Non-contact strain field and acoustic emission combined split type measuring system and method

Abstract

The invention discloses a non-contact strain field and acoustic emission combined split type measuring system and method. The system comprises a testing sample, two testing machine clamps, an acoustic emission sensor, an acoustic emission acquisition system, a camera, image acquisition control equipment and a fixing device, wherein the testing sample adopts a rectangular strip nonmagnetic material; the two testing machine clamps respectively clamp the upper and lower ends of the testing sample and stretch the testing sample; the acoustic emission sensor and the camera are respectively fixed on the left and right opposite sides of the testing sample; the acoustic emission sensor sends collected acoustic signals to the acoustic emission acquisition system; the camera sends collected image signal to the image acquisition control equipment; the acoustic emission sensor adopts a cylinder; a sensing surface is formed on the top surface of the cylinder; the acoustic emission sensor is fixed through the fixing device, so as to ensure that the sensing surface of the acoustic emission sensor is adhered to the surface of the testing sample. The system is simple in structure, and high in reliability and testing precision, and can effectively solve the problem in fixing the nonmagnetic material.

Description

technical field [0001] The invention belongs to the technical field of non-destructive testing, and in particular relates to a non-contact strain field and acoustic emission combined split measurement system and method. Background technique [0002] Non-destructive testing technology can monitor the defect distribution and damage development of the research object without damaging the material. For example, the measurement of the non-contact strain field can study the full-field deformation characteristics of the material during the stress process, and the test device can keep a certain distance from the test sample. The acoustic emission testing technology can monitor the damage development of the material online in real time to obtain the micro Crack initiation and propagation information, and damage localization. The combination of non-contact strain field testing technology and acoustic emission testing technology can effectively study the relationship between the damag...

AI Technical Summary

Problems solved by technology

[0004] Although many solutions for fixing acoustic emission sensors have been disclosed in the prior art, the prior art still cannot solve the problem of fixing the acoustic emission sensor during the joint test of the non-contact strain field and acoustic emission of non-magnetic materials. The main reasons are as follows: 1. Non-magnetic materials cannot use magnetic fixing method; 2. For frame fixing method, its structure is complicated

In the material mechanics experiment, the size of the test sample is generally small, so the experimental operation is difficult, and when used for the joint test of the non-contact strain field and acoustic emission, the fixture will produce a certain shielding on the surface of the test sample, resulting in the strain field measurement Unable to carry out; 3. Tape fixing method is a simple and easy method to fix the acoustic emission sensor, but in the same way, the tape will also block the test surface, so this solution cannot be used for the joint test of non-contact strain field and acoustic emission; 4 , The indirect fixation method pastes the conversion layer (plastic sleeve or metal plate) on the surface of the test sample, and then fixes the sensor through the conversion layer. The adhesive between the layer and the test sample will gradually debond, and the noise signal generated during the debonding process will affect the measurement results of acoustic emission

In addition, the transfer layer and the test sample will be jointly deformed by force during the experiment, which will affect the load indication to a certain extent, and will cause obvious deviations between the test results and the real results.

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