Circumferential strain gauge for inner wall of circular hole

Abstract

Disclosed in the invention is a circumferential strain gauge for an inner wall of a circular hole. The circumferential strain gauge comprises a rigid ring; and an opening is formed in the rigid ring. A first support and a second support that are arranged in parallel are arranged in the rigid ring; and one end of each of the first support and the second support is fixed at the opening. In addition, the circumferential strain gauge also includes a first steel plate and a strain sensor; the strain sensor consists of a second steel plate and a resistor plate; a groove is formed in the second steel plate and the resistor plate is attached to the bottom of the groove; and a cable connected with the resistor plate is led out from a circular hole. One end of the first steel plate is fixedly connected with the other end of the first support; and the other end of the first steel plate is provided with a screw penetrating the first steel plate. The end of the screw is abutted against one end of the second steel plate; and the other end of the second steel plate is fixed at the other end of the second support. The first steel plate and the second steel plate are arranged horizontally. The provided circumferential strain gauge has advantages of reasonable design, simple structure, and high sensitivity and stability and is suitable for strain measurement of an inner hole.

Description

technical field [0001] The invention relates to rock deformation measurement, in particular to a circumferential strain gauge on the inner wall of a circular hole. Background technique [0002] As the complexity of engineering construction continues to increase, in order to better understand the mechanical properties of the rock mass on site, it is necessary to conduct laboratory mechanical tests on the rock to obtain the strength, deformation and failure form of the rock under complex stress. Avoid major engineering accidents caused by rock deformation and damage. [0003] During the site excavation of engineering rock mass, the stress state inside the rock mass is extremely complex, which is manifested as: the change of the principal stress when the direction of the principal axis of stress remains unchanged, the rotation of the principal axis of stress when the magnitude of the principal stress remains unchanged, the rotation of the direction of the principal axis of stre...

AI Technical Summary

Problems solved by technology

For the rock hollow cylinder torsional shear instrument, strain gauges are mainly used to measure the strain gauge on the surface of the rock sample. This method has the following disadvantages: 1) During the process of processing the rock sample, the inner wall of the inner hole is not smooth, and there are drill holes. 2) The size of the rock sample used for the test is small, and the working space for pasting the strain gauge in the inner hole of the rock sample is small, so it is difficult to control the strain gauge. 3) The strain gauge is very fragile and is easily damaged in the later rock sample preparation process, and once damaged, the data acquisition at this position can only be abandoned, resulting in the obtained data being inaccurate. Complete; 4) The data measured by the strain gauge can only reflect the local deformation of the paste area, which has limitations

[0005] The accuracy and reliability of the strain gauge method are not high, and the operation is cumbersome, which limits the collection of test data and affects the analysis of test results

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