Strain gauge device capable of improving sensitivity and precision of strain measurement

Abstract

The invention relates to the technical field of sensors, and discloses a strain gauge device capable of improving the sensitivity and precision of strain measurement. The strain gauge device capable of improving the sensitivity and precision of strain measurement is formed by vertically stacking a module A, a module B and a module C. The module B is located in the middle, is the core of the structure and is used for directly making contact with a measured object, and the module B is an intermediate material with the low elastic modulus. The module A and the module C are located on the two sides and are symmetrically arranged, and the size of the module C is the same as that of the module A. According to the strain gauge device capable of improving the sensitivity and precision of strain measurement, through the overhead iron block technology, the transverse strain influence is reduced, the resistance change detection capacity is enhanced, errors caused by surface unevenness are reduced, and the high measurement sensitivity is kept; through a replaceable intermediate material technology, the strain gauge can be recycled, and the cost and the resource consumption are reduced.

Description

Technical Field

[0001] The present invention relates to the field of sensor technology, and in particular to a strain gauge device capable of improving the sensitivity and accuracy of strain measurement. Background Art

[0002] As an important part of modern sensing technology, strain gauges are widely used in many fields such as industrial automation, aerospace, civil engineering, etc. to accurately measure the deformation of objects under force. As the core component of modern sensing technology, the core function of strain gauges is to accurately convert the tiny deformation of objects under force into quantifiable electrical signals, thereby realizing 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, that is, when a conductor or semiconductor material is mechanically deformed under the action of external forces, its resistance value will change accordingly. This phenomenon is called "strain effect", while the working principle of semiconductor strain gauges is based on the "piezoresistive effect", that is, when a semiconductor material is subjected to force in a certain axial direction, its resistivity changes.

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

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

[0006]

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

[0008] However, in a large strain environment, the accuracy of the strain gauge will be affected by key factors such as material nonlinearity, lateral effects, temperature effects, mechanical hysteresis and creep, installation and bonding problems, and dynamic response limitations. This is because: the strain gauge may be affected by the lateral strain in large strain measurements, resulting in resistance changes that do not fully reflect the axial strain and produce measurement deviations. At the same time, due to material nonlinearity, such as plastic deformation or damage, the measurement results of the strain gauge based on linear design will be inaccurate, especially in high strain areas.

[0009] In addition, the measurement accuracy of the strain gauge may be affected by the surface structure of the object being measured. Because the working principle of the strain gauge is based on the change of resistance, this change is directly related to the deformation of the surface of the object. Surface roughness and curvature have a significant impact on the measurement accuracy of the strain gauge. Excessive roughness may cause uneven contact between the strain gauge and the measuring surface, unstable adhesion, and introduce 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 is more likely to 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, resulting in degradation of their performance and thus making them impossible to reuse. Existing strain gauges are usually considered disposable devices, mainly because once they are glued to the surface of the measured object using a specific glue, it is difficult to remove them without damaging the sensitive grid. Damage to the sensitive grid will directly affect the measurement capability of the strain gauge, and even if there is no damage, the strain gauge cannot guarantee the original precise position and direction after being disassembled and then glued, which may lead 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 technical problems. Summary of the invention

[0012] In order to solve the technical problems of limited sensitivity, poor environmental adaptability and high resource consumption (such as non-reusability) commonly found in traditional strain gauges, the present invention provides a strain gauge device that can improve the sensitivity and accuracy of strain measurement, and aims to fundamentally solve the above problems by introducing innovative overhead iron block technology and replaceable intermediate material technology. This design not only greatly improves the measurement accuracy and sensitivity of the strain gauge, ensuring the accuracy and reliability of the measurement data, but also realizes the convenient replacement of intermediate materials through modular design, significantly enhancing the environmental adaptability and reusability of the strain gauge, and reducing long-term operation and maintenance costs.

[0013] The strain gauge device provided by the present invention can improve the sensitivity and accuracy of strain measurement, and is composed of three modules, namely module A, module B and module C, which are stacked vertically: wherein module B is located in the middle and is the core of the structure, and is used to directly contact the object to be measured, and 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, and the size of module C is the same as that of module A, so as to ensure the balance and uniform stress of the device during use; the strain gauge is pasted on the module B, and the strain gauge is combined with the low elastic modulus characteristics of the module B, and the sensitivity and accuracy of strain measurement are significantly improved through the high stiffness comparison between module A and module C.

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

[0015] Preferably, the module A and the module C are both made of a rectangular solid and durable stainless steel block, which ensures the stability and strength of the overall structure.

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

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

[0018] Preferably, the elastic modulus of the module B is similar to that of the object to be measured to meet the measurement requirements of different objects to be measured.

[0019] Compared with the related art, the strain gauge device provided by the present invention which can improve the sensitivity and accuracy of strain measurement has the following beneficial effects:

[0020] 1. In view of the shortcomings of the existing technology that the accuracy decreases within a large strain range, the present invention adopts an innovative overhead iron block technology, which effectively reduces the impact of lateral strain on the measurement results and reduces the interference of nonlinear characteristics of materials in high strain areas. This technology significantly improves the measurement accuracy by significantly enhancing the detection capability of small changes in resistance. This sophisticated measurement method not only improves the reliability of experimental results, but also ensures the accuracy of data, providing solid data support for engineering and scientific research.

[0021] 2. In view of the shortcoming of being easily affected by the surface structure of the measured object, the present invention effectively avoids the problem of reduced sensitivity of strain gauges caused by the roughness and curvature of the surface of the object by cleverly applying the overhead iron block technology to contact the measured object. This technology reduces the error caused by surface unevenness by reducing the contact points. At the same time, the overhead design also reduces the uneven stress distribution caused by surface curvature, thereby ensuring the high sensitivity of the measurement process and the accuracy of the data. In addition, the application of the overhead iron block can also reduce the measurement deviation caused by uneven contact surface pressure, further improving the reliability and accuracy of the measurement results.

[0022] 3. In view of the shortcoming of strain gauges in the prior art that they cannot be reused, the present invention adopts innovative replaceable intermediate material technology to successfully realize the recycling of strain gauges and avoid damage to the performance of strain gauges. Traditionally, once a strain gauge is pasted and used, it is difficult to remove it from the surface of the measured object without loss. Even if the removal is successful, it is difficult to ensure that the re-pasted strain gauge is consistent with the position and direction when it was first used, thus affecting the accuracy of the measurement results. This technology realizes the recycling of strain gauges through intermediate materials, reduces costs and resource consumption, and ensures the accuracy of measurement, meeting the requirements of sustainable development. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

[0026] Figure 4 It is the experimental data diagram of the present invention;

[0027] Figure 5 It is a schematic 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 It is a three-dimensional sample diagram of the component of the present invention. DETAILED DESCRIPTION

[0030] First, the present invention describes the design principle of the scheme:

[0031] When two materials with very different stiffnesses are combined to form a composite material, we can usually expect the less stiff material to take on more deformation. This is because the less stiff material will experience a greater strain and exhibit a greater deformation when subjected to the same external force.

[0032] The stiffness distribution of this specially designed strain gauge is designed to form a structure with lower stiffness in the middle area and higher stiffness in the two end areas. This design allows the strain gauge to produce a larger deformation in the middle area due to the lower stiffness when subjected to external force, while the deformation is smaller in the two end areas due to the higher stiffness. Such a stiffness difference causes the strain to be concentrated in the middle area, so that the resistance change of the strain gauge mainly reflects the strain state in the middle area.

[0033] The key advantage of this design is that it can improve the sensitivity and accuracy of strain measurement. Due to the concentrated strain in the middle area, even the smaller strain can be effectively detected and amplified, allowing the strain gauge to respond to such small strains that are difficult to detect. In addition, this design also helps to reduce measurement errors caused by structural complexity or areas where it is difficult to directly measure strain.

[0034] (In practical applications, this strain gauge can be pasted on the key areas of the object to be measured, and its high sensitivity can be used to accurately measure local strain. The design of this strain gauge is particularly suitable for application scenarios such as monitoring local strain concentration or material fatigue, providing engineers with a powerful tool to ensure the safety and reliability of the structure.)

[0035] The device of the present invention is further described below in conjunction with the accompanying drawings and embodiments.

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

[0037] Module A and module C are located on both sides and are symmetrically arranged. The structure and size of module C are the same as those of module A, ensuring the balance and uniform force of the device during use; both modules A and C are finely processed from a rectangular solid and durable stainless steel block material, ensuring the stability and strength of the overall structure; the original dimensions of modules A and C are 27 mm in length, 14 mm in width, and 12 mm in height, and a rectangular area with an inner dimension of 17 mm in length and 3 mm in height is cut off, thereby forming a unique geometric shape of modules A and C (such as Figure 1 This unique geometric design effectively reduces the impact of lateral strain on the measurement results, while enhancing the strain gauge's ability to detect tiny deformations.

[0038] Module B is located in the middle and is the core of the structure. It is used to directly contact the object to be measured. Module B is an intermediate material with a low elastic modulus. The strain gauge is pasted on the module B. The strain gauge is combined with the low elastic modulus characteristics of the module B. Through the high stiffness comparison between module A and module C, the sensitivity and accuracy of strain measurement are significantly improved. The material of module B is replaceable. By selecting materials with different physical properties to replace the original marble module, the stiffness characteristics of the entire device and the sensitivity of strain measurement can be adjusted to adapt to different test requirements and application scenarios. Module B is a rectangle with a length of 17mm, a width of 14mm, and a height of 5mm. It is located between module A and module C (such as Figure 1The elastic modulus of module B is similar to that of the object to be measured, so as to meet the measurement requirements of different objects to be measured.

[0039] The following experiments and data further prove that:

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

[0041] Module A (module C): Q420 metal block, elastic modulus is 210Gpa;

[0042] Module B and the object under test: C50 concrete block, elastic modulus 34.5Gpa;

[0043] Load size: 10000KN

[0044] The experimental model is shown in the figure Figure 5 As shown in Figure 4 shown.

[0045] (2) Calculation process

[0046] The relationship between strain and elastic modulus is:

[0047]

[0048] The subscript 1 is the physical quantity of the object being measured, the subscript 2 is the physical quantity of the iron block, and the subscript 3 is 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] Measuring length: 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 above formula:

[0057] Obtain the axial force relationship between the object being measured and the iron block:

[0058] Because ΔL1=ΔL2, we have:

[0059]

[0060] In the formula, the measured length L, elastic modulus E and area S are all known, and we can get: F1:F2=16.7:1

[0061] According to the measured data, the ratio of the elongation of the measured object and the strain gauge metal block under pressure is:

[0062] ΔL2:ΔL3=1:1.7;

[0063] So ΔL3=1.7×ΔL2, we can get:

[0064]

[0065] The measured length L, elastic modulus E and area S are all known, and we can substitute them into the formula to obtain: F2:F3=7:1

[0066] In summary, the axial force ratio of the three observation objects, the object being measured, the iron block and the strain gauge metal block, is: F1:F2:F3=(16.7*7):7:1=116.9:7:1

[0067] At the same time, the elongation ratio is: ΔL1:ΔL2:ΔL3=0.140:0.238=1:1:1.7

[0068] (3) Conclusion

[0069] Under a specific axial pressure, the metal block of the strain gauge is designed to sensitively reflect the strain changes of the object being measured with a high amplification 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 tiny deformations of the measured object with higher sensitivity, thereby achieving accurate measurement and analysis of strain. The performance of the strain gauge can be significantly improved by carefully selecting materials and optimizing geometric dimensions.

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

[0072] (1) The prior art is to directly paste the finished strain gauge, which has a small measurement range and is easily affected by accidental factors, resulting in insufficient accuracy. The present invention pastes the strain gauge on a material with low rigidity, and then adheres the material to the center of a large rigidity iron block to form a strain gauge amplifier.

[0073] (2) When the strain gauge is attached to the surface of the object to be measured, through careful design, the strain can be concentrated in a specific area with less stiffness. This design strategy can achieve the amplification effect of the strain value measured by the strain gauge, thereby significantly improving the measurement accuracy. In this way, the strain gauge can more sensitively capture tiny deformations, making the originally difficult to distinguish tiny strain changes measurable, thereby enhancing the performance of the entire measurement system. This method is particularly suitable for application scenarios that require high sensitivity and high-precision measurements, such as material testing, structural health monitoring, and precision engineering.

[0074] Compared with the related art, the strain gauge device provided by the present invention which can improve the sensitivity and accuracy of strain measurement has the following beneficial effects:

[0075] (1) In the process of designing and manufacturing the device, the material selection of the middle part is a crucial link, which directly affects the performance, reliability and cost-effectiveness of the device. By carefully selecting and replacing the materials of the middle part, the diversity and functionality of the device can be achieved to meet the needs of different application scenarios.

[0076] (2) Strain measurement is a key technology used to monitor and analyze the deformation of structures when they are subjected to stress. Strain gauges, as sensors that convert mechanical strain into electrical signals, play a vital role in this process. By replacing only the strain gauge patch, it is possible to quickly adapt to different measurement needs without replacing the entire measurement device, thereby significantly improving the service life and flexibility of the device. This method is becoming increasingly important in modern measurement technology and provides engineers and researchers with a cost-effective solution.

[0077] (3) Improve the sensitivity and accuracy of strain measurement: Due to the strain concentration in the middle area, even small strains can be effectively detected and amplified, which enables the strain gauge to respond to small deformations, thereby providing important data for analyzing and predicting the mechanical behavior of materials. And it can provide more accurate data, which is crucial for understanding the mechanical properties of materials and predicting their performance in practical applications. This high-precision measurement capability can significantly improve safety and reliability, especially in the design and monitoring of critical structures and equipment.

[0078] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A strain gauge device capable of improving the sensitivity and accuracy of strain measurement, It is characterized in that The device consists of three modules, module A, module B and module C, which are stacked vertically. composition: Among them, module B is located in the middle and is the core of the structure. It is used to directly contact the object to be measured. 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 of the device during use; The strain gauge is attached to the module B. The strain gauge is combined with the low elastic modulus characteristic of the module B, and the sensitivity and accuracy of strain measurement are improved by comparing the high stiffness of the modules A and C.

2. The strain gauge device capable of improving the sensitivity and accuracy of strain measurement as claimed in claim 1, It is characterized in that The material of the module B is replaceable. By selecting materials with different physical properties, the stiffness characteristics of the entire device and the sensitivity of strain measurement can be adjusted to achieve adaptation to different test requirements and application scenarios.

3. The strain gauge device capable of improving the sensitivity and accuracy of strain measurement as claimed in claim 1, It is characterized in that The module A and the module C are both made of a rectangular solid and durable stainless steel block, which ensures the stability and strength of the overall structure.

4. The strain gauge device capable of improving the sensitivity and accuracy of strain measurement as claimed in claim 1, It is characterized in that The original dimensions of the modules A and C are 27 mm in length, 14 mm in width, and 12 mm in height, and a rectangular area with an inner dimension of 17 mm in length and 3 mm in height is cut off, thereby forming a unique geometric shape of the modules A and C, which is used to reduce the influence of the lateral strain on the measurement results and enhance the strain gauge's ability to detect small deformations.

5. The strain gauge device capable of improving the sensitivity and accuracy of strain measurement as claimed in claim 1, It is characterized in that The module B is a rectangle with a length of 17 mm, a width of 14 mm, and a height of 5 mm, and is located between the modules A and C.

6. The strain gauge device capable of improving the sensitivity and accuracy of strain measurement as claimed in claim 1, It is characterized in that The elastic modulus of the module B is similar to that of the object to be measured, so as to meet the measurement requirements of different objects to be measured.

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