Device and method for measuring radial deformation of tri-axial sample

Abstract

The invention discloses a device and a method for measuring radial deformation of a tri-axial sample, wherein the device is characterized in that a fixed bracket for a radial deformation measurement device comprises a locating bracket with the same central axis with a tri-axial pressure chamber; the locating bracket is tightly close to the tri-axial pressure chamber; the fixed bracket has a sliding block freely sliding without clearance along the single direction; the sliding block is linked with a displacement sensor and a laser ranger; vertical axes of the sliding block, the displacement sensor and the laser ranger are parallel to the axis of the bracket; non-contact and multi-directional measurement of a sample therein can be carried out outside the tri-axial pressure chamber; the device measures the surface distance of the sample by adopting the laser ranger; the sample is not interfered; the device is capable of measuring the sample in all directions outside the tri-axial pressure chamber; a radial deformation value of the diameter of the sample can be calculated through measured data by utilizing geometric knowledge; the error can be reduced through a multi-point measurement averaging method; and the practical deformation of the sample can be obtained according to light speed conversion.

Description

technical field [0001] The invention relates to a radial deformation measuring device and method for a triaxial sample, which is used for measuring the radial deformation of the sample in an indoor triaxial test. Background technique: [0002] According to the investigation, the methods used at home and abroad to measure the radial deformation of samples mainly include label reading, reading microscope measurement of scale spacing, local installation of strain gauges, PSD laser sensors, and laser sensors with fixed plane positions in pressure chambers. To deformation measurement. Most strain test methods will cause some interference to the sample, especially for samples with a softer texture, which will have a certain impact on their radial deformation. The methods of optical reading and strain measurement both measure the local deformation of the sample, and the measurement accuracy and reliability are relatively low. The light intensity has a great influence on the test o...

AI Technical Summary

Problems solved by technology

Most strain test methods will cause some interference to the sample, especially for samples with a soft texture, which will have a certain impact on their radial deformation

The methods of optical reading and strain measurement both measure the local deformation of the sample, and the measurement accuracy and reliability are relatively low. The light intensity has a great influence on the test of the PSD laser sensor, which brings certain errors to the test. The pressure chamber The measurement method of the fixed test device has poor portability and poor versatility on different instruments, and does not use small-diameter triaxial pressure chambers for measurement

The traditional measurement method has the disadvantages of disturbance to the sample, non-contact continuous measurement, low precision, poor flexibility, etc., so there are some obstacles in measuring the axial deformation of the triaxial sample

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