Device and method for detecting internal initial stress of steel structure components based on ultrasonic method

Abstract

The invention provides a device and method for non-destructive detection of initial stress inside a steel structural member based on the ultrasonic method, which includes firstly calibrating the acoustic elastic coefficient B of the fixed sound path of the replica of the in-service steel structural member, and detecting the ultrasonic in-service steel structural member The method of solving the internal initial stress σ of the steel structure member by the change of the acoustic time t. The current non-destructive testing method for stress of steel structure members mainly has the following disadvantages: one is that it can only detect the change of stress, but not the magnitude of stress in the current state; The depth range of microns cannot detect the magnitude of stress at a depth of several millimeters. The method proposed by the invention can overcome the above-mentioned difficulties, and can be applied to the non-destructive detection of the internal initial stress of various steel structure components. The detection results have been verified, with high precision, which can meet the error requirements in actual engineering, and will not cause damage to structural components during the detection process.

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...

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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