Charge-voltage converter for piezoelectric intelligent aggregate seismic damage monitoring system

Abstract

The invention provides a charge-voltage converter for a piezoelectric intelligent aggregate seismic damage monitoring system. The charge-voltage converter is formed by connecting a plurality of integrated circuit plates in parallel. Each integrated circuit plate comprises a signal source amplifying unit, a control unit, a gain display unit and a power supplying unit, wherein the signal source amplifying unit is formed by sequentially connecting a charge-voltage conversion circuit, a controllable gain amplifying circuit, a controllable filter circuit, a low-pass filter circuit, a high-pass filter circuit and a voltage ejection follower; the gain display unit comprises an electronic switch and a gain indicator light circuit; the control unit is respectively connected with an ejection follower output end, the controllable gain amplifying circuit, the controllable filter circuit, the electronic switch and a computer signal acquisition system, and is used for monitoring an output signal, controlling voltage gain and gain display and controlling the filter cutoff frequency; and the output voltage and the corresponding gain value are sent to a computer data acquisition system through an interface to display. The charge-voltage converter has the advantages of being capable of simultaneously acquiring multi-path of signals, reliably monitoring the concrete structure dynamic damage in seismic processes with different intensities; and the charge-voltage converter is simple in construction and stable in performance.

Description

technical field [0001] The invention relates to a multi-channel, large charge, and variable gain charge-voltage converter used in a piezoelectric intelligent aggregate earthquake damage monitoring system, especially capable of collecting charge data in the whole process of monitoring dynamic damage inside concrete. Background technique [0002] Monitoring the internal stress of concrete structures under earthquake is of great significance for understanding the structural damage mechanism, optimizing the seismic design of structures, and reducing the risk of structural earthquake damage. Piezoelectric intelligent aggregate uses concrete coarse aggregate material as the matrix to couple with PZT sheets, and uses the positive piezoelectric effect to monitor the structural dynamic stress. The monitoring effect largely depends on the conditioning of the monitoring signal by the secondary instrument. The charge generated on the PZT needs to be converted into a voltage signal by a ...

AI Technical Summary

Problems solved by technology

[0003] Due to the large amount of charge generated on the PZT sheet under earthquake action, if the existing commercial charge amplifier is used for charge-voltage conversion, it is prone to overload and cannot be monitored; for soft building structures, the vibration frequency is very low, usually less than 0.2Hz, the time constant of ordinary charge amplifiers is low, and it is impossible to accurately convert such low-frequency signals; under different intensity seismic inputs, the amount of charge generated on the PZT is different, and the charge amplifier for modulation should use the corresponding gain

Due to the uncertainty of the input strength and frequency of earthquake motion, ordinary charge amplifiers cannot automatically adjust the gain and cut-off frequency according to the input of earthquake motion, so they cannot meet the accuracy requirements of multi-scale measurement

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