 0.618 2, and after compensation it becomes 0.986 3, which greatly improves the waveform reproduction accuracy.