High and low temperature strain calibration device based on pure bending beam
Through a high and low temperature strain calibration device based on pure bend beams, the air-floating support structure and laser ranging assembly are used to solve the problem of the impact of measurement accuracy in high and low temperature environments in the existing technology, and high-precision strain calibration and complex environments are achieved strain traceability.
Patent Information
- Application Number
- CN202410190317.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-02-20
- Publication Date
- 2024-12-17
- Estimated Expiration
- 2044-02-20
Smart Images
Figure CN118009910B_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of strain calibration, and in particular to a high and low temperature strain calibration device based on a pure bending beam. Background Art
[0002] Strain gauge is an instrument that measures the deformation caused by changes in stress inside a structure. It has the characteristics of high accuracy, good stability and repeatability. There are many types of strain gauges, among which resistance strain gauges and fiber Bragg grating strain sensors are the most widely used. They can be used in various industries such as health monitoring, structural strength testing, various fatigue tests, load spectrum testing, etc. Therefore, the calibration of strain gauges is of great significance.
[0003] At present, there are three main types of devices used for strain gauge calibration at home and abroad: the first type is the tensile beam form, which causes the beam to undergo tensile deformation with a small amount of stretching, and its measurement is prone to introduce other structural deformations. These deformations are difficult to separate individually, which seriously affects the accuracy of the calibration results. The second type is the cantilever equal strength beam form, which generates the required strain by bending the cantilever beam. It is necessary to calculate the strain on the surface of the bending moment beam based on the size of the beam, the elastic modulus of the beam material, and the load of the beam, but the accuracy of the elastic modulus of the beam cannot be guaranteed, which affects the accuracy of the strain gauge calibration results. The third type is the pure bending beam form, which is mainly based on the four-point equal bending moment simply supported beam principle or the rigid frame beam equal bending moment principle. It requires high support stiffness and high measurement accuracy, but the structure is relatively complex and it is difficult to meet the testing requirements of high and low temperature environments.
[0004] In order to identify the loading strain, several existing calibration devices need to measure the deformation of the beam. Currently, the contact measurement method is mainly used. Since the contact measuring instrument is easily affected by temperature changes, the deformation measurement accuracy will be affected when the temperature is high or low. The contact measuring instrument cannot work normally at high and low temperature extremes. Therefore, it is necessary to use a non-contact measurement method to replace the contact measurement method to meet the deformation measurement in complex working environments. Summary of the invention
[0005] In view of this, the present application proposes a high and low temperature strain calibration device based on a pure bending beam, comprising a base, a driving part, a screw, an air-floating support structure, a loading arm, a measured beam, a fixed bracket and a laser ranging assembly; the upper surface of the base is horizontal, the driving part and the screw are installed on the base, the screw is connected to the output shaft of the driving part by transmission, the screw is a straight rod structure, and the two ends of the screw extend to the opposite sides of the driving part respectively; the air-floating support structure comprises a first support member and a second support member; the bottom of the loading arm is installed on the base through the first support member, the loading arm is a straight arm structure, and the number of There are two loading force arms, the loading force arms are perpendicular to the lead screw, one end of the two loading force arms is respectively connected to the lead screws on both sides of the driving part, the other end of the loading force arm is provided with a clamping part, and the two loading force arms clamp the measured beam together; the rotation of the lead screw can drive the two loading force arms to be relatively close or drive the two loading force arms to be relatively far away, and the loading force arms always remain perpendicular to the lead screw; the bottom of the fixed bracket is installed on the base through the second support member; the laser ranging assembly is installed on the fixed bracket, and the measuring end of the laser ranging assembly is vertically facing the measured beam.
[0006] In a possible implementation, it also includes an ambient temperature control mechanism and an insulating coupling; the measured beam includes a middle section and a left end section and a right end section located at both ends of the middle section; the left end section is connected to the middle section through the insulating coupling shaft, and the right end section is connected to the middle section through the insulating coupling shaft; the middle section is located inside the ambient temperature control mechanism, the left end section is thermally insulated and connected to the outside of the ambient temperature control mechanism through the insulating coupling, the right end section is thermally insulated and connected to the outside of the ambient temperature control mechanism through the insulating coupling, and the left end section and the right end section are respectively clamped by the loading force arms located on both sides.
[0007] In a possible implementation manner, the loading force arms are symmetrically arranged at two ends of the driving part.
[0008] In one possible implementation, the lead screw is a bidirectional lead screw, and the working surfaces of the lead screw on both sides of the driving part are arranged oppositely; it also includes a positioning member; the positioning member is passed through the lead screw, and the two positioning members are respectively clamped and fixed from both sides of the same loading force arm.
[0009] In a possible implementation manner, a strain gauge to be measured is attached to the beam to be measured.
[0010] In a possible implementation, the ambient temperature control mechanism has a window plate, and the measuring end of the laser ranging assembly is arranged toward the window plate of the ambient temperature control mechanism.
[0011] In a possible implementation, the first support member is a columnar structure, there are multiple of them, and they are arranged at the bottom of the loading arm; the second support member is a columnar structure, there are multiple of them, and they are arranged at the bottom of the fixed bracket.
[0012] In a possible implementation, the fixed bracket has a "∏"-shaped structure, the two ends of the blade are respectively adjacent to the two loading force arms, and the laser ranging assembly is arranged at the midpoint of the two loading force arms.
[0013] In a possible implementation, it further includes a support seat; the support seat is on the base, and the air-floating support structure is arranged on the support seat, and the air-floating support structure is a flat air-floating support member or a columnar air-floating support member.
[0014] In a possible implementation manner, a strain demodulation device is further included; the strain demodulation device is electrically connected to the strain gauge to be measured.
[0015] Beneficial effects of the present application: The working process of the high and low temperature strain calibration device based on pure bending beam of the present application is as follows: the strain gauge to be calibrated is installed in the middle section of the measured beam, the left end section, the right end section and the middle section of the measured beam are connected into a system through a rigid heat-insulating coupling, and the system is fixed between two loading force arms through a clamping part, and the laser distance measuring component (laser displacement meter) is adjusted by adjusting the position of the fixed bracket. ) The measuring point is located at the center of the beam being measured.
[0016] Moreover, an environmental temperature control mechanism is installed to ensure that the entire middle section of the measured beam is placed inside the environmental temperature control mechanism, and the strain demodulation device is connected to the calibrated strain gauge so that the output of the calibrated strain gauge is zero. As the initial state of calibration, different bending moments are applied to the left and right ends of the measured beam by adjusting the driving force and speed of the driving unit through the control system to generate the required strain, and the environmental temperature control mechanism is adjusted to generate the required temperature environment, thereby realizing strain calibration under different temperature conditions.
[0017] (1) The device of the present application adopts an air-floating support structure. Compared with the ball support structure, it can effectively avoid the use of balls for multi-point support. The support heights of multiple balls are difficult to maintain in the same plane. Therefore, the air-floating support structure is easier to process and easier to achieve that the loading arms at both ends are in the same horizontal plane, and ensure that the loading arms and the measured beam are in a highly symmetrical state. In addition, the horizontal friction of the two arms during the loading process can be ignored, reducing the generation of strains in other directions, and effectively ensuring the directionality of standard strain loading and the accuracy of control;
[0018] (2) The device of the present application adopts a pure bending strain beam structure, so that the middle section of the measured beam can produce a longer equal strain area, reducing the error introduced by the installation position of the strain gauge. Since the equal strain area is large, multiple strain gauges can be measured synchronously, improving work efficiency. In addition, the pure bending strain beam structure can also quickly realize concave and convex bidirectional deformation;
[0019] (3) The device of the present application adopts a segmented strain beam combination structure, which can realize strain calibration under different conditions by replacing the measured beams of different materials and cooperating with environmental test chambers required by different environments, such as high and low temperature chambers, high and low pressure chambers, humidity chambers, salt spray chambers, etc., which can realize strain traceability in complex environments and improve the calibration accuracy of strain gauges;
[0020] (4) The device of the present application adopts a laser ranging component, which is a non-contact measurement method. It can realize deflection measurement in temperature environments such as normal temperature, high temperature, and low temperature. The measurement accuracy is less affected by temperature, which solves the problem that the original contact deflection measurement method cannot meet the deflection measurement needs in high and low temperature environments.
[0021] Other features and aspects of the present application will become apparent from the following detailed description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments, features, and aspects of the present application and, together with the description, serve to explain the principles of the present application.
[0023] Figure 1 A schematic diagram of the top structure of a high and low temperature strain calibration device based on a pure bending beam according to an embodiment of the present application is shown. DETAILED DESCRIPTION
[0024] Various exemplary embodiments, features and aspects of the present application will be described in detail below with reference to the accompanying drawings. The same reference numerals in the accompanying drawings represent elements with the same or similar functions. Although various aspects of the embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless otherwise specified.
[0025] Among them, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application or simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.
[0026] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.
[0027] The word “exemplary” is used exclusively herein to mean “serving as an example, example, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.
[0028] In addition, in order to better illustrate the present application, numerous specific details are given in the following specific embodiments. It should be understood by those skilled in the art that the present application can also be implemented without certain specific details. In some examples, methods, means, components and circuits well known to those skilled in the art are not described in detail in order to highlight the subject matter of the present application.
[0029] like Figure 1As shown, the high and low temperature strain calibration device based on pure bending beam includes: a base 4, a driving part 11, a lead screw 12, an air-floating support structure 3, a loading arm 2, a measured beam, a fixed bracket 15 and a laser ranging assembly 16. The upper surface of the base 4 is horizontal, the driving part 11 and the lead screw 12 are installed on the base 4, the lead screw 12 is connected to the output shaft of the driving part 11 by driving, the lead screw 12 is a straight rod structure, and the two ends of the lead screw 12 extend to the opposite sides of the driving part 11 respectively. The air-floating support structure 3 includes a first support member and a second support member. The bottom of the loading arm 2 is installed on the base 4 through the first support member. The loading arm 2 is a straight arm The structure is two in number, the loading arm 2 and the lead screw 12 are perpendicular to each other, one end of the two loading arm 2 is respectively connected to the lead screw 12 on both sides of the driving part 11, and the other end of the loading arm 2 is provided with a clamping part 5, and the two loading arm 2 clamp the measured beam together, and the rotation of the lead screw 12 can drive the two loading arm 2 to be relatively close or drive the two loading arm 2 to be relatively far away, and the loading arm 2 always remains perpendicular to the lead screw 12, and the bottom of the fixed bracket 15 is installed on the base 4 through the second support member, and the laser ranging component 16 is installed on the fixed bracket 15, and the measuring end of the laser ranging component 16 is vertically facing the measured beam.
[0030] It should be particularly pointed out here that when the test is carried out at room temperature, the measured beam is usually a whole straight beam structure; when the test environment is higher or lower than room temperature, the measured beam will be divided into a middle section and two end sections, and only the middle section of the measured beam is located in the environmental temperature control mechanism 9. For ease of understanding and description, the middle section of the measured beam described in this article is the calibration beam 10, and the left end section and the right end section of the measured beam described in this article are both strain beams 6. In addition, the laser distance measurement component 16 can choose to use a laser displacement meter.
[0031] In this embodiment, the working process of the high and low temperature strain calibration device based on pure bending beam of the present application is as follows: the strain gauge 8 to be calibrated is installed in the strain area such as the calibration beam 10, the strain beam 6 and the calibration beam 10 are connected as a system through a rigid insulation coupling 7, and the system is fixed between the two loading force arms 2 through the clamping part 5, and the measuring point of the laser displacement meter is located at the center of the calibration beam 10 by adjusting the position of the fixed bracket 15, and the ambient temperature control mechanism 9 is installed to ensure that the calibration beam 10 is completely placed inside it, and the strain demodulation device 13 is connected to the strain gauge 8 to be calibrated, so that the output of the strain gauge 8 to be calibrated is zero, as the initial state of calibration, and the driving force and speed of the driving part 11 are adjusted by the control system 14 to apply different bending moments to the calibration beam 10 to generate the required strain, and the ambient temperature control mechanism 9 is adjusted to generate the required temperature environment, thereby realizing strain calibration under different temperature conditions.
[0032] (1) The device of the present application adopts an air-floating support structure 3, so that the loading force arms 2 at both ends are in the same horizontal plane, and the loading force arms 2 and the strain beam are in a highly symmetrical state. In addition, the horizontal friction of the two force arms during the loading process can be ignored, reducing the generation of strains in other directions, and effectively ensuring the directionality of standard strain loading and the accuracy of control;
[0033] (2) The device of the present application adopts a pure bending strain beam structure, so that the middle section of the strain beam can produce a longer equal strain area, reducing the error introduced by the installation position of the strain gauge. Since the equal strain area is large, multiple strain gauges can be measured synchronously, improving work efficiency. In addition, the pure bending strain beam 6 structure can also quickly realize concave and convex bidirectional deformation;
[0034] (3) The device of the present application adopts a segmented strain beam combination structure, which can realize strain calibration under different conditions by replacing the middle beam of different materials and cooperating with environmental test chambers required by different environments, such as high and low temperature chambers, high and low pressure chambers, humidity chambers, salt spray chambers, etc., which can realize strain traceability in complex environments and improve the calibration accuracy of strain gauges;
[0035] (4) The device of the present application adopts a laser ranging component 16, which is a non-contact measurement method. It can realize deflection measurement in temperature environments such as normal temperature, high temperature, and low temperature. The measurement accuracy is less affected by temperature, which solves the problem that the original contact deflection measurement method cannot meet the deflection measurement needs in high and low temperature environments.
[0036] In one specific embodiment, when the test environment of the measured shaft is at an unconventional temperature, the high and low temperature strain calibration device based on a pure bending beam of the present application also includes an ambient temperature control mechanism and an insulating coupling. The measured beam includes a middle section and a left end section and a right end section located at both ends of the middle section. The left end section is connected to the middle section through an insulating coupling shaft, and the right end section is connected to the middle section through an insulating coupling shaft. The middle section is located inside the ambient temperature control mechanism, the left end section is thermally insulated and connected to the outside of the ambient temperature control mechanism through an insulating coupling, and the right end section is thermally insulated and connected to the outside of the ambient temperature control mechanism through an insulating coupling. The left end section and the right end section are respectively clamped by the loading force arms 2 located on both sides.
[0037] In one specific embodiment, the loading arm 2 is symmetrically arranged at two ends of the driving part 11 .
[0038] In one specific embodiment, the lead screw 12 is a bidirectional lead screw, and the working surfaces of the lead screw 12 on both sides of the driving part 11 are oppositely arranged. A positioning member is also included; the positioning member is passed through the lead screw 12, and the two positioning members are respectively clamped and fixed on both sides of the same loading arm 2.
[0039] In this embodiment, a threaded hole is opened in the middle of the positioning member, and a threaded structure matching the lead screw, and a conical structure is raised on the surface of one side of the positioning member that fits with the loading force arm, and a recess matching the conical structure is provided at the position where the loading force arm contacts the positioning member, so that the positioning members located on both sides of the loading force arm can support the loading force arm from both sides, thereby ensuring that the loading force arm and the lead screw are perpendicular to each other as much as possible.
[0040] Preferably, the positioning member is a square structure with a threaded hole at the center of the positioning member. The positioning member is provided with the conical structure above and below the threaded hole, and the loading force arm is used to pass the through hole with recesses matching the conical structure above and below.
[0041] In one specific embodiment, a strain gauge is attached to the beam to be measured.
[0042] In one specific embodiment, the ambient temperature control mechanism 9 has a window plate, and the measuring end of the laser distance measuring assembly 16 is arranged toward the window plate of the ambient temperature control mechanism 9 .
[0043] In one specific embodiment, the first support member is a columnar structure member, there are multiple of them, arranged at the bottom of the loading arm, and the second support member is a columnar structure member, there are multiple of them, arranged at the bottom of the fixed bracket 15.
[0044] It should be noted that the ball support structure used in the prior art is replaced by an air-floating support structure, thereby avoiding the problems of high difficulty and long processing time required by the ball support structure. More specifically, the ball support structure requires multiple balls to cooperate for multi-point support, but multiple balls support together and ensure that the workpiece located thereon is completely horizontal, which requires a high level of ball processing and low production efficiency. In addition, the balls have relative friction in the process of the loading force arm 2 moving away from or approaching each other, while in the air-floating support structure, this friction can be ignored, thereby reducing the generation of strains in other directions of the measured beam, and effectively ensuring the directionality of standard strain loading and the accuracy of control.
[0045] In one specific embodiment, the fixed bracket 15 is in a “∏”-shaped blade structure, with two ends of the blade respectively adjacent to the two loading force arms 2 , and the laser ranging component 16 is disposed at the midpoint of the two loading force arms 2 .
[0046] In one specific embodiment, it also includes a support seat, the support seat is on the base, and the air floating support structure is arranged on the support seat, and the air floating support structure is a flat air floating support member or a columnar air floating support member. Figure 1 The figure shows a flat plate air-floating support.
[0047] In one specific embodiment, it further includes a strain demodulation device 13 , and the strain demodulation device 13 is electrically connected to the strain gauge to be measured.
[0048] In one specific embodiment, a high and low temperature strain calibration device based on a pure bending beam includes: a base 4, a transmission system, a loading arm 2, an air floating support structure 3, a clamping portion 5, a strain beam 6, a rigid thermal insulation coupling 7, a calibration beam 10, a calibrated strain gauge 8, an ambient temperature control mechanism 9, a fixed bracket 15, a laser ranging component 16, a strain demodulation device 13, and a control system 14. The transmission system includes a driving part 11 and a lead screw 12. The base 4 is used to provide an installation position for the components installed thereon to ensure that the calibration device is installed at a horizontal level. The bottom of the transmission system is fixedly installed on the base 4. The two ends of the transmission system pass through the loading force arms 2 respectively and can be driven by the control system 14 to generate corresponding loading forces. The loading force arms 2 are symmetrically distributed on both sides and installed above the air-floating support structure 3. One end of each loading force arm 2 is connected to the transmission system, and the other end is vertically fixedly connected to the strain beam 6 through the clamping part 5 to provide equal bending moment loading for the strain beam 6. The air-floating support structure 3 is fixedly installed above the base 4 and below the loading force arm 2 to ensure that the loading force arms 2 on both sides are in the same horizontal plane to reduce the friction generated during the loading process. The clamping part 5 is installed on the end face of the loading force arm 2 to fix the strain beam 6 to the loading force arm 2. The strain beam 6 is connected to the calibration beam 10 as a whole through the rigid insulation coupling 7, and is installed on both sides as a standard strain generation system. The rigid heat-insulating coupling 7 is used to ensure that the working surfaces of the strain beam 6 and the calibration beam 10 are at the same horizontal plane, and play a heat-insulating role under high and low temperature test conditions. The calibration beam 10 is used to achieve equal strain under high and low temperature test conditions; the calibrated strain gauge 8 is installed on the deformation surface of the equal strain area of the calibration beam 10; the environmental temperature control mechanism 9 is installed at the calibration beam 10 to ensure that the calibration beam 10 is completely in the environmental temperature control mechanism 9 to provide the required different high and low temperature test environments; the laser distance measurement component 16 is fixedly installed on the fixed bracket 15, and the two are installed as a whole above the air-floating support structure 3 to ensure that the laser distance measurement component 16 and the calibration beam 10 are in the same working plane, wherein the fixed bracket 15 is used to ensure that the laser distance measurement component 16 and the calibration beam 10 move synchronously; the strain demodulation device 13 is used for signal demodulation and display of the calibrated strain gauge 8; the control system 14 is used to control the transmission system to generate the required driving force to ensure the generation of different strain values. Preferably, the calibration beam 10 is composed of N rectangular cross-section beams of different sizes and different materials, where N is an integer greater than or equal to 3. When conducting a calibration test over a wide strain range within a fixed temperature range, a calibration beam 10 with the same material but different thickness is preferred. When conducting a calibration test over a wide temperature range with a fixed strain range, a square cross-section calibration beam 10 with the same size but different materials is preferred.Preferably, the environmental temperature control mechanism 9 is composed of N temperature chambers with completely identical appearance dimensions and structures to ensure the test conditions of high and low temperature limits. To ensure a wider temperature test range, better temperature uniformity and stability, N is an integer greater than or equal to 3. When the calibration device is used, temperature chambers of different specifications are used to provide calibration conditions for different temperature ranges.
[0049] A high and low temperature strain calibration device based on a pure bending beam mainly includes a transmission system, a loading arm 2, an air floating support structure 3, a base 4, a clamping part 5, a strain beam 6, a rigid thermal insulation coupling 7, a calibrated strain gauge 8, an ambient temperature control mechanism 9, a calibration beam 10, a fixed bracket 15, a laser ranging component 16, a strain demodulation device 13, and a control system 14. Place the base 4 on the horizontal ground to ensure that the calibration device is installed on a horizontal basis. The transmission system and the bottom of the air-floating support structure 3 are fixedly installed on the base 4. The two ends of the transmission system pass through two loading force arms 2 respectively and are connected in a line contact manner. The loading force arms 2 are symmetrically distributed on both sides and installed above the air-floating support structure 3. The strain gauge 8 to be calibrated is installed in the equal strain area of the calibration beam 10. The strain beam 6 and the calibration beam 10 are connected as a system through a rigid heat-insulating coupling 7. The system is fixed between the two loading force arms 2 through the clamping part 5. The laser distance measurement component 16 is fixedly installed on the fixed bracket 15. The two are installed as a whole above the air-floating support structure 3 to ensure that the laser distance measurement component 16 and the calibration beam 10 are in the same working position. The calibration beam 10 is made into a plane and the laser distance measuring component 16 is ensured to move synchronously with the calibration beam 10. The measuring point of the laser distance measuring component 16 is located at the center of the calibration beam 10 by adjusting the position of the fixed bracket 15. The ambient temperature control mechanism 9 is installed to ensure that the calibration beam 10 is completely placed inside the ambient temperature control mechanism 9. The strain demodulation device 13 is connected to the calibrated strain gauge 8 so that the output of the calibrated strain gauge 8 is zero, which is used as the initial state of calibration. The transmission system is connected to the control system 14 and normal communication is ensured. The control system 14 adjusts the driving force and speed of the driving part 11 to apply different bending moments to the calibration beam 10 to generate the required strain. The ambient temperature control mechanism 9 is adjusted to generate the required temperature environment, thereby realizing strain calibration under different temperature conditions.
[0050] In this embodiment, the measured beam is composed of 5 square cross-section beams of different sizes and different materials. When a calibration test is performed over a wide strain range within a fixed temperature range, a calibration beam 10 with the same material but different thickness is selected for calibration test. When a calibration test is performed over a wide temperature range within a fixed strain range, a square cross-section calibration beam 10 with the same size, thickness and different material is selected for calibration test.
[0051] In this embodiment, the environmental temperature control mechanism 9 is composed of three temperature boxes with completely identical appearance dimensions and structures to ensure the test conditions of high and low temperature limits, and is used to provide low temperature, medium temperature and high temperature calibration conditions respectively.
[0052] In this embodiment, if normal temperature strain calibration is performed, the ambient temperature control mechanism 9 is removed from the calibration device, and a longer calibration beam 10 can be used to replace the strain beam 6. The system consisting of the calibration beam 10 and the rigid insulation coupling 7 can realize normal temperature wide range static strain calibration.
[0053] In this embodiment, if strain calibration is performed in a complex environment, the existing high and low temperature environment temperature control mechanism 9 is replaced by an environment temperature control mechanism for the required complex environment in the calibration device to provide the required complex environment, thereby realizing a wide range of static strain calibration in a complex environment.
[0054] The embodiments of the present application have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.
Claims
1. A high and low temperature strain calibration device based on a pure bending beam, characterized in that: It includes a base, a driving part, a lead screw, an air-floating support structure, a loading arm, a beam to be measured, a fixing bracket and a laser ranging component; The upper surface of the base is horizontal, the driving part and the lead screw are mounted on the base, the lead screw is drivingly connected to the output shaft of the driving part, the lead screw is a straight rod structure, and both ends of the lead screw extend to opposite sides of the driving part respectively; The air-floating support structure comprises a first support member and a second support member; The bottom of the loading force arm is installed on the base through the first support member. The loading force arm is a straight arm structure, and there are two of them. The loading force arm and the lead screw are perpendicular to each other. One end of the two loading force arms is respectively connected to the lead screws on both sides of the driving part. The other end of the loading force arm is provided with a clamping part, and the two loading force arms clamp the measured beam together. The rotation of the lead screw can drive the two loading force arms to be relatively close to each other or drive the two loading force arms to be relatively far away from each other, and the loading force arms always remain perpendicular to the lead screw; The bottom of the fixing bracket is mounted on the base through the second supporting member; The laser distance measuring assembly is mounted on the fixed bracket, and the measuring end of the laser distance measuring assembly is vertically oriented toward the measured beam; It also includes an ambient temperature control mechanism and a heat-insulating coupling; The measured beam comprises a middle section and a left end section and a right end section located at two ends of the middle section; The left end section is connected to the middle section via the heat-insulating coupling shaft, and the right end section is connected to the middle section via the heat-insulating coupling shaft; The middle section is located inside the ambient temperature control mechanism, the left end section is thermally insulated and connected to the outside of the ambient temperature control mechanism through the thermal insulation coupling, the right end section is thermally insulated and connected to the outside of the ambient temperature control mechanism through the thermal insulation coupling, and the left end section and the right end section are respectively clamped by the loading force arms located on both sides; The measured beam is attached with a measured strain gauge; The first support member is a columnar structure member, there are multiple of them, and they are arranged at the bottom of the loading arm. The second support member is a columnar structure member, there are multiple of them, and they are arranged at the bottom of the fixed bracket.
2. The high and low temperature strain calibration device based on pure bending beam according to claim 1 is characterized in that: The loading force arms are symmetrically arranged at two ends of the driving part.
3. The high and low temperature strain calibration device based on pure bending beam according to claim 1 is characterized in that: The lead screw is a bidirectional lead screw, and the working surfaces of the lead screw on both sides of the driving part are arranged oppositely; Also includes a positioning member; The positioning member is passed through the lead screw, and the two positioning members are respectively clamped and fixed on both sides of the same loading force arm.
4. The high and low temperature strain calibration device based on pure bending beam according to claim 1 is characterized in that: The environmental temperature control mechanism has a window plate, and the measuring end of the laser distance measuring component is arranged toward the window plate of the environmental temperature control mechanism.
5. The high and low temperature strain calibration device based on pure bending beam according to any one of claims 1 to 4, characterized in that: The fixed bracket is in a "∏"-shaped structure, and the two ends of the blade are respectively adjacent to the two loading force arms, and the laser ranging component is arranged at the midpoint of the two loading force arms.
6. The high and low temperature strain calibration device based on pure bending beam according to any one of claims 1 to 4, characterized in that: Also includes a support base; The support seat is on the base, and the air-floating support structure is arranged on the support seat. The air-floating support structure is a flat air-floating support member or a columnar air-floating support member.
7. The high and low temperature strain calibration device based on pure bending beam according to claim 1 is characterized in that: Also included is a strain demodulation device; The strain demodulation device is electrically connected to the strain gauge to be measured.