Embedded grating strain gauge for concrete

Abstract

The utility model discloses an embedded grating strain gauge for concrete. The embedded grating strain gauge comprises a sleeve, two end sleeves, a holding sleeve and a strain gauge body. According to the utility model, the sleeve used for accommodating the strain gauge body and the end sleeves arranged at the two ends of the sleeve are arranged, the middle part of the sleeve is provided with the holding sleeve, and the end sleeves and the holding sleeve are respectively provided with the raised line I and the raised line II; the first protruding strip and the second protruding strip can increase the contact area so as to increase the bonding strength of the strain gauge and concrete, the sleeve and the strain gauge body in the sleeve can be fully protected through the end sleeve and the holding sleeve, and when an operator uses strain timing, the holding sleeve can be held by the hand, so that the strain gauge is convenient to use. The second protruding strips on the holding sleeve can be used for increasing friction force, and using is safer and more stable.

Description

Technical Field

[0001] The utility model belongs to the technical field of grating strain gauges, and in particular relates to an embedded grating strain gauge for concrete. Background Art

[0002] Fiber Bragg strain gauge is the most widely used and most mature fiber sensor in the engineering field. The sensing process based on fiber Bragg obtains sensing information by modulating the Bragg wavelength of the fiber by external physical parameters. It is a wavelength modulated fiber sensor. Strain directly affects the wavelength drift of fiber Bragg. When the working environment is good or the structure to be measured requires a small sensor, people use bare fiber Bragg as a strain sensor to directly stick it on the surface of the structure to be measured or bury it inside the structure. Fiber Bragg sensors can perform health detection on structures, etc.

[0003] Please refer to the patent document with application number 202221844775.3, which discloses a buried grating strain gauge for concrete, including: a grating strain gauge body and a coating arranged on the outside of the grating strain gauge body; the coating is a hollow structure, and the coating completely wraps the grating strain gauge body; both ends of the grating strain gauge body are electrically connected with optical fibers; the optical fibers pass through and extend out of the coating; the coating is pre-buried in concrete. The coating in this application isolates the grating strain gauge body from the outside, so that it is not affected by external interference in engineering practice such as electromagnetics, and can accurately measure the internal strain of concrete; the spiral protrusion can also enhance the bonding between the entire strain gauge and the concrete.

[0004] In the above-mentioned prior art solution, although the grating strain gauge is protected by providing a coating body and a spiral protrusion is provided to increase the bonding strength, it still has some defects in application, such as insufficient protection of the middle area, which is easy to be damaged during installation or transportation. Utility Model Content

[0005] The utility model aims to provide an embedded grating strain gauge for concrete to solve the problems raised in the above background technology.

[0006] To achieve the above-mentioned purpose, the utility model provides the following technical solution: an embedded grating strain gauge for concrete, comprising:

[0007] casing;

[0008] Two end sleeves are respectively fixed at two ends of the sleeve, and the outer surface of the end sleeve is fixed with a plurality of convex strips arranged at intervals in the circumferential direction;

[0009] A gripping sleeve, which is fixed on the middle part of the sleeve and has a plurality of convex strips 2 fixed on the outer surface thereof and distributed at intervals in the circumferential direction;

[0010] The strain gauge body is built into the sleeve, and is connected to an optical fiber at both ends respectively. The two optical fibers pass through the two end sleeves respectively and extend to the outside.

[0011] Preferably, the end sleeve has a sealing fixing sleeve which is sleeved with the sleeve;

[0012] The sealing fixing sleeve is fixed with a plurality of locking bolts which are evenly spaced and distributed in the circumferential direction; the ends of the locking bolts pass through the sleeve and are threadedly connected with a fixing nut.

[0013] Preferably, an elastic extension sleeve is provided on a side of the end sleeve away from the sleeve, a gap is provided at the center of the elastic extension sleeve for the optical fiber to pass through, and an inner wall is tightly connected to the optical fiber.

[0014] Preferably, a plurality of support frames are provided in the sleeve and are respectively located on both sides of the strain gauge body;

[0015] The support frame is a semicircular frame, which consists of a semicircular first support rod in contact with the sleeve and a second support rod in contact with the strain gauge body; two ends of the first support rod are fixedly connected to two ends of the second support rod.

[0016] Preferably, the convex strip 1 and the convex strip 2 are both arc-shaped strips, and two adjacent convex strips 1 and two adjacent convex strips 2 are symmetrically arranged.

[0017] Preferably, the first support rod and the second support rod are integrally formed.

[0018] Technical effects and advantages of the utility model:

[0019] (1) In the present invention, a sleeve for accommodating a strain gauge body and end sleeves are provided at both ends of the sleeve, and a holding sleeve is provided in the middle of the sleeve, and convex strips 1 and 2 are provided on the end sleeve and the holding sleeve, respectively. The convex strips 1 and 2 can increase the contact area to increase the bonding strength between the strain gauge of the present invention and the concrete, and the end sleeve and the holding sleeve can also provide sufficient protection for the sleeve and the strain gauge body in the sleeve. When the operator uses the strain gauge, the holding sleeve can be held by hand, and the convex strips 2 on the holding sleeve can be used to increase friction, making the use safer and more stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0021] Figure 2 It is a schematic diagram of the internal structure of the sleeve of the utility model.

[0022] In the figure:

[0023] 1. Sleeve; 2. End sleeve; 21. Raised strip 1; 22. Sealing fixing sleeve; 221. Locking bolt; 23. Elastic extension sleeve; 3. Holding sleeve; 31. Raised strip 2; 4. Strain gauge body; 5. Support frame; 6. Optical fiber. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0025] The utility model provides Figure 1-Figure 2 The embedded grating strain gauge for concrete shown in the figure comprises a sleeve 1, two end sleeves 2, a holding sleeve 3 and a strain gauge body 4.

[0026] The two end sleeves 2 are respectively fixed at the two ends of the sleeve 1, and the outer surface of the end sleeve 2 is fixed with a plurality of convex strips 21 arranged at circumferential intervals.

[0027] See also Figure 1 The end sleeve 2 can be a square sleeve or a round sleeve. In this embodiment, the outer contour of the end sleeve 2 is a square, and four convex strips 21 are provided on one side, and a total of eight convex strips 21 are provided on the four sides. The convex strips 21 can increase the bonding strength between the end sleeve 2 and the concrete after being buried.

[0028] Furthermore, the end sleeve 2 has a sealing fixing sleeve 22 which is sleeved with the sleeve 1; the sealing fixing sleeve 22 is fixed with a plurality of locking bolts 221 which are evenly spaced in the circumferential direction; the end of the locking bolt 221 passes through the sleeve 1 and is threadedly sleeved with a fixing nut. The sealing fixing sleeve 22 is sleeved with the sleeve 1 and fixed by four locking bolts 221, so that the sleeve 1 can be stably installed on the end sleeve 2, and installation and disassembly are convenient.

[0029] In addition, an elastic extension sleeve 23 is provided on one side of the end sleeve 2 away from the sleeve 1, the center of the elastic extension sleeve 23 has a gap for the optical fiber 6 to pass through, and the inner wall is tightly connected to the optical fiber 6. The elastic extension sleeve 23 can bundle the optical fiber 6 to ensure the stability of the optical fiber 6.

[0030] The gripping sleeve 3 is fixedly mounted on the middle part of the sleeve 1, and a plurality of convex strips 31 are fixedly disposed on the outer surface thereof. The operator moves and installs the sleeve 1 by holding the gripping sleeve 3 by hand, and the convex strips 31 can increase the stability of holding.

[0031] The strain gauge body 4 is built into the sleeve 1 , and is connected to an optical fiber 6 at both ends respectively. The two optical fibers 6 pass through the two end sleeves 2 respectively and extend to the outside.

[0032] In order to improve the stability of the strain gauge body 4, a plurality of support frames 5 are provided in the sleeve 1 and are respectively located on both sides of the strain gauge body 4; the support frame 5 is a semicircular frame, which consists of a semicircular arc-shaped first support rod in contact with the sleeve 1 and a second support rod in contact with the strain gauge body 4; the two ends of the first support rod are fixedly connected to the two ends of the second support rod. The first support rod and the second support rod are integrally formed. The support frames 5 on both sides of the strain gauge body 4 correspond to each other one by one, and form a circular frame with each other, which can provide support and protection for the strain gauge body 4.

[0033] It should be supplemented that the first convex strip 21 and the second convex strip 31 are both arc-shaped strips, and two adjacent first convex strips 21 and two adjacent second convex strips 31 are symmetrically arranged.

[0034] Working principle: The utility model is a concrete embedded grating strain gauge. When in use, the operator holds the grip sleeve 3 by hand to move and install the sleeve 1. The convex strip 2 31 can increase the stability of the grip, and the convex strip 1 21 can increase the bonding strength between the end sleeve 2 and the concrete after embedding. The support frames 5 on both sides of the strain gauge body 4 form a circular frame to provide support and protection for the strain gauge body 4.

[0035] Finally, it should be noted that the above is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present utility model shall be included in the protection scope of the present utility model.

Claims

1. An embedded grating strain gauge for concrete, characterized in that: include: Casing (1); Two end sleeves (2) are respectively fixed at two ends of the sleeve (1), and the outer surface of the end sleeve (2) is fixed with a plurality of convex strips (21) arranged at intervals in the circumferential direction; A gripping sleeve (3) which is sleeved and fixed on the middle part of the sleeve (1) and has a plurality of convex strips (31) fixed on its outer surface and distributed at intervals in the circumferential direction; The strain gauge body (4) is built into the sleeve (1) and is respectively connected to an optical fiber (6) at both ends. The two optical fibers (6) respectively pass through the two end sleeves (2) and extend to the outside.

2. The embedded grating strain gauge for concrete according to claim 1, characterized in that: The end sleeve (2) is provided with a sealing fixing sleeve (22) sleeved with the sleeve (1); The sealing fixing sleeve (22) is fixed with a plurality of locking bolts (221) evenly spaced in the circumferential direction; the ends of the locking bolts (221) pass through the sleeve (1) and are threadedly sleeved with a fixing nut.

3. The embedded grating strain gauge for concrete according to claim 1, characterized in that: An elastic extension sleeve (23) is provided on the side of the end sleeve (2) away from the sleeve (1); a gap is provided at the center of the elastic extension sleeve (23) for the optical fiber (6) to pass through, and the inner wall is tightly connected to the optical fiber (6).

4. The embedded grating strain gauge for concrete according to claim 1, characterized in that: A plurality of support frames (5) are arranged in the sleeve (1) and are respectively located on both sides of the strain gauge body (4); The support frame (5) is a semicircular frame, comprising a semicircular arc-shaped first support rod in contact with the sleeve (1) and a second support rod in contact with the strain gauge body (4); the two ends of the first support rod are fixedly connected to the two ends of the second support rod.

5. The embedded grating strain gauge for concrete according to claim 1, characterized in that: The convex strip 1 (21) and the convex strip 2 (31) are both arc-shaped strips, and two adjacent convex strips 1 (21) and two adjacent convex strips 2 (31) are symmetrically arranged.

6. The embedded grating strain gauge for concrete according to claim 4, characterized in that: The first support rod and the second support rod are integrally formed.

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