Built-in acoustic emission sensor mounting structure suitable for rock compression test

Abstract

A built-in acoustic emission sensor mounting structure suitable for a rock compression test comprises a loading pressing plate, an acoustic emission sensor probe, an isolation circular plate, an isolation washer, an isolation ring, a wave guide plate and a spring; wherein an acoustic emission sensor mounting hole with a two-stage stepped cylindrical blind hole structure is formed in the loading pressing plate, and the diameter of a cylindrical hole on the orifice side is larger than the diameter of a cylindrical hole on the hole bottom side, and the diameter of the cylindrical hole on the holebottom side is larger than the diameter of the acoustic emission sensor probe; the acoustic emission sensor probe is positioned in the cylindrical hole on the hole bottom side, the tail end of the acoustic emission sensor probe is in indirect abutting contact with the bottom of the cylindrical hole on the hole bottom side sequentially through the spring and the isolation circular plate, and the measuring end of the acoustic emission sensor probe is in indirect abutting contact with a rock sample through the wave guide plate; the wave guide plate is arranged in the cylindrical hole on the orifice side, and the isolation washer is arranged between the wave guide plate and a stepped surface of the mounting hole; the isolation ring is arranged between the wave guide plate and the cylindricalhole on the orifice side and is sleeved in an annular cavity body formed by an inner edge groove and an outer edge groove; the upper surface of the wave guide plate is provided with a probe limiting clamping groove; the loading pressing plate is internally provided with a lead threading hole, and a probe lead is led out of the loading pressing plate through the lead threading hole.

Description

technical field [0001] The invention belongs to the technical field of rock mechanics tests, in particular to a built-in acoustic emission sensor installation structure suitable for rock compression tests. Background technique [0002] When the rock sample is subjected to an external load, the strain energy stored in it will be released quickly and generate elastic waves, thereby emitting a sound, also known as acoustic emission. [0003] On the one hand, through the acoustic emission test of rock samples, not only the internal mechanism of rock damage and fracture can be revealed from the perspective of energy, but also the geological environment in which the rock is located can be predicted for in-situ stress; The monitoring of acoustic emission signals can predict geological disasters such as rockbursts in advance; therefore, rock acoustic emission tests play an important role in the field of rock mechanics tests. [0004] At present, in the rock compression tests at hom...

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Problems solved by technology

[0005] Taking the built-in installation structure of the acoustic emission sensor as an example, since the acoustic emission sensor is extremely sensitive to the sound signal, external noise can easily interfere with the acquisition of the acoustic emission signal of the rock itself. Therefore, how to effectively reduce the interference of external noise has become the installation structure of the acoustic emission sensor One of the difficulties and key points of the design; in addition, the acoustic emission sensor is generally a non-compressive vessel, and no external load is allowed to act directly during the test process. There is a difficulty in structural design; moreover, in order to collect accurate acoustic emission signals, in many existing designs, the acoustic emission sensor is directly in contact with the surface of the rock sample, and the tail end of the acoustic emission sensor is connected to the surface of the rock through a spring. Load the plate foundation, and this design will cause the rock sample to have no load near the installation hole of the acoustic emission sensor, which will lead to uneven stress on the surface of the sample, thus affecting the test results

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