A strain gauge device that can improve the sensitivity and accuracy of strain measurement.

Abstract

This invention relates to the field of sensor technology and discloses a strain gauge device that improves the sensitivity and accuracy of strain measurement. The strain gauge device comprises three modules—module A, module B, and module C—stacked vertically. Module B, located in the middle, is the core of the structure and directly contacts the object being measured; module B is made of a low-elastic-modulus intermediate material. Modules A and C are located on either side and symmetrically arranged. The dimensions of module C are the same as those of module A. The strain gauge device provided by this invention reduces the influence of lateral strain through an overhead iron block technology, enhances the detection capability of resistance changes, reduces errors caused by surface unevenness, and maintains high measurement sensitivity. Furthermore, the replaceable intermediate material technology enables the strain gauge to be reused, offering advantages in reducing cost and resource consumption.

Description

Technical Field

[0001] This invention relates to the field of sensor technology, and in particular to a strain gauge device that can improve the sensitivity and accuracy of strain measurement. Background Technology

[0002] Strain gauges, as an important component of modern sensing technology, are widely used in various fields such as industrial automation, aerospace, and civil engineering to accurately measure the deformation of objects under stress. As a core component of modern sensing technology, the core function of a strain gauge is to accurately convert the minute deformations of an object under stress into quantifiable electrical signals, thereby enabling real-time monitoring of key parameters such as structural health and stress distribution.

[0003] The design principle of strain gauges is based on the strain effect, which states that when a conductor or semiconductor material undergoes mechanical deformation under external force, its resistance value changes accordingly. This phenomenon is called the "strain effect," while the working principle of semiconductor strain gauges is based on the "piezoresistive effect," which states that the resistivity of a semiconductor material changes when it is subjected to force along a certain axis.

[0004] Specifically, strain gauges are typically made of metal resistance wire or foil and are attached to the surface of the object whose strain needs to be measured. When the object is subjected to force and deforms, the strain gauge also deforms, and its resistance value changes accordingly. This change in resistance can be measured by a Wheatstone bridge circuit, converted into a voltage signal output, and then the strain value can be calculated based on the change in resistance.

[0005] The working principle of a resistance strain gauge can be expressed by the following formula:

[0006]

[0007] Where ε represents strain, ΔR is the change in resistance, Ro is the initial resistance of the strain gauge, and Ks represents the strain sensitivity coefficient of the resistance strain gauge.

[0008] However, under high-strain conditions, the accuracy of strain gauges is affected by key factors such as material nonlinearity, transverse effects, temperature influence, mechanical hysteresis and creep, installation and bonding issues, and dynamic response limitations. This is because: in high-strain measurements, strain gauges may be affected by transverse strain, causing the resistance change to not fully reflect the axial strain, resulting in measurement deviations. Simultaneously, due to material nonlinearity, plastic deformation or damage can lead to inaccurate measurements based on linear designs of the strain gauges, especially in high-strain regions.

[0009] Furthermore, the measurement accuracy of strain gauges can be affected by the surface structure of the object being measured. This is because the working principle of a strain gauge is based on changes in resistance, which are directly related to the deformation of the object's surface. Surface roughness and curvature have a significant impact on the measurement accuracy of strain gauges. Excessive roughness may lead to uneven contact between the strain gauge and the measurement surface, unstable adhesion, and the introduction of measurement errors; air gaps may affect the stability of the results due to strain changes. Surface curvature may cause uneven strain distribution under the strain gauge, especially under large strains, which can easily cause deviations, and even lead to stress concentration or strain gauge damage.

[0010] In addition, due to their physical properties, existing resistance strain gauges may suffer fatigue damage after repeated loading and unloading, leading to performance degradation and making them unusable. Existing strain gauges are generally considered single-use devices, primarily because once they are attached to the surface of the object being measured using specific adhesives, they are difficult to remove without damaging the sensing grid. Damage to the sensing grid directly affects the strain gauge's measurement capability, and even if it is not damaged, a strain gauge that has been removed and reattached cannot guarantee its original precise position and orientation, potentially leading to inaccurate measurement results.

[0011] Therefore, it is necessary to provide a strain gauge device that can improve the sensitivity and accuracy of strain measurement to solve the above-mentioned technical problems. Summary of the Invention

[0012] To address the common technical problems of traditional strain gauges, such as limited sensitivity, poor environmental adaptability, and high resource consumption (e.g., non-reusability), this invention provides a strain gauge device that improves the sensitivity and accuracy of strain measurement. By introducing innovative overhead iron block technology and replaceable intermediate material technology, this invention aims to fundamentally solve the aforementioned problems. This design not only significantly improves the measurement accuracy and sensitivity of the strain gauge, ensuring the accuracy and reliability of the measurement data, but also enables convenient replacement of intermediate materials through modular design, significantly enhancing the environmental adaptability and reusability of the strain gauge and reducing long-term maintenance costs.

[0013] The strain gauge device provided by this invention, which improves the sensitivity and accuracy of strain measurement, consists of three modules—module A, module B, and module C—stacked vertically. Module B, located in the middle, is the core of the structure and is used to directly contact the object being measured. Module B is made of a low-elastic-modulus intermediate material. Modules A and C are located on either side and are symmetrically arranged. The dimensions of module C are the same as those of module A, ensuring balance and uniform stress distribution during use. The strain gauge is attached to module B. The combination of the strain gauge and the low-elastic-modulus characteristics of module B, along with the high stiffness contrast between modules A and C, significantly improves the sensitivity and accuracy of strain measurement.

[0014] Preferably, the material of module B is replaceable. By selecting materials with different physical properties to replace the original marble module, the stiffness characteristics and strain measurement sensitivity of the entire device can be adjusted, thereby adapting to different testing requirements and application scenarios.

[0015] Preferably, both module A and module C are precision-machined from a single rectangular block of sturdy and durable stainless steel, ensuring the stability and strength of the overall structure.

[0016] Preferably, the original dimensions of modules A and C are 27mm in length, 14mm in width, and 12mm in height, and a rectangular area with an internal dimension of 17mm in length and 3mm in height is cut out, thereby forming the unique geometric shape of modules A and C. Through this unique geometric design, the influence of lateral strain on the measurement results is effectively reduced, while the ability of the strain gauge to detect small deformations is enhanced.

[0017] Preferably, module B is a rectangle with a length of 17mm, a width of 14mm, and a height of 5mm, located between module A and module C.

[0018] Preferably, the elastic modulus of module B is similar to that of the object being measured, so as to adapt to the measurement requirements of different objects being measured.

[0019] Compared with related technologies, the strain gauge device provided by this invention, which improves the sensitivity and accuracy of strain measurement, has the following beneficial effects:

[0020] 1. To address the drawback of decreased accuracy in existing technologies over large strain ranges, this invention employs an innovative suspended iron block technology. This effectively reduces the impact of transverse strain on measurement results and minimizes interference from the nonlinear properties of materials in high-strain regions. This technology significantly enhances the detection capability of minute changes in resistance, thereby achieving a substantial improvement in measurement accuracy. This refined measurement method not only improves the reliability of experimental results but also ensures data accuracy, providing solid data support for engineering and scientific research.

[0021] 2. To address the drawback of being susceptible to the influence of the surface structure of the measured object, this invention cleverly utilizes a suspended iron block technology to contact the measured object, effectively avoiding the reduction in strain gauge sensitivity caused by surface roughness and curvature. This technology reduces contact points, minimizing errors caused by surface unevenness. Simultaneously, the suspended design reduces uneven stress distribution caused by surface curvature, thus ensuring high sensitivity and data accuracy in the measurement process. Furthermore, the application of the suspended iron block can reduce measurement deviations caused by uneven pressure on the contact surface, further improving the reliability and accuracy of the measurement results.

[0022] 3. Addressing the drawback of existing strain gauges being non-reusable, this invention employs an innovative replaceable intermediate material technology, successfully achieving the recycling and reuse of strain gauges and avoiding damage to their performance. Traditionally, once a strain gauge is applied, it is difficult to remove it from the surface of the object being measured without damage. Even if removal is successful, re-applied strain gauges often fail to maintain the same position and orientation as when first used, thus affecting the accuracy of measurement results. This technology enables the recycling of strain gauges through intermediate materials, reducing costs and resource consumption while ensuring measurement accuracy, thus meeting the requirements of sustainable development. Attached Figure Description

[0023] Figure 1 A front view of a strain gauge device that can improve the sensitivity and accuracy of strain measurement according to the present invention;

[0024] Figure 2 A top view of a strain gauge device that can improve the sensitivity and accuracy of strain measurement, provided by the present invention;

[0025] Figure 3 A side view of a strain gauge device that can improve the sensitivity and accuracy of strain measurement according to the present invention;

[0026] Figure 4 This is a graph showing the experimental data of the present invention;

[0027] Figure 5 This is a simplified diagram of the experimental model of the present invention;

[0028] Figure 6 This is an experimental sample diagram of the present invention;

[0029] Figure 7 This is a three-dimensional sample drawing of the component of the present invention. Detailed Implementation

[0030] First, the design principle of this invention will be explained:

[0031] When two materials with significantly different stiffnesses are combined to form a composite material, we can generally expect the material with lower stiffness to bear more deformation. This is because, under the same external force, the material with lower stiffness will experience greater strain and exhibit greater deformation.

[0032] This specially designed strain gauge features a stiffness distribution that is engineered to create a structure with lower stiffness in the middle region and higher stiffness at both ends. This design allows the strain gauge to undergo greater deformation in the middle region due to its lower stiffness, while the deformation in the end regions is smaller due to their higher stiffness. This stiffness difference causes strain to concentrate in the middle region, meaning that the strain gauge's resistance change primarily reflects the strain state in the middle region.

[0033] The key advantage of this design lies in its ability to improve the sensitivity and accuracy of strain measurements. Due to the strain concentration in the central region, even minute strains can be effectively detected and amplified, enabling the strain gauge to respond to these difficult-to-detect minute strains. Furthermore, this design helps reduce measurement errors caused by structural complexity or areas where strain is difficult to measure directly.

[0034] (In practical applications, this strain gauge can be attached to critical areas of the object being measured, utilizing its high sensitivity to achieve accurate measurement of local strain. This strain gauge design is particularly suitable for applications requiring monitoring of local strain concentration or material fatigue, providing engineers with a powerful tool to ensure the safety and reliability of structures.)

[0035] The apparatus of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0036] like Figure 1 As shown, the strain gauge device provided by the present invention, which can improve the sensitivity and accuracy of strain measurement, is composed of three modules, module A, module B, and module C, stacked vertically:

[0037] Modules A and C are located on opposite sides and symmetrically arranged. Module C has the same structure and dimensions as Module A, ensuring balance and uniform stress distribution during use. Both Modules A and C are precision-machined from a single rectangular, sturdy, and durable stainless steel block, ensuring the stability and strength of the overall structure. The original dimensions of Modules A and C are 27mm in length, 14mm in width, and 12mm in height. A rectangular area with internal dimensions of 17mm in length and 3mm in height is cut out, thus forming the unique geometric shapes of Modules A and C (e.g., ...). Figure 1 As shown in the figure, this unique geometric design effectively reduces the influence of lateral strain on the measurement results, while enhancing the strain gauge's ability to detect minute deformations.

[0038] Module B, located in the middle, is the core of the structure and is used for direct contact with the object being measured. Module B is made of a low-elastic-modulus intermediate material. Strain gauges are attached to Module B. The combination of the strain gauges and the low-elastic-modulus characteristics of Module B, along with the high stiffness contrast between Module A and Module C, significantly improves the sensitivity and accuracy of strain measurement. The material of Module B is replaceable. By selecting materials with different physical properties to replace the original marble module, the stiffness characteristics and strain measurement sensitivity of the entire device can be adjusted, adapting to different testing requirements and application scenarios. Module B is a rectangle with a length of 17mm, a width of 14mm, and a height of 5mm, located between Module A and Module C (e.g., ...). Figure 1(As shown). The elastic modulus of module B is similar to that of the object being measured, in order to adapt to the measurement requirements of different objects.

[0039] The following experiments and data further demonstrate this:

[0040] (1) Selection of materials and data:

[0041] Module A (Module C): Q420 metal block with an elastic modulus of 210 GPa;

[0042] Module B and the object under test: C50 concrete block with an elastic modulus of 34.5 GPa;

[0043] Load capacity: 10000KN

[0044] A simplified diagram of the experimental model is shown below. Figure 5 As shown, the experimental data are as follows: Figure 4 As shown.

[0045] (2) Calculation process

[0046] The formula relating strain and elastic modulus is as follows:

[0047]

[0048] Subscript 1 represents the physical quantity of the object being measured, subscript 2 represents the physical quantity of the iron block, and subscript 3 represents the physical quantity of the strain gauge metal block.

[0049] Basic formula:

[0050]

[0051] Value:

[0052] Elastic modulus: E1 = E3 = 35 GPa, E2 = 210 GPa

[0053] Length measurement: L1 = L2 = L3

[0054] Cross-sectional ratio: S1:S2:S3=(1*1):(0.1*0.1):(0.1*0.05)=200:2:1

[0055] Detailed steps:

[0056] First, the local elongation of the object being measured is the same as that of the iron block. Substitute the data into the formula above.

[0057] Determine the relationship between the axial forces of the measured object and the iron block:

[0058] Since ΔL1 = ΔL2, we get:

[0059]

[0060] In the formula, the measured length L, elastic modulus E, and area S are all known. Substituting these values ​​into the formula, we obtain: F1:F2 = 16.7:1

[0061] Based on the measured data, the ratio of the elongation of the tested object to that of the strain gauge metal block under compression is:

[0062] ΔL2:ΔL3 = 1:1.7;

[0063] Therefore, ΔL3 = 1.7 × ΔL2, which gives:

[0064]

[0065] Given the measured length L, elastic modulus E, and area S, substituting them into the formula yields: F2:F3 = 7:1

[0066] In summary, the axial force ratio of the three observed objects—the measured object, the iron block, and the strain gauge metal block—can be obtained as follows: F1:F2:F3=(16.7*7):7:1=116.9:7:1

[0067] The elongation ratio is: ΔL1:ΔL2:ΔL3 = 0.140:0.238 = 1:1:1.7

[0068] (3) Conclusion

[0069] Under specific axial pressure, the strain gauge metal block is designed to sensitively reflect the strain changes of the measured object with a high magnification ratio.

[0070] Under constant axial force, the strain amplification ratio can be effectively increased by adjusting the elastic modulus and cross-sectional area of ​​the strain gauge. Specifically, the smaller the product of the elastic modulus (E) and the cross-sectional area (S) of the strain gauge metal block, the more significant the strain amplification effect. This design principle enables the strain gauge to respond to minute deformations of the measured object with higher sensitivity, thereby achieving accurate strain measurement and analysis. The performance of the strain gauge can be significantly improved through careful material selection and optimized geometry.

[0071] Therefore, the embodiments of the present invention have significant differences compared with the embodiments of the prior art:

[0072] (1) Existing technology involves the direct pasting of pre-made strain gauges, which results in a small measurement range and is susceptible to accidental factors, leading to insufficient accuracy. This invention pastes the strain gauges onto a material with low stiffness, and then adheres this material to the center of a high-stiffness iron block to form a strain gauge amplifier.

[0073] (2) When strain gauges are attached to the surface of the object being measured, careful design can concentrate the strain in a specific region with low stiffness. This design strategy amplifies the strain values ​​measured by the strain gauges, thereby significantly improving measurement accuracy. In this way, strain gauges can more sensitively capture minute deformations, making previously indistinguishable minute strain changes measurable, thus enhancing the performance of the entire measurement system. This method is particularly suitable for applications requiring high sensitivity and high precision measurements, such as materials testing, structural health monitoring, and precision engineering.

[0074] Compared with related technologies, the strain gauge device provided by this invention, which improves the sensitivity and accuracy of strain measurement, has the following beneficial effects:

[0075] (1) In the process of designing and manufacturing the device, the selection of materials for the intermediate parts is a crucial step, which directly affects the performance, reliability and cost-effectiveness of the device. By carefully selecting and replacing the materials for the intermediate parts, the versatility and functionality of the device can be achieved, meeting the needs of different application scenarios.

[0076] (2) Strain measurement is a key technology used to monitor and analyze the deformation of structures under stress. Strain gauges, as sensors that convert mechanical strain into electrical signals, play a crucial role in this process. By replacing only the strain gauge patches, rapid adaptation to different measurement needs can be achieved without replacing the entire measuring device, thus significantly improving the device's lifespan and flexibility. This method is becoming increasingly important in modern measurement technology, providing engineers and researchers with a cost-effective solution.

[0077] (3) Improved sensitivity and accuracy of strain measurement: Due to the strain concentration in the central region, even minute strains can be effectively detected and amplified. This allows strain gauges to respond to minute deformations, providing crucial data for analyzing and predicting the mechanical behavior of materials. Furthermore, it can provide more precise data, which is essential for understanding the mechanical properties of materials and predicting their performance in practical applications. This high-precision measurement capability, especially in the design and monitoring of critical structures and equipment, can significantly improve safety and reliability.

[0078] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A strain gauge device that can improve the sensitivity and accuracy of strain measurement, characterized in that, The device consists of three modules, A, B, and C, stacked vertically. composition: Module B is located in the middle and is the core of the structure. It is used to directly contact the object being tested. Module B is an intermediate material with a low elastic modulus. Module A and Module C are located on both sides and are symmetrically arranged. The size of Module C is the same as that of Module A to ensure the balance and uniform force distribution of the device during use. The strain gauge is attached to module B. The strain gauge and the low elastic modulus of module B are combined to improve the sensitivity and accuracy of strain measurement by contrasting the high stiffness of modules A and C. The material of module B is replaceable. By selecting materials with different physical properties, the stiffness characteristics and strain measurement sensitivity of the entire device can be adjusted to adapt to different testing requirements and application scenarios. Both Module A and Module C are precision-machined from a single rectangular block of sturdy and durable stainless steel, ensuring the stability and strength of the overall structure. The original dimensions of modules A and C are 27mm in length, 14mm in width, and 12mm in height. A rectangular area with internal dimensions of 17mm in length and 3mm in height is cut out to form the unique geometry of modules A and C. This reduces the influence of lateral strain on the measurement results and enhances the strain gauge's ability to detect minute deformations. Module B is a rectangle with a length of 17mm, a width of 14mm, and a height of 5mm, located between modules A and C.

2. The strain gauge device as described in claim 1, which improves the sensitivity and accuracy of strain measurement, is characterized in that... The elastic modulus of module B is similar to that of the object being measured, so as to adapt to the measurement requirements of different objects being measured.

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