Universal string type strain gauge

Abstract

The utility model provides a universal string-type strain gauge, which adopts an innovative modular design, and realizes free conversion between an embedded type installation mode and a surface type installation mode through a flat structure in the middle of a metal string body and stepped cylindrical connecting parts at two ends of the metal string body in cooperation with a detachable flange plate. The integrated design effectively solves the problem of single function of the traditional strain gauge, not only retains the characteristic of rigid connection between the embedded strain gauge and the base body, but also has the advantage of rapid installation of the surface strain gauge. The standard interface design ensures the measurement precision and the force transmission reliability, and the flat structure enhances the signal stability, so that a single device can adapt to the monitoring requirements of different engineering stages, and the use flexibility and the economical efficiency are remarkably improved.

Description

Technical Field

[0001] This utility model relates to the field of structural safety monitoring technology, specifically to a general-purpose string strain gauge. Background Technology

[0002] A strain gauge is a sensor used to monitor the deformation of a structure due to changes in load and temperature. There are many types of strain gauges, such as vibrating wire strain gauges, differential resistance strain gauges, fiber optic strain gauges, and various types of resistance strain gauges.

[0003] A vibrating wire strain gauge, also known as a string strain gauge, is a sensor that measures structural strain based on the principle of string vibration. It contains a tensioned metal string (such as a steel string), whose natural vibration frequency is related to the string's tension, length, and density. When the measured structure experiences strain, the string's tension changes, causing a change in the vibration frequency. By measuring the string's resonant frequency, the strain value of the structure can be inferred.

[0004] String strain gauges are mainly divided into two types based on their installation method: embedded type and surface type. For example... Figure 1 As shown, the embedded string strain gauge 10 is typically pre-embedded in reinforced concrete or geotechnical structures, with circular plate flange structures 11 at both ends to ensure a rigid connection with the base material and effectively prevent relative slippage during the measurement process; Figure 2 As shown, the surface-type string strain gauge 20 typically employs a cylindrical connecting end 21 for easy and quick installation into a dedicated mounting bracket. Due to significant differences in structural form and installation requirements, these two types of strain gauges cannot be structurally interchangeable or universally used in existing technologies. The need to equip both types of equipment simultaneously in engineering projects increases costs and management complexity; embedded strain gauges cannot be recycled, resulting in resource waste; different installation requirements reduce construction efficiency; and differences in measurement system benchmarks may affect data consistency. These technological limitations severely restrict the application effectiveness of strain gauges in complex engineering projects, necessitating the development of a universal structure to improve economy and convenience. Utility Model Content

[0005] Based on the above description, this utility model provides a universal string strain gauge to solve the technical problem that the incompatibility between embedded and surface strain gauges in the prior art leads to increased costs and wasted resources.

[0006] The technical solution of this utility model to solve the above-mentioned technical problems is as follows:

[0007] A universal string strain gauge comprises a metal string and a flange plate, the metal string comprises a metal string body and end heads at both ends of the metal string body, the metal string body comprises a flat part at the middle and connecting parts at both ends of the flat part, the connecting parts and the end heads are cylindrical structures, the outer diameter of the connecting parts is smaller than the outer diameter of the end heads, an outer thread is formed on the outer side wall of the end head away from one end of the connecting part, and a threaded hole matched with the end head is formed in the middle of the flange plate.

[0008] Compared with the prior art, the technical scheme of the present application has the following beneficial technical effects:

[0009] The universal string strain gauge adopts innovative modular design, realizes free conversion of buried and surface installation modes through the flat structure in the middle of the metal string body and the stepped cylindrical connecting parts at both ends, and cooperates with the detachable flange plate. This integrated design effectively solves the problem of single function of traditional strain gauges, retains the characteristics of rigid connection of buried strain gauges with the base, and has the advantages of quick installation of surface strain gauges. The standardized interface design ensures the measurement accuracy and force transmission reliability, the flat structure enhances the signal stability, so that a single device can adapt to the monitoring needs of different engineering stages, and the use flexibility and economy are significantly improved.

[0010] On the basis of the above technical scheme, the utility model can also be improved as follows.

[0011] Further, the inside of the metal string is provided with a vibrating string.

[0012] Further, the vibrating string is made of high-carbon steel wire material, has a corrosion-resistant layer plated on the surface, and the natural frequency of the vibrating string has a linear relationship with the strain of the metal string body.

[0013] Further, the outside of the flat part is used for installing an electromagnetic excitation coil.

[0014] Further, a heat shrink tube is movably sleeved on the outside of the connecting part.

[0015] Further, installation grooves are symmetrically arranged on both sides of the flat part.

[0016] Further, an annular groove is formed on the outer side wall of at least one end head.

[0017] Further, mounting holes are formed on the disc surface of at least one flange plate. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a structural schematic view of the buried string strain gauge in the prior art;

[0019] Figure 2This is a schematic diagram of the structure of a surface-type string strain gauge in the prior art;

[0020] Figure 3 This is a schematic diagram of the structure of a general-purpose string strain gauge in the embodiments of this application. Detailed Implementation

[0021] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0023] like Figure 3 As shown, this application embodiment provides a general-purpose string strain gauge, which includes a metal string 30 and a flange 40. The metal string 30 includes a metal string body 31 and end caps 32 located at both ends of the metal string body 31. The metal string body 31 includes a flat portion 311 located in the middle and connecting portions 312 located at both ends of the flat portion 311. The outer side of the flat portion 311 is used to install an electromagnetic excitation coil. Specifically, mounting grooves are symmetrically arranged on both sides of the flat portion 311.

[0024] The connecting part 312 and the end 32 are cylindrical structures. The outer diameter of the connecting part 312 is smaller than the outer diameter of the end 32. An external thread 321 is formed on the outer side wall of the end 32 away from the connecting part 312. A threaded hole that mates with the end 32 is formed in the middle of the flange 40.

[0025] The metal string 31 adopts a composite structure design of a central flat part 311 and two cylindrical connecting parts 312. The flat part 311 enhances the excitation capability of the string and improves the stability of the vibration signal, while the cylindrical connecting parts 312 with stepped diameter changes form a natural stress transition zone, effectively reducing the risk of stress concentration.

[0026] The detachable connection design between the external thread 321 at end 32 and the flange 40 offers dual advantages: it ensures a rigid connection strength with the substrate during embedded installation, and allows for direct adaptation to surface mount brackets after removing the flange 40, enabling flexible conversion between installation modes. Furthermore, this modular design overcomes the limitations of traditional strain gauges with their single function. The standardized threaded interface 321 ensures measurement accuracy and force transmission reliability, while the symmetrical design of the flat section 311 guarantees the consistency of vibration signals.

[0027] In practical engineering applications, this design significantly reduces equipment procurement and maintenance costs. The ability to replace damaged parts individually extends the overall service life, and the standardized external thread 321 also leaves room for the development of industry standards and the expansion of intelligent monitoring components.

[0028] The metal string 30 has a vibrating string (not shown in the figure) inside. Preferably, the vibrating string is made of high carbon steel wire, and its surface is coated with an anti-corrosion layer. The natural frequency of the vibrating string is linearly related to the strain of the metal string body 31.

[0029] The outer side of the connecting part 312 is fixedly fitted with a heat shrink tubing 313, which provides a physical protective layer for the connecting part 312, effectively preventing mechanical scratches during installation and isolating external corrosive media. In addition, the plastic material can be customized for different working conditions (such as acid and alkali resistance, UV resistance, etc.) to adapt to complex engineering environments such as bridges and tunnels. Its insulation properties can also avoid the influence of electromagnetic interference on signal transmission.

[0030] In some embodiments, an annular groove is formed on the outer side wall of the end portion 32. When it is mounted as a surface type, the end with the annular groove is easy to fix, and the end without the annular groove is used to adjust the initial reading, which facilitates the overall installation and debugging.

[0031] In some alternative embodiments, mounting holes are formed on the flange 40, which are designed to facilitate the fixing of the strain gauge to a multi-dimensional strain gauge support when used as an embedded multi-dimensional strain gauge.

[0032] In summary, this general-purpose string strain gauge employs an innovative modular design. Through a flat structure in the middle of the metal string and stepped cylindrical connections at both ends, along with a detachable flange, it allows for seamless switching between embedded and surface mounting modes. This integrated design effectively solves the problem of traditional strain gauges having limited functionality, retaining the rigid connection between embedded strain gauges and the substrate while also possessing the advantages of rapid installation for surface strain gauges.

[0033] The above merely describes preferred embodiments of the present application and is not intended to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A universal string strain gauge, characterized by, The metal string comprises a metal string body and end heads at both ends of the metal string body, the metal string body comprises a flat part in the middle and connecting parts at both ends of the flat part, the connecting parts and the end heads are cylindrical structures, the outer diameter of the connecting parts is smaller than that of the end heads, the outer side wall of the end head is formed with external threads away from one end of the connecting part, and the middle part of the flange plate is formed with a threaded hole matched with the end head.

2. The universal string strain gauge according to claim 1, characterized in that The inside of the metal string is provided with a vibrating string.

3. The universal string strain gauge according to claim 2, wherein The vibrating string is made of high-carbon steel wire material, the surface of which is plated with an anti-corrosion layer, and the inherent frequency of the vibrating string has a linear relationship with the strain of the metal string body.

4. The universal string strain gauge according to claim 1, wherein The outside of the flat part is used for installing an electromagnetic excitation coil.

5. The universal string strain gauge according to claim 1, wherein The outside of the connecting part is fixedly sleeved with a heat shrink tube.

6. The universal string strain gauge according to claim 1, wherein The both sides of the flat part are symmetrically provided with mounting grooves.

7. The universal string strain gauge according to claim 1, wherein The outer side wall of at least one end head is formed with an annular groove.

8. The universal string strain gauge of claim 1, wherein, The disc surface of at least one flange plate is formed with a mounting hole.

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