CN220690396U

CN220690396U - Steel structure fatigue crack stop hole failure early warning device

Info

Publication number: CN220690396U
Application number: CN202322462877.XU
Authority: CN
Inventors: 王秋东; 史山春; 王志强
Original assignee: Nanjing Forestry University
Current assignee: Nanjing Forestry University
Priority date: 2023-09-11
Filing date: 2023-09-11
Publication date: 2024-03-29
Anticipated expiration: 2033-09-11

Abstract

The drilling crack-arresting technology is often used for temporary crack-arresting of fatigue cracks of the steel structure, but the judgment of the working state of the crack-arresting hole is still mainly solved by means of manual visual observation, and the working efficiency is low and the observation precision is poor. The utility model discloses a steel structure fatigue crack-stopping hole failure early warning device which comprises an elastic loop sleeve and a device main body, wherein the elastic loop sleeve comprises a thin copper sheet which can be adhered to the inner wall of a crack-stopping hole, a power supply, a judging circuit and an LED lamp are arranged in the device main body, and the elastic loop sleeve is connected with the device main body through a loop plug and a loop slot. The method is favorable for timely and accurately judging whether the inner wall of the crack-stopping hole is cracked or not, and solves the problem that the secondary cracking of the crack-stopping hole is difficult to be found in time in practical engineering application.

Description

Steel structure fatigue crack stop hole failure early warning device

Technical Field

The utility model relates to the technical field of steel structures, in particular to a steel structure fatigue crack stop hole failure early warning device.

Background

For steel structures (especially welded steel structures), fatigue cracking problems are common and difficult to avoid. Once the steel structure is subjected to fatigue cracking, the fatigue cracking can rapidly expand until the components are broken, and the overall safety of the structure is seriously threatened. As a temporary crack stop measure, the technique of drill hole crack stop is often used for crack stop maintenance of fatigue cracks of steel structures. But under the repeated loading, the crack will re-initiate at the inner wall (or edge) of the crack-stopper hole and rapidly propagate. Therefore, the working state of the crack-stopping hole is accurately mastered, effective measures are timely taken to further strengthen fatigue cracks, and the method is very important for prolonging the service life of the steel structure. However, currently, the working state of the crack stopper hole is often judged by adopting a manual visual detection mode, which mainly has the following two defects: (1) For the crack-stopping holes at higher positions (such as the crack-stopping holes at the welding seam of the top plate and the U-rib of the steel box girder of the large-span bridge, the ground clearance is usually about 2.5-3 meters), observation is needed by means of a herringbone ladder, the efficiency of the process of carrying the herringbone ladder and climbing up and down in the inspection process is low, and potential safety risks exist; (2) Manual observation is usually carried out by eyes and a magnifying glass, and only cracks which are secondarily expanded to a certain length can be observed, so that the cracks on the inner wall (edge) of the crack-stopping hole are difficult to capture, and the gold window period for secondary reinforcement of the cracks is missed. Therefore, a device capable of monitoring the working state of the fatigue crack-stopping hole of the steel structure in real time is developed and proposed, and is very necessary.

Disclosure of Invention

The utility model aims to: the utility model provides a steel structure fatigue crack-stopping hole failure early warning device, which solves the problem that the working state (normal or failure) of a crack-stopping hole is difficult to judge in time in actual engineering.

The technical scheme is as follows: the utility model discloses a steel structure fatigue crack-stopping hole failure early warning device which comprises an elastic loop sleeve and a device main body, wherein the elastic loop sleeve comprises a thin copper sheet which can be adhered to the inner wall of a crack-stopping hole, a power supply, a judging circuit and an LED lamp are arranged in the device main body, and the elastic loop sleeve is connected with the device main body through a loop plug and a loop slot.

The steel structure fatigue crack-stopping hole failure early warning device is used for early warning of crack-stopping hole failure in actual engineering.

For monitoring the working state of the crack stopper hole, the elastic ring sleeve comprises a thin copper sheet and a loop plug, wherein Bao Tongpian is adhered to the inner wall of the crack stopper hole through glue and used for monitoring the secondary cracking condition of the crack stopper hole, and the loop plug is connected with the thin copper sheet and used for connecting the thin copper sheet into a circuit loop.

In order to indicate the crack stopper operating condition, the device main body comprises an LED green light, an LED red light and a loop slot, the loop slot can be connected with a loop plug, a thin copper sheet is connected into a circuit loop, and the LED green light, the LED red light, the thin copper sheet and a power supply in the device main body jointly form a judging circuit, so that the indication of different operating conditions of the crack stopper can be realized.

The beneficial effects are that: 1. the utility model has simple structure and easy installation; 2. through the indication of the LED lamp, a worker can clearly see the working state of the crack stopper hole without climbing, so that the working efficiency is improved, and the personal safety hazard caused by high-altitude climbing is avoided; 3. the secondary cracking condition of the crack-stopping hole can be timely monitored, and secondary reinforcement measures can be timely taken.

Drawings

FIG. 1 is a schematic view of a fatigue crack and crack stop hole of a steel structure;

FIG. 2 is a schematic view of an elastic collar of the present utility model;

FIG. 3 is a schematic view of the device body of the present utility model;

FIG. 4 is a schematic view of the present utility model in a pre-installation state;

FIG. 5 is a schematic view of the utility model monitoring the operation of the crack stopper.

Detailed Description

Referring to fig. 1 to 5, the steel structure fatigue crack-arresting hole failure early warning device according to an embodiment of the utility model includes an elastic loop 4, wherein the elastic loop 4 includes a copper sheet 5 and a loop plug 61 connected with a device body 7.

The device main body 7 comprises a loop slot 62 matched with the loop plug, an LED green light 8 for indicating that the working state of the crack stopper hole is normal, and an LED red light 9 for indicating that the crack stopper hole is invalid.

The working steps of the utility model are as follows:

the surface of the steel plate 1 is provided with a fatigue crack 2, and a crack stopper 3 is drilled at the tip of the fatigue crack 2.

Before installation, the inner wall of the crack stopper hole 3 is polished in advance to remove burrs and the like generated in the drilling process. And then, quick-drying glue (such as 502 glue) is smeared on the inner wall of the crack stopper hole 3, and the elastic ring sleeve 4 is inserted into the crack stopper hole 3, so that the thin copper sheet 5 is ensured to be clung to the inner wall of the crack stopper hole 3 until the glue is solidified.

The loop slot 62 on the device main body 7 is aligned with the loop plug 61 on the elastic loop sleeve 4 and is pressed in, at the moment, the thin copper sheet 5 and the device main body 7 form a loop, the LED green light 8 works, the LED red light 9 does not work under the action of a circuit inside the device main body 7, and at the moment, the crack stop hole 3 is in a normal working state.

If the crack stopper 3 cracks secondarily, the Zhang Gehui with the opening on the surface of the crack tears the thin copper sheet 5, at the moment, the loop formed by the thin copper sheet 5 and the device main body 7 is disconnected, the LED green light 8 does not work, the LED red light 9 works through the circuit inside the device main body 7, and at the moment, the crack stopper 3 is in a failure state.

Claims

1. A steel structure fatigue crack arrest hole inefficacy early warning device which characterized in that: the device comprises an elastic loop (4) and a device main body (7), wherein the elastic loop (4) is connected with the device main body (7) through a loop plug (61) and a loop slot (62).

2. The steel structure fatigue crack stopper hole failure warning device according to claim 1, wherein: the outside of the elastic ring sleeve (4) is connected with a thin copper sheet (5), and the Bao Tongpian (5) is connected with a loop plug (61).

3. The steel structure fatigue crack stopper hole failure warning device according to claim 1, wherein: an LED green light (8) and an LED red light (9) are arranged on the device main body (7).

4. The steel structure fatigue crack stopper hole failure warning device according to claim 1, wherein: the outer diameter of the elastic ring sleeve (4) is equal to or slightly smaller than the radius of the crack-stopping hole (3).

5. The steel structure fatigue crack stopper hole failure warning device according to claim 1, wherein: the inner diameter of the elastic ring sleeve (4) is equal to or slightly larger than the outer diameter of the device main body (7).