A hollow inclusion stress sensor indoor non-destructive calibration device and a method of using the same
Patent Information
- Application Number
- CN202611155627.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-07-31
- Publication Date
- 2026-10-13
AI Technical Summary
该类方法虽可实现一定程度的标定，但传感器与试件之间通常形成较强粘结，试验完成后难以无损拆除，导致传感器无法继续用于后续工程测试，通常只能进行抽样标定，难以实现对实际使用传感器的逐支校核
本发明提供了一种空心包体应力传感器室内无损标定装置，该空心包体应力传感器室内无损标定装置包括一种标定单体或通过二种及以上标定单体串联组装得到，使可同时进行多个空心包体应力传感器的标定；标定单体包括底座、固定组件、支撑架和围压室；底座上开设有两个底座固定孔，用于固定底座；空心包体应力传感器沿着围压室的轴向方向贯穿围压室设置，使空心包体应力传感器在围压室内受压均匀，空心包体应力传感器的两端位于围压室外部，使安装时方便空心包体应力传感器的轴线与围压室的轴线对正，同时空心包体应力传感器与围压室可拆卸连接，使实现对空心包体应力传感器无损标定，且空心包体应力传感器标定完成后可继续正常使用；固定组件的中部开设有容置空间，围压室的两端位于容置空间内，容置空间与围压室的两端相适配，使得围压室的轴线与容置空间的中心线对正，即使得空心包体应力传感器的轴线与容置空间的中心线对正，避免标定时因空心包体应力传感器的起始变形造成标定误差；固定组件通过支撑架与底座活动连接，支撑架可沿空心包体应力传感器的轴向方向倾斜，使固定组件能够沿空心包体应力传感器的轴向方向发生自由微位移，从而减小空心包体应力传感器两侧的固定组件对空心包体应力传感器轴向变形的约束作用，使空心包体应力传感器在围压加载条件下的实际变形状态更接近厚壁圆筒受均匀围压作用时的理论状态；综上，本发明提供了一种空心包体应力传感器室内无损标定装置，可实现对空心包体应力传感器的无损标定，且标定完成后的空心包体应力传感器可正常使用。
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Figure CN122900760A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of geotechnical engineering stress testing, and in particular to an indoor non-destructive calibration device for a hollow-encapsulated stress sensor and its usage method. Background Technology
[0002] Hollow inclusion stress sensors are widely used in initial stress testing and disturbance stress monitoring of rock masses because they can determine the three-dimensional stress state of the rock mass through a single measurement. These sensors typically have multiple strain gauges arranged along a specific orientation on the outer surface or inner wall of the inclusion. Stress components are deduced by measuring strain in different directions and combining this with a solution model. Due to factors such as strain gauge placement, orientation angle, manufacturing and assembly errors, and individual sensor variations, there is often a deviation between the actual output characteristics and the theoretical design values. Therefore, calibration is essential before deployment to establish an accurate correspondence between strain response and external load, thereby improving testing accuracy and result reliability.
[0003] In existing technologies, indoor calibration of hollow-encased stress sensors often employs adhesive bonding, where the sensor is pre-embedded or bonded to a cubic concrete specimen, and the strain-response relationship is obtained through external loading. While this method achieves a certain degree of calibration, a strong bond typically forms between the sensor and the specimen, making non-destructive removal difficult after testing. This renders the sensor unusable for subsequent engineering tests, typically limiting calibration to sampling rather than individual verification of each sensor in actual use. Furthermore, the properties of the bonding materials and differences in interfacial force transfer can have additional impacts on the calibration results.
[0004] Therefore, how to provide an indoor non-destructive calibration device for hollow-body stress sensors that can achieve the technical effect of non-destructive calibration without the need for bonding and fixing is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention
[0005] In view of the problems existing in the prior art, the technical problem to be solved by the present invention is to provide an indoor non-destructive calibration device for a hollow body stress sensor, which can achieve the technical effect of non-destructive calibration without the need for bonding and fixing.
[0006] To achieve the above objectives, the present invention provides an indoor non-destructive calibration device for a hollow inclusion stress sensor. This device is assembled from at least one calibration unit, which includes: a base parallel to a horizontal surface; two fixing components located on the upper surface of the base and arranged parallel to each other; a receiving space in the middle of each fixing component; two sets of support frames corresponding to the two fixing components, each fixing component being movably connected to the base via a corresponding set of support frames; and a confining pressure chamber through which the hollow inclusion stress sensor penetrates along the axial direction of the confining pressure chamber; one end of the confining pressure chamber is located within one of the receiving spaces, and the other end is located within the other receiving space.
[0007] In the first aspect, each of the fixing components includes: a lower half-ring clamp, the upper middle part of which has a concave semi-arc structure; the lower part of the lower half-ring clamp is movably connected to the base via a corresponding set of support frames; an upper half-ring clamp, the lower middle part of which has an upward concave semi-arc structure; the upper half-ring clamp is located above the lower half-ring clamp and together with the lower half-ring clamp forms the accommodating space; the upper half-ring clamp and the lower half-ring clamp are detachably connected; wherein, both ends of the confining chamber abut against the corresponding lower half-ring clamp and the corresponding upper half-ring clamp.
[0008] In the first aspect, the confining pressure chamber includes: a confining pressure cavity, the confining pressure cavity having a cylindrical structure, and a hollow-body stress sensor disposed through the confining pressure cavity along the axial direction of the confining pressure cavity; one end of the confining pressure cavity is located in one of the accommodating spaces, and the other end of the confining pressure cavity is located in another of the accommodating spaces; wherein both ends of the confining pressure cavity abut against the lower half of the ring clamp and the upper half of the ring clamp; a pressure outlet is provided on the confining pressure cavity, the pressure outlet being connected to a hydraulic loading system; and a pressure sensor is disposed inside the pressure outlet.
[0009] In the first aspect, the confining pressure chamber further includes: two pressure caps, each pressure cap having a circular ring structure; one pressure cap being sleeved around one end of the hollow infill stress sensor and detachably connected to the confining pressure chamber; and the other pressure cap being sleeved around the other end of the hollow infill stress sensor and detachably connected to the confining pressure chamber; two circular washers, each circular washer having a circular ring structure; one circular washer being sleeved around one end of the hollow infill stress sensor; and the other circular washer being sleeved around the other end of the hollow infill stress sensor; any one of the circular washers is located between the pressure cap and the hollow infill stress sensor, and abuts against both the pressure cap and the hollow infill stress sensor respectively.
[0010] In the first aspect, the upper surface of the base is provided with two sets of support grooves, and the two sets of support grooves are arranged one-to-one with the two sets of support frames; each set of support grooves includes two square grooves; wherein, each set of support frames includes two movable supports, and the two movable supports are respectively located at the lower ends of a corresponding lower half ring clamp; each square groove is adapted to a corresponding movable support; one end of each movable support is detachably connected to the lower half ring clamp, and the other end of each movable support is located in a corresponding square groove and is movably connected to the base, so that the lower half ring clamp can freely micro-displace along the axial direction of the hollow package stress sensor.
[0011] In the first aspect, the indoor non-destructive calibration device for the hollow inclusion stress sensor includes one calibration unit; one end of the hollow inclusion stress sensor has a stress data acquisition line outlet, and the hollow inclusion stress sensor is connected to an external data acquisition system via a first stress data acquisition line; the stress data acquisition line outlet is for the first stress data acquisition line to pass through; or, the indoor non-destructive calibration device for the hollow inclusion stress sensor includes at least two calibration units, each of the hollow inclusion stress sensors having a stress data acquisition line outlet at one end; any two adjacent hollow inclusion stress sensors are connected in series via a second data acquisition line, and the two hollow inclusion stress sensors located at both ends of the series connection are respectively connected to an external data acquisition system via a third data acquisition line; each of the second data acquisition line and each of the third data acquisition lines passes through the corresponding stress data acquisition line outlet.
[0012] This invention also provides a method for using an indoor non-destructive calibration device for a hollow inclusion stress sensor, used in the aforementioned indoor non-destructive calibration device for a hollow inclusion stress sensor. The method includes: assembling the hollow inclusion stress sensor to be calibrated in the corresponding calibration unit, aligning the axis of the hollow inclusion stress sensor with the center line connecting the two corresponding accommodating spaces to complete calibration preparation; gradually applying confining pressure to the confining pressure chamber using a hydraulic loading system in a graded loading manner, maintaining pressure stability under each level of confining pressure, and synchronously acquiring the output data of each strain measurement channel of the hollow inclusion stress sensor through an external data acquisition system, establishing a correlation between the measured strain of each strain measurement channel of the hollow inclusion stress sensor and the confining pressure. Correspondence: Based on the theory of thick-walled cylinders under uniform confining pressure, the relationship between the theoretical strain and confining pressure of each strain measurement channel of the hollow inclusion stress sensor is established, and the theoretical slope coefficients corresponding to each strain measurement channel of the hollow inclusion stress sensor are obtained; the measured strain and confining pressure data of each strain measurement channel of the hollow inclusion stress sensor are linearly fitted to obtain the experimental fitting slope corresponding to each strain measurement channel of the hollow inclusion stress sensor; based on the theoretical slope coefficients and experimental fitting slopes, the calibration coefficients of the hollow inclusion stress sensor are obtained, and the measured strain of each strain measurement channel of the hollow inclusion stress sensor is corrected using the calibration coefficients; the calibrated hollow inclusion stress sensor is then taken out.
[0013] In the second aspect, the theoretical strain of any strain measurement channel of the hollow inclusion stress sensor for: ; wherein, the φ i The angle between the i-th strain measurement channel and the axis of the hollow inclusion stress sensor; the The axial strain is the inner surface of the hollow-body stress sensor. The internal pressure is 0; The circumferential strain is the inner surface of the hollow inclusion stress sensor. The internal pressure is 0; 'a' is the inner radius of the hollow cylinder of the hollow cavity stress sensor; 'R' is... s The hollow cylinder of the hollow inclusion stress sensor has an outer radius of 1; E2 is the elastic modulus; v2 is Poisson's ratio; p is the confining pressure; based on The theoretical strain of any strain measurement channel of the hollow inclusion stress sensor satisfies a linear relationship with the confining pressure: ; wherein, the For the theoretical strain of the i-th channel, the is the slope coefficient of the theoretical strain versus confining pressure relationship for the i-th channel.
[0014] In the second aspect, the linear fitting formula between the measured strain and the confining pressure of any strain measurement channel of the hollow inclusion stress sensor is as follows: ; wherein, the For the measured strain of the i-th channel, the Let b be the slope of the fitted test for the i-th channel. i This is the fitting intercept.
[0015] In the second aspect, the fitting intercept Ignoring the timing, the calibration coefficient for: .
[0016] Beneficial effects This invention provides an indoor non-destructive calibration device for hollow infill stress sensors. The device comprises a single calibration unit or is assembled from two or more calibration units in series, enabling simultaneous calibration of multiple hollow infill stress sensors. Each calibration unit includes a base, a fixing component, a support frame, and a confining pressure chamber. The base has two fixing holes for securing the base. The hollow infill stress sensor is positioned along the axial direction of the confining pressure chamber, ensuring uniform pressure distribution within the chamber. Both ends of the sensor are located outside the chamber, facilitating alignment of the sensor's axis with the chamber's axis during installation. The sensor is detachably connected to the chamber, enabling non-destructive calibration of the hollow infill stress sensor, which can then continue to be used normally after calibration. The fixing component has a central accommodating space, with both ends of the confining pressure chamber located within the accommodating space. Within the space, the two ends of the accommodating space and the confining pressure chamber are adapted to align the axis of the confining pressure chamber with the centerline of the accommodating space, thus ensuring that the axis of the hollow infill stress sensor is aligned with the centerline of the accommodating space. This avoids calibration errors caused by the initial deformation of the hollow infill stress sensor during calibration. The fixing component is movably connected to the base via a support frame, which can tilt along the axial direction of the hollow infill stress sensor. This allows the fixing component to undergo free micro-displacement along the axial direction of the hollow infill stress sensor, thereby reducing the constraint effect of the fixing components on the axial deformation of the hollow infill stress sensor. This makes the actual deformation state of the hollow infill stress sensor under confining pressure loading conditions closer to the theoretical state of a thick-walled cylinder under uniform confining pressure. In summary, this invention provides an indoor non-destructive calibration device for hollow infill stress sensors, enabling non-destructive calibration of hollow infill stress sensors, and the calibrated hollow infill stress sensors can be used normally. Attached Figure Description
[0017] To more clearly illustrate the technical solutions in the embodiments of this specification or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0018] Figure 1 This is a schematic diagram of the structure of an indoor non-destructive calibration device for a hollow-body stress sensor according to the present invention.
[0019] Figure 2 yes Figure 1 The front view.
[0020] Figure 3 This is a plan view of the base of the present invention.
[0021] Figure 4 yes Figure 3 AA interface cross-section diagram.
[0022] Figure label: 1. Base; 2. Fixing assembly; 21. Lower half of the ring clamp; 22. Upper half of the ring clamp; 3. Confining pressure chamber; 31. Confining pressure cavity; 32. Pressure cover; 33. Circular gasket; 4. Hollow Inclusion Stress Sensor; 5. Movable support frame; 101. Pressure inlet; 102. Square groove; 103. Stress data acquisition line outlet; 104. Base fixing hole. Detailed Implementation
[0023] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.
[0024] Example 1 like Figures 1-4As shown, the present invention provides an indoor non-destructive calibration device for a hollow infill stress sensor. The device is assembled from at least one calibration unit, which includes: a base 1 parallel to a horizontal surface; two fixing components 2 located on the upper surface of the base 1 and arranged parallel to each other; a receiving space in the middle of each fixing component 2; two sets of support frames corresponding to the two fixing components 2, each fixing component 2 being movably connected to the base 1 via a corresponding set of support frames 3; and a confining pressure chamber 3 through which a hollow infill stress sensor 4 penetrates along the axial direction of the confining pressure chamber 3; one end of the confining pressure chamber 3 is located within one receiving space, and the other end is located within the other receiving space.
[0025] This invention provides an indoor non-destructive calibration device for hollow infill stress sensors. The device comprises a single calibration unit or is assembled from two or more calibration units in series, enabling simultaneous calibration of multiple hollow infill stress sensors. Each calibration unit includes a base, a fixing component, a support frame, and a confining pressure chamber. The base has two base fixing holes 104 for fixing the base. The hollow infill stress sensor is installed through the confining pressure chamber along its axial direction, ensuring uniform pressure distribution within the chamber. Both ends of the sensor are located outside the chamber, facilitating alignment of the sensor's axis with the chamber's axis during installation. The sensor is detachably connected to the chamber, enabling non-destructive calibration of the hollow infill stress sensor, which can then continue to be used normally after calibration. The fixing component has a accommodating space in its middle, with both ends of the confining pressure chamber located within the accommodating space. Within the accommodating space, the two ends of the accommodating space and the confining pressure chamber are adapted to align the axis of the confining pressure chamber with the centerline of the accommodating space. This ensures that the axis of the hollow infill stress sensor is aligned with the centerline of the accommodating space, avoiding calibration errors caused by the initial deformation of the hollow infill stress sensor during calibration. The fixing component is movably connected to the base via a support frame. The support frame can tilt along the axial direction of the hollow infill stress sensor, allowing the fixing component to undergo free micro-displacement along the axial direction of the hollow infill stress sensor. This reduces the constraint effect of the fixing components on the axial deformation of the hollow infill stress sensor, making the actual deformation state of the hollow infill stress sensor under confining pressure loading conditions closer to the theoretical state of a thick-walled cylinder under uniform confining pressure. In summary, this invention provides an indoor non-destructive calibration device for hollow infill stress sensors, enabling non-destructive calibration of hollow infill stress sensors, and the calibrated hollow infill stress sensors can be used normally.
[0026] In one possible implementation, each of the fixing components 2 includes: a lower half-ring clamp 21, the upper middle part of which has a concave semi-arc structure; the lower part of the lower half-ring clamp 21 is movably connected to the base 1 via a corresponding set of support frames; an upper half-ring clamp 22, the lower middle part of which has an upward concave semi-arc structure; the upper half-ring clamp 22 is located above the lower half-ring clamp 22 and together with the lower half-ring clamp 21 forms the accommodating space; the upper half-ring clamp 22 and the lower half-ring clamp 21 are detachably connected; wherein, both ends of the confining pressure chamber 3 abut against the corresponding lower half-ring clamp 21 and the corresponding upper half-ring clamp 22.
[0027] Specifically, the lower half of the ring clamp has a semi-arc structure at the upper middle part and the upper half of the ring clamp at the lower middle part. This semi-arc structure has an arc-shaped support surface that matches the outer contour of both ends of the confining pressure chamber, which can improve the coaxiality of the hollow cavity stress sensor installation and the uniformity of radial force. The lower half of the ring clamp and the upper half of the ring clamp together form an accommodating space, which matches the shape of both ends of the confining pressure chamber. The lower half of the ring clamp and the upper half of the ring clamp are connected by bolts to form a detachable clamping structure. While positioning, supporting and clamping the confining pressure chamber, it also achieves the technical effect of positioning and supporting the hollow cavity stress sensor. The lower half of the ring clamp is movably connected to the base through a support frame, allowing the lower half of the ring clamp and the upper half of the ring clamp to move freely in the axial direction of the hollow cavity stress sensor, thereby reducing the constraint effect on the axial deformation of the hollow cavity stress sensor.
[0028] In one possible implementation, the confining pressure chamber 3 includes: a confining pressure cavity 31, which has a cylindrical structure; a hollow stress sensor 4 is disposed through the confining pressure cavity 31 along its axial direction; one end of the confining pressure cavity 31 is located in one of the accommodating spaces, and the other end of the confining pressure cavity 31 is located in another accommodating space; both ends of the confining pressure cavity 31 abut against the lower half-ring clamp 21 and the upper half-ring clamp 22; a pressure inlet 101 is provided on the confining pressure cavity 31, which is connected to a hydraulic loading system; a pressure sensor is disposed inside the pressure inlet 101.
[0029] Specifically, the two ends of the confining pressure chamber are shaped to match the accommodating space formed by the lower and upper half of the ring clamps. The hollow infill stress sensor is installed through the confining pressure chamber along its axial direction, ensuring uniform pressure distribution within the chamber. Both ends of the hollow infill stress sensor are located outside the chamber, facilitating alignment of its axis with the chamber's axis during installation. The hydraulic loading system delivers confining pressure to the hollow infill stress sensor within the confining pressure chamber through a pressure inlet. This system controls the confining pressure by inputting a pressure medium into the chamber and applying confining pressure to the outer wall of the hollow infill. A pressure sensor is used to test the pressure within the confining pressure chamber, enabling graded loading, pressure stabilization control, and pressure monitoring.
[0030] In one possible implementation, the confining pressure chamber 3 further includes: two pressure caps 32, each pressure cap 32 having a circular ring structure; one pressure cap 32 is sleeved around one end of the hollow infill stress sensor 4 and detachably connected to the confining pressure cavity 31; the other pressure cap 32 is sleeved around the other end of the hollow infill stress sensor 4 and detachably connected to the confining pressure cavity 32; two circular washers 33, each circular washer 33 having a circular ring structure; one circular washer 33 is sleeved around one end of the hollow infill stress sensor 4; the other circular washer 33 is sleeved around the other end of the hollow infill stress sensor 4; any one of the circular washers 33 is located between the pressure cap 32 and the hollow infill stress sensor 4, and abuts against the pressure cap 32 and the hollow infill stress sensor 4 respectively.
[0031] Specifically, the pressure cap is fitted onto both ends of the hollow-body stress sensor and connected to the confining pressure cavity, confining the hollow-body stress sensor within the confining pressure cavity and simultaneously sealing the confining pressure cavity. Circular gaskets are fitted onto both ends of the hollow-body stress sensor and located between the pressure cap and the hollow-body stress sensor, further improving the sealing performance at the ends of the confining pressure cavity, preventing leakage of the pressure medium during calibration, and ensuring the stability of the confining pressure loading process.
[0032] In one possible implementation, the upper surface of the base 1 is provided with two sets of support grooves, and the two sets of support grooves are arranged one-to-one with the two sets of support frames; each set of support grooves includes two square grooves 102; wherein, each set of support frames includes two movable supports 5, and the two movable supports 5 are respectively located at the lower ends of a corresponding lower half ring clamp 21; each square groove 102 is adapted to a corresponding movable support 5; one end of each movable support 5 is detachably connected to the lower half ring clamp 21, and the other end of each movable support 5 is located in a corresponding square groove 102 and is movably connected to the base 1, so that the lower half ring clamp 21 can freely micro-displace along the axial direction of the hollow package stress sensor 4.
[0033] Specifically, one end of the movable bracket is movably connected to the lower half of the ring holder, and the other end of the movable bracket is movably connected to the base plate in the square groove. The movable bracket is adapted to the square groove, so that the movable bracket can only tilt and shift along the axial direction of the hollow package stress sensor within the square groove. This allows the lower half of the ring holder to undergo free micro-displacement along the axial direction of the hollow package stress sensor, thereby reducing the constraint effect of the lower half of the ring holder on the axial deformation of the hollow package. This makes the actual deformation state of the hollow package stress sensor under confining pressure loading conditions closer to the theoretical state of a thick-walled cylinder under uniform confining pressure.
[0034] In one possible implementation, the indoor non-destructive calibration device for the hollow inclusion stress sensor includes one calibration unit; one end of the hollow inclusion stress sensor 4 has a stress data acquisition line outlet 103, and the hollow inclusion stress sensor 4 is connected to an external data acquisition system via a first stress data acquisition line; the stress data acquisition line outlet 103 is used for the first stress data acquisition line to pass through; or, the indoor non-destructive calibration device for the hollow inclusion stress sensor includes at least two calibration units, each of the hollow inclusion stress sensors 4 having a stress data acquisition line outlet 103 at one end; any two adjacent hollow inclusion stress sensors 4 are connected in series via a second data acquisition line, and the two hollow inclusion stress sensors 4 located at the two ends of the series connection are respectively connected to an external data acquisition system via a third data acquisition line; each of the second data acquisition line and each of the third data acquisition lines passes through the corresponding stress data acquisition line outlet 103.
[0035] Specifically, the stress data acquisition line outlet is used to lead out the first stress data acquisition line, the second stress data acquisition line, and the third stress data acquisition line; the external data acquisition system is used to monitor and acquire the data output by the hollow inclusion stress sensor; when the indoor non-destructive calibration device for the hollow inclusion stress sensor includes one calibration unit, the external data acquisition system monitors and acquires the data of only one hollow inclusion stress sensor; when the indoor non-destructive calibration device for the hollow inclusion stress sensor includes two or more calibration units, all calibration units are connected in series, and the external data acquisition system monitors and acquires the data of all hollow inclusion stress sensors, and simultaneously calibrates each hollow inclusion stress sensor separately using the acquired data.
[0036] Example 2 Embodiment 2 of the present invention provides a method for using an indoor non-destructive calibration device for a hollow infill stress sensor, which is used in the indoor non-destructive calibration device for a hollow infill stress sensor described in Embodiment 1. The method includes: assembling the hollow infill stress sensor to be calibrated in the corresponding calibration unit, aligning the axis of the hollow infill stress sensor with the center line connecting the two corresponding accommodating spaces to complete the calibration preparation; gradually applying confining pressure to the confining pressure chamber using a hydraulic loading system in a graded loading manner, maintaining pressure stability under each level of confining pressure, and synchronously acquiring the output data of each strain measurement channel of the hollow infill stress sensor through an external data acquisition system to establish the correspondence between the measured strain of each strain measurement channel of the hollow infill stress sensor and the confining pressure; and based on the hollow infill... Based on the theory of thick-walled cylinders under uniform confining pressure, the relationship between the theoretical strain and confining pressure of each strain measurement channel of the hollow infill stress sensor is established, and the theoretical slope coefficients corresponding to each strain measurement channel of the hollow infill stress sensor are obtained. Linear fitting is performed on the measured strain and confining pressure data of each strain measurement channel of the hollow infill stress sensor to obtain the experimental fitting slope corresponding to each strain measurement channel of the hollow infill stress sensor. Based on the theoretical slope coefficients and experimental fitting slopes, the calibration coefficients of the hollow infill stress sensor are obtained, and the measured strain of each strain measurement channel of the hollow infill stress sensor is corrected using the calibration coefficients. The calibrated hollow infill stress sensor is then taken out. The theoretical strain of any strain measurement channel of the hollow infill stress sensor is... for: ; wherein, the φ i The angle between the i-th strain measurement channel and the axis of the hollow inclusion stress sensor; the The axial strain is the inner surface of the hollow-body stress sensor. The internal pressure is 0; The circumferential strain is the inner surface of the hollow inclusion stress sensor. The internal pressure is 0; 'a' is the inner radius of the hollow cylinder of the hollow cavity stress sensor; 'R' is... s The hollow cylinder of the hollow inclusion stress sensor has an outer radius of 1; E2 is the elastic modulus; v2 is Poisson's ratio; p is the confining pressure; based on The theoretical strain of any strain measurement channel of the hollow inclusion stress sensor satisfies a linear relationship with the confining pressure: ; wherein, the For the theoretical strain of the i-th channel, the Let be the slope coefficient of the theoretical strain versus confining pressure relationship for the i-th channel; the linear fitting formula for the measured strain versus confining pressure for any strain measurement channel of the hollow inclusion stress sensor is: ; wherein, the For the measured strain of the i-th channel, the Let b be the slope of the fitted test for the i-th channel. i The fitting intercept; the fitting intercept Ignoring the timing, the calibration coefficient for: .
[0037] Specifically, the two ends of the confining pressure chamber are fixed in the accommodating space of two fixed components, and then the two fixed components are movably connected to the base through two sets of support frames; the hollow infill stress sensor to be calibrated is inserted through the confining pressure chamber along the axial direction of the confining pressure chamber, so that the axis of the hollow infill stress sensor is aligned with the center line of the two accommodating spaces; a circular washer and a pressure cap are assembled, and the pressure inlet is connected to the hydraulic loading system; the sealing of each connection and the confining pressure chamber is checked to complete the calibration preparation; confining pressure is gradually applied to the confining pressure chamber using a graded loading method, and the pressure is kept stable under each level of confining pressure, while the output data of each strain measurement channel is collected simultaneously to establish the correspondence between the measured strain of each channel and the confining pressure; the hollow infill stress sensor is simplified into a thick-walled cylindrical model with open ends, and the model is constructed according to the hollow infill stress sensor... Based on the theory of thick-walled cylinders under uniform confining pressure, the relationship between theoretical strain and confining pressure for each strain measurement channel is established, and the theoretical slope coefficient corresponding to each channel is obtained. Linear fitting is performed on the measured strain and confining pressure data for each strain measurement channel to obtain the experimental fitting slope for each channel. Based on the theoretical slope coefficient and the experimental fitting slope, the calibration coefficient for each channel is obtained, and the measured strain for each channel is corrected using the calibration coefficient. After obtaining the calibration coefficient for each channel, the calibration coefficient corresponding to each channel can be written into the data processing program, solution model, or parameter configuration file corresponding to the sensor, and used as calibration parameters for subsequent strain calculation and stress inversion of the hollow infill stress sensor. The confining pressure is removed, the pressure cap and clamp are disassembled, and the calibrated hollow infill stress sensor is taken out. The calibrated hollow infill stress sensor can still be used normally.
[0038] It should be noted that the method of using the indoor non-destructive calibration device for hollow inclusion stress sensors in this second embodiment is used in the same way as the indoor non-destructive calibration device for hollow inclusion stress sensors described in the first embodiment. Therefore, the performance principle of the indoor non-destructive calibration device for hollow inclusion stress sensors will not be repeated here, and the parts not described in detail can be referred to the first embodiment.
[0039] In summary, the indoor non-destructive calibration device for a hollow infill stress sensor of the present invention has the following advantages: 1. This invention combines detachable clamping with confining pressure sealing loading, eliminating the need to bond and fix the hollow infill stress sensor inside concrete or other specimens, thus achieving non-destructive calibration of the hollow infill stress sensor; 2. After calibration, the hollow stress sensor can be completely disassembled and used for subsequent engineering tests, making it possible to calibrate each sensor individually. This overcomes the shortcomings of traditional bonded and fixed type sensors, which cannot be reused after calibration and can only be sampled for calibration. 3. By designing the fixed components and the base as movable supports for connection, the present invention effectively reduces the additional constraints of the fixed components on the axial deformation of the hollow cavity stress sensor, making the actual stress and deformation state of the hollow cavity stress sensor closer to the theoretical conditions of a thick-walled cylinder under uniform confining pressure, thereby improving the consistency between the calibration results and the theoretical values.
[0040] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.
Claims
1. An indoor non-destructive calibration device for a hollow infill stress sensor, characterized in that, The hollow infill stress sensor indoor non-destructive calibration device is assembled from at least one calibration unit, which includes: A base, which is parallel to a horizontal ground; Two fixing components are located on the upper surface of the base and are arranged parallel to each other; each fixing component has an accommodating space in the middle. Two sets of support frames are arranged one-to-one with two fixed components, and each fixed component is movably connected to the base through a corresponding set of support frames. A confining pressure chamber is provided, in which a hollow infill stress sensor is installed through the confining pressure chamber along its axial direction; one end of the confining pressure chamber is located in one of the accommodating spaces, and the other end of the confining pressure chamber is located in another of the accommodating spaces.
2. The indoor non-destructive calibration device for a hollow package stress sensor as described in claim 1, characterized in that, Each of the aforementioned fixing components includes: The lower half of the ring clamp has a concave semi-circular structure at the upper middle part; the lower part of the lower half of the ring clamp is movably connected to the base through a corresponding set of support frames. The upper half of the ring clamp has a concave semi-circular structure at its lower middle part; the upper half of the ring clamp is located above the lower half of the ring clamp and together with the lower half of the ring clamp forms the accommodating space; the upper half of the ring clamp and the lower half of the ring clamp are detachably connected. Both ends of the confining chamber abut against the corresponding lower half ring clamp and the corresponding upper half ring clamp.
3. The indoor non-destructive calibration device for a hollow package stress sensor as described in claim 2, characterized in that, The confining pressure chamber includes: The confining pressure chamber has a cylindrical structure, and the hollow-body stress sensor is installed through the confining pressure chamber along the axial direction of the confining pressure chamber; one end of the confining pressure chamber is located in one of the accommodating spaces, and the other end of the confining pressure chamber is located in another accommodating space; Both ends of the confining pressure cavity abut against the lower half of the ring clamp and the upper half of the ring clamp; the confining pressure cavity is provided with a pressure inlet, which is connected to the hydraulic loading system; a pressure sensor is installed inside the pressure inlet.
4. The indoor non-destructive calibration device for a hollow package stress sensor as described in claim 3, characterized in that, The confining chamber also includes: Two pressure caps, each of which is a ring structure. One pressure cap is sleeved on the periphery of one end of the hollow package stress sensor and is detachably connected to the confining pressure cavity. The other pressure cap is sleeved on the periphery of the other end of the hollow package stress sensor and is detachably connected to the confining pressure cavity. Two circular washers, each of which has a ring structure, are provided. One circular washer is fitted around one end of the hollow package stress sensor, and the other circular washer is fitted around the other end of the hollow package stress sensor. Either circular washer is located between the pressure cap and the hollow package stress sensor, and abuts against the pressure cap and the hollow package stress sensor respectively.
5. The indoor non-destructive calibration device for a hollow package stress sensor as described in claim 4, characterized in that, The upper surface of the base is provided with two sets of support grooves, and the two sets of support grooves are arranged in a one-to-one correspondence with the two sets of support frames; each set of support grooves includes two square grooves. Each set of support frames includes two movable supports, which are located at the lower ends of a corresponding lower half ring holder. Each square groove is adapted to a corresponding movable support. One end of each movable support is detachably connected to the lower half ring holder, and the other end of each movable support is located in a corresponding square groove and is movably connected to the base, so that the lower half ring holder can freely micro-displace along the axial direction of the hollow package stress sensor.
6. The indoor non-destructive calibration device for a hollow infill stress sensor as described in claim 5, characterized in that: The indoor non-destructive calibration device for the hollow inclusion stress sensor includes a calibration unit; one end of the hollow inclusion stress sensor is provided with a stress data acquisition line outlet, and the hollow inclusion stress sensor is connected to an external data acquisition system through a first stress data acquisition line; The outlet of the stress data acquisition line is used for the passage of the first stress data acquisition line; or, The indoor non-destructive calibration device for hollow inclusion stress sensors includes at least two calibration units. Each hollow inclusion stress sensor has a stress data acquisition line outlet at one end. Any two adjacent hollow inclusion stress sensors are connected in series via a second data acquisition line, and the two hollow inclusion stress sensors located at the two ends of the series connection are respectively connected to an external data acquisition system via a third data acquisition line. Each second data acquisition line and each third data acquisition line passes through the corresponding stress data acquisition line outlet.
7. A method of using an indoor non-destructive calibration device for a hollow inclusion stress sensor, used in accordance with the indoor non-destructive calibration device for a hollow inclusion stress sensor as described in claim 6, characterized in that... The method of use includes: Assemble the hollow inclusion stress sensor to be calibrated in the corresponding calibration unit, align the axis of the hollow inclusion stress sensor with the center line connecting the two corresponding accommodating spaces, and complete the calibration preparation. The confining pressure is gradually applied to the confining chamber using a staged loading method through a hydraulic loading system. The pressure is kept stable under each level of confining pressure. The output data of each strain measurement channel of the hollow inclusion stress sensor is collected synchronously through an external data acquisition system to establish the correspondence between the measured strain of each strain measurement channel of the hollow inclusion stress sensor and the confining pressure. Based on the theory of thick-walled cylinders under uniform confining pressure, the relationship between the theoretical strain and confining pressure of each strain measurement channel of the hollow inclusion stress sensor is established, and the theoretical slope coefficients corresponding to each strain measurement channel of the hollow inclusion stress sensor are obtained. Linear fitting was performed on the measured strain and confining pressure data of each strain measurement channel of the hollow inclusion stress sensor to obtain the experimental fitting slope corresponding to each strain measurement channel of the hollow inclusion stress sensor. Based on the theoretical slope coefficient and the experimental fitting slope, the calibration coefficient of the hollow inclusion stress sensor is obtained, and the measured strain of each strain measurement channel of the hollow inclusion stress sensor is corrected using the calibration coefficient. Remove the calibrated hollow ingot stress sensor.
8. The method of using the indoor non-destructive calibration device for a hollow package stress sensor as described in claim 7, characterized in that: The theoretical strain of any strain measurement channel of the hollow inclusion stress sensor for: ； Wherein, the φ i The angle between the i-th strain measurement channel and the axis of the hollow inclusion stress sensor; the The axial strain is the inner surface of the hollow-body stress sensor. The internal pressure is 0; The circumferential strain is the inner surface of the hollow inclusion stress sensor. The internal pressure is 0; 'a' is the inner radius of the hollow cylinder of the hollow cavity stress sensor; 'R' is... s is the outer radius of the hollow cylinder of the hollow package stress sensor; E2 is the elastic modulus; v2 is Poisson's ratio; p is the confining pressure; based on The theoretical strain of any strain measurement channel of the hollow inclusion stress sensor satisfies a linear relationship with the confining pressure: ; wherein, the For the theoretical strain of the i-th channel, the is the slope coefficient of the theoretical strain versus confining pressure relationship for the i-th channel.
9. The method of using the indoor non-destructive calibration device for a hollow package stress sensor as described in claim 8, characterized in that, The linear fitting formula between the measured strain and confining pressure of any strain measurement channel of the hollow inclusion stress sensor is as follows: ； Among them, the For the measured strain of the i-th channel, the Let b be the slope of the fitted test for the i-th channel. i The intercept is the fitting angle.
10. The method of using the indoor non-destructive calibration device for a hollow package stress sensor as described in claim 9, characterized in that, The fitting intercept Ignoring the timing, the calibration coefficient for: 。