Seismic simulation shaking table control method used for compensating interaction between test piece and table top

Abstract

The invention relates to a seismic simulation shaking table control method used for compensating interaction between a test piece and a table top and improving the reproduction accuracy of seismic record. The control method is characterized in that control parameters of the shaking table are designed by taking all load forms as zero load forms based on the condition that the control parameters ofthe shaking table are designed by taking the test piece as rigid load; and the counter force generated by the test piece is utilized for compensating the interaction between the test piece and the table top in real time. Compared with a conventional control method, the method has the advantages of improving the stability of the system control to enable the seismic simulation shaking table to be more easily controlled; widening the system controllable frequency band to enable the test range of the shaking table to be wider; and improving the reproduction accuracy of the seismic record to enable the seismic simulation shaking table test to be more scientific.

Description

technical field [0001] The invention relates to an earthquake simulation vibration table control method for compensating the interaction between test pieces and table surfaces, and belongs to the technical field of anti-seismic tests of building structures. Background technique [0002] In the algorithm design of the shaking table control system for earthquake simulation, the platform and the specimen are usually treated as a single-degree-of-freedom system as a whole: figure 1 To form a structure for the earthquake simulation shaking table group, take the servo valve in the figure as the research object, the linear pressure-flow equation of the servo valve near the zero working point can be established, and the actuator cylinder as the research object, the actuator demand flow can be established Relationship,; taking the piston head as the research object, the actuator output force balance equation can be established. The above three relations are collectively referred to ...

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Problems solved by technology

Moreover, its participation ratio decreases with the decrease of its natural frequency. The load mass in the middle and high frequency bands rarely participates in the physical system of the shaking table. At this time, its characteristics are closer to no-load, while the frequencies required by conventional small and medium-sized shaking tables are all Above 50Hz, when using rigid load parameters, it is equivalent to using a large mass empty table parameter to control a small mass empty table. Therefore, when the mass of the specimen is large and the frequency is low, the shaking table system may be unstable, that is, the uncontrollable state ; In addition, the reaction force generated by the test piece will in turn affect the control performance of the shaking table. Due to the influence of resonance, the waveform of the frequency attachment of the test piece produces a greater reaction force, making the frequency of the test piece become the second resonance of the whole shaking table system Frequency has a great influence on the time-history tracking performance around the natural frequency of the structure, and the reproduction accuracy of the input wave component near this frequency is much lower than that of other frequency components; It is of great significance to improve the accuracy of seismic records reproduced by shaking table

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