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Device and method for detecting interior initial stress of steel structural member based on ultrasonic method

A technology of initial stress and ultrasonic method, which is applied to measuring devices, using sound waves/ultrasonic waves/infrasonic waves to analyze solids, measure forces, etc., can solve problems such as single, inability to measure initial stress of steel structural members, and inability to detect stress. Convenience, simple structure and low cost

Active Publication Date: 2014-11-12
李祚华
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  • Summary
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  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

It mainly includes the following aspects: First, the difference in component materials. The steel used for steel structures is mainly low-carbon steel and alloy steel, while the steel used for rails in the railway industry is all special steel, and the type of steel is relatively single, and the welding residual stress In the test, the texture of the base metal will change due to the influence of temperature, which is different from the type of steel in the construction industry; secondly, the influence of component size, steel structural components, such as section steel, steel pipe, etc., have different surface morphology and component shape. Particularity, due to the influence of this factor, it is very different from the wave type and probe arrangement selected in the above method such as the axial stress detection of bolts; thirdly, the wave type selected in the above method is longitudinal wave , the combination of longitudinal and transverse waves, etc., it is impossible to measure the internal initial stress of steel structural members using these wave modes
Moreover, the current stress non-destructive testing methods for steel structural members mainly have the following disadvantages: one is that they can only detect the change in stress, but not the stress in the current state; The depth range of tens of microns, but can not detect the magnitude of the stress at the depth of several millimeters

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  • Device and method for detecting interior initial stress of steel structural member based on ultrasonic method

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Embodiment 1

[0069] Embodiment 1 The present invention is based on ultrasonic non-destructive testing of internal initial stress device composition testing method of steel structural members and explanation of related principles

[0070] The principle of the non-destructive testing method for the internal initial stress of steel structural members based on the ultrasonic method is as follows.

[0071] In the elastic range, the relationship between the stress and strain inside the material is generally considered to be a linear relationship, which is the familiar Hooke's law. As measurement techniques developed, it was discovered that elastic "constants" such as Young's modulus were not fixed but varied slightly according to the magnitude of the strain. Experiments have shown that when the atoms inside the material are compressed by compressive stress, the elastic modulus becomes larger, and when the atoms are pulled apart by tensile stress, the elastic modulus becomes smaller. These situat...

Embodiment 2

[0117] Embodiment 2 The present invention is based on the ultrasonic method for non-destructive detection of the internal initial stress device of the steel structural member for the test of the internal initial stress of the steel plate

[0118] In order to verify the accuracy of the method of the present invention for detecting the internal stress of the steel structural member, the following test and comparative test for detecting the internal initial stress of the steel structural member were done.

[0119] Select the type of steel structural member as a representative and relatively simple steel structural member—steel plate. The size of the steel plate is 600mm long, 40mm wide, and 8mm thick. The physical schematic diagram of the steel plate is as follows Figure 23 shown. In this test, the center frequency of the ultrasonic transmitting probe and receiving probe is selected as 5 MHz, that is, the axial stress value at a depth of 1.5 mm from the surface of the component ...

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Abstract

The invention provides a device and method for detecting the interior initial stress of a steel structural member based on the ultrasonic method. According to the method for detecting the interior initial stress of the steel structural member based on the ultrasonic method, the interior initial stress sigma of the steel structural member is solved by firstly calibrating the acoustic elasticity coefficient B of the fixed sonic path distance of a replica of the steel structural member in service and then detecting the change of the acoustic time t of ultrasonic waves in the steel structural member in service. An existing method for nondestructive detection of the stress of a steel structural member mainly has the disadvantages that only the change of the stress can be detected, and the intensity of the stress in the current state can not be detected; only the stress of the positions located on the surface of the steel structural member and the stress of the positions at most dozens of microns below the surface of the steel structural member can be detected, and the intensity of the stress of positions with depths of several millimeters can not be detected. The method for detecting the interior initial stress of the steel structural member based on the ultrasonic method can overcome the defects of the existing method and can be used for nondestructive detection of the interior initial stress of various steel structural members. Detections results are verified, the precision is high, the error requirement of practical engineering can be met, and the structural member can not be damaged during detection.

Description

technical field [0001] The invention belongs to the field of stress non-destructive testing of steel structural components, and in particular relates to a device and method for non-destructive testing of internal initial stress of steel structural components based on an ultrasonic method. Background technique [0002] With the rapid development of economy, more and more steel structure engineering projects are being built and planned in our country. At the same time, people are paying more and more attention to the safety of such projects. In order to ensure the safety of structures and people's lives, properties and safety, it is very necessary to carry out health monitoring of steel structures. There are many contents of structural health monitoring, such as load monitoring, temperature monitoring, acceleration monitoring, displacement monitoring, strain monitoring, stress detection and so on. The internal stress of in-service steel structure components is an important i...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01L1/25G01N29/04
Inventor 李祚华滕军何京波
Owner 李祚华
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