A portable stress detection device for in-service steel bridges based on magnetic flux technology

Abstract

The invention discloses a portable in-service steel bridge stress detector based on a magnetic flux technology, and relates to the technical field of bridge health monitoring. The detector comprises a casing, a master control unit, a display screen, a magnetic induction coil, a Hall sensor and a power supply module, the side surface of the casing is rotationally connected with a support, the tail end of the support is provided with a U-shaped chuck, the Hall sensor is fixedly to the U-shaped chuck via a fastening screw, the top end of the casing is provided with an abutting head, and the bottom of the casing is provided with a handle. The detector is reliable in a detection result, clear in logics, simple in a detection method, compact in structure, convenient to carry and high in practicality.

Description

technical field [0001] The invention relates to the technical field of bridge health monitoring, in particular to a portable in-service steel bridge stress detection device based on magnetic flux technology. Background technique [0002] Long-span steel bridges have the characteristics of defect-sensitive structures. After the bridge structure is subjected to an earthquake, the material properties of the structure will change (welding heat influence, corrosion and initial defect development, etc.), and some damage will inevitably occur, making its health condition continue to deteriorate. In severe cases, its internal force and The deformation may exceed the limit, thus threatening the normal use and safety of the entire structure. [0003] One of the main reasons for the catastrophic accidents of large bridge structures is that there is no good method to monitor the stress of long-span steel structure bridges and the construction quality, damage, material changes and actua...

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Problems solved by technology

[0002] Long-span steel bridges have the characteristics of defect-sensitive structures. After the bridge structure is subjected to an earthquake, the material properties of the structure will change (welding heat influence, corrosion and initial defect development, etc.), and some damage will inevitably occur, making its health condition continue to deteriorate. In severe cases, its internal force and The deformation may exceed the limit, thus threatening the normal use and safety of the entire structure

[0003] One of the main reasons for the catastrophic accidents of large bridge structures is that there is no good method to monitor the stress of long-span steel structure bridges and the construction quality, damage, material changes and actual stress conditions of key parts of the structure. Real-time online non-destructive testing or monitoring, existing traditional testing techniques and methods are difficult to solve this problem, mainly due to the following reasons: ①Due to the limitations of existing conventional testing The complexity of structure and material properties makes it difficult for traditional testing techniques to be directly applied to on-site non-destructive testing or monitoring of actual engineering structures. Although there are on-site monitoring methods for embedded pressure cells or other testing devices, generally these embedded tests The devices are disposable and difficult to reuse. It is difficult to change the measuring point or replace the test device and the non-destructive testing of the upper structure rods, and most of them contain polymer materials, metal wires or glue in the production process. Therefore, the service life is not long, the operation is difficult and the cost is high, and it is difficult to promote and apply in a large area; ②The traditional structural detection technology is mainly based on the measured deformation or local strain of structural components, and uses its constitutive relationship to determine the structural components. Therefore, it is necessary to understand and master the loading history or process of structural components, which is very difficult, sometimes even impossible, for on-site non-destructive testing of in-service structural material changes or actual stress states; ③ from the current From the perspective of research and application, there are still many problems in the application of existing structural non-destructive testing technology in actual engineering. Some methods are not perfect enough, and the detection effect is also very limited. Application and promotion of non-destructive testing and diagnostic technology

At present, many scholars at home and abroad have done a lot of research work on the theory and application technology of non-destructive testing of bridge structures. However, there are few related researches on non-destructive testing of long-span steel bridges based on the theory of magnetic-mechanical coupling stress testing.

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