Minitype piezoelectric telescopic element, compression wave measurement device and compression wave measurement method for centrifuge testing

Abstract

The invention discloses a minitype piezoelectric telescopic element, a compression wave measurement device and a compression wave measurement method for centrifuge testing. The minitype piezoelectric telescopic element comprises a tubular substrate and a processed piezoelectric ceramic piece, wherein the positive lead and the negative lead of a signal shielding wire are connected with the surfaces of two sides of the piezoelectric ceramic piece respectively, an inner epoxy resin layer, a conductive copper tape and an outer epoxy resin layer cover the surface of each of two sides of the piezoelectric ceramic piece, the grounding line of the signal shielding wire is connected with the conductive copper tape, and the piezoelectric ceramic piece is fixed on one end surface of the tubular substrate. The compression wave measurement device comprises a pair of minitype piezoelectric telescopic elements, a signal generator, a power amplifier, a principal axis slip ring of the centrifuge, a charge amplifier, an oscilloscope and the minitype piezoelectric telescopic element. According to the invention, good electromagnetic shielding effect is achieved, electromagnetic interference in the centrifuge is eliminated, the excited compression wave has strong bundling directivity, a reliable signal can be obtained in a strong interference environment, and the telescopic element has high compression wave excitation efficiency, and can be used in a high attenuation nearly-saturated water body.

Description

technical field [0001] The invention belongs to a soil compression wave test device, in particular to a miniature piezoelectric expansion element for a centrifuge test, a compression wave measurement device and a method. Background technique [0002] Compression wave is a kind of material body wave. According to the theory of elasticity, the elastic modulus of material and its compression wave velocity have the following relationship: E=ρV p 2 . Therefore, the stiffness parameters of the soil can be obtained through the elastic wave velocity test without disturbing the structure of the soil. For in-situ compression wave velocity testing, existing methods include downhole method, cross-hole method, etc., which are relatively mature in geotechnical engineering, and the reliability of the results is high. However, the indoor test soil sample size is small, the wave propagation time is short, the signal attenuation is fast, and the difficulty of signal discrimination is signi...

AI Technical Summary

Problems solved by technology

In short, in the centrifuge test, the measurement of the compression wave velocity of the model soil sample has not been effectively realized, and there are still many technical problems in its application.

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