A detection method of bolt fastening surface pressure based on FBG sensor

Abstract

The invention belongs to the technical field of joint surface pressure detection of connectors, and provides a method for detecting the surface pressure of bolt fastening joints based on an FBG sensor, which converts the joint surface pressure into the strain of the FBG sensor: the strain based on the embedded FBG sensor The transfer theory determines the size and position of the embedding groove of the FBG sensor; the pressure at the measurement point of the joint surface is determined based on the pressure distribution theory of the joint surface of the single bolt connection, and the calibration is completed corresponding to the strain and pressure values ​​in real time, so as to realize the accurate detection of the surface pressure of the joint surface. Determining the size and position of the embedding groove of the FBG sensor according to the above method can ensure the reliability and accuracy of the strain information; the comprehensive determination of the joint surface pressure can obtain an accurate strain-joint surface pressure curve, which provides a basis for studying the pressure of the bolted joint joint surface A practical and feasible method.

Description

technical field [0001] The invention belongs to the technical field of joint surface pressure detection of connectors, and specifically relates to a method for indirectly reflecting the joint surface pressure by detecting the strain of the joint surface by an FBG sensor. Background technique [0002] In the assembly of major engineering equipment parts and high-precision parts, bolted connections are often used, but it has been difficult to accurately control the bolt pretightening force and the pressure of the connection joint surface, the pressure control on the joint surface is inaccurate, and the pressure on the joint surface after installation Uneven distribution will seriously affect the stiffness of the connection and the overall performance of the equipment. In the assembly of major equipment, such as high-pressure and low-pressure turbine shafts in aero-engines, high-pressure compressor discs and drums, there are a large number of bolt connections, and the connection...

AI Technical Summary

Problems solved by technology

[0004] Aiming at the disadvantages of the above detection methods, the present invention proposes a new and reliable method for detecting the joint surface pressure. Because ultrasonic detection is easily interfered by external factors, the detection accuracy is low, and external factors such as noise have little influence on the detection of FBG sensors. , and it directly detects the magnitude of the strain, with high precision, which greatly improves the detection accuracy; after using this inventive method for calibration, the specific value of the joint surface pressure can be effectively detected with minimal damage to the joint surface , avoiding the disadvantages of embedding pressure sensors at the joint surface, so this method has strong practical value

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