Optical fiber ring type residual stress test system and residual stress test method

Abstract

The invention discloses an optical fiber ring type residual stress testing system, which comprises a plurality of optical fiber sensors, a transmission optical fiber, a demodulation device and a dataprocessing device, the optical fiber sensors are connected in series through transmission optical fibers and wound into a circle to form an optical fiber sensor ring, the optical fiber sensor ring isfixed to the surface of a to-be-measured material and connected into the demodulation device through the transmission optical fibers, and the demodulation device is electrically connected with the data processing device. The optical fiber sensor is used for testing wavelength signals of measuring points before and after drilling; the optical fiber sensor ring is used for measuring wavelength signals and transmitting the measured wavelength signals to the demodulating device through the transmission optical fiber, the demodulating device is used for demodulating and recording the wavelength signals measured by all optical fiber sensors on the optical fiber sensor ring and outputting the wavelength signals to the data processing device, and the data processing device is used for processing and analyzing data output by the demodulating device. The system provided by the invention can effectively reduce the installation difficulty of the strain sensor during a drilling method test, reducesthe error influence caused by operation, and improves the test precision.

Description

technical field [0001] The invention relates to the technical field of residual stress testing, in particular to an optical fiber ring type residual stress testing system and a residual stress testing method. Background technique [0002] Residual stress refers to the stress that still exists inside the material after various external factors (external force, temperature change, processing, etc.) that generate stress are removed. The residual stress will cause the initial damage to further evolve and reduce the mechanical properties of the material. Under sustained loading, various forms of damage grow further, eventually leading to material failure. [0003] At present, the residual stress test methods can be divided into two categories: destructive test method and non-destructive test method according to whether the tested component is damaged. The destructive test method is to remove or separate a part of the component with residual stress to release the internal stress...

AI Technical Summary

Problems solved by technology

Its disadvantage is that it is easy to tilt the angle during the actual patch, so that the axis of the strain gauge is not on the radius with the center of the drilled hole as the center, which causes a large error between the test results and the actual results. After the method test is completed, if you want to improve the accuracy, you must measure the actual patch deviation angle of the strain gauge and then bring it into the formula to correct this deviation for conversion.

On the one hand, this increases the difficulty and complexity of the drilling process, on the other hand, it also reduces the test accuracy

Secondly, if multiple sensors are placed to verify the test results, it is inconvenient to connect multiple resistance strain gauges, and the number that can be placed is limited by the size of the sensors, so it is impossible to test the overall distribution of internal stress in the material

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