Multi-field loading in-situ collaborative characterization testing device and method based on Raman spectrum
By designing a multi-field loading in-situ collaborative characterization test device based on Raman spectroscopy, the problem of in-depth research on the sensitivity of mechanical parameters of biomass materials such as bamboo and wood was solved, and the in-situ dynamic characterization of the molecular configuration changes of biomass materials during mechanical loading was realized.
Patent Information
- Application Number
- CN202511147984.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-16
- Publication Date
- 2025-09-30
AI Technical Summary
In the existing technology, the sensitivity of Raman spectroscopy to the mechanical parameters of biomass materials such as bamboo and wood has not been systematically and in-depth studied, and there is a lack of suitable testing equipment and methods.
A multi-field loading in-situ collaborative characterization test device based on Raman spectroscopy was designed, which included a test base, a loading platform, a stepper motor and a Raman spectrometer. Temperature and humidity were adjusted through airflow control channels and thermocouples. Mechanical loading was performed in combination with a thrust rod and a loading head, and Raman spectral changes were monitored in real time.
It realizes the in-situ dynamic characterization of the changes in molecular configuration of macroscopic samples of biomass materials such as bamboo and wood during bending/tensile stress transmission during temperature and humidity changes, providing a convenient testing method.
Smart Images
Figure CN120721488A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of spectral mechanics, and in particular relates to a multi-field loading in-situ collaborative characterization test device and method based on Raman spectroscopy. Background Art
[0002] The multi-scale in situ characterization of heterogeneous, hierarchical structures under multi-field coupling conditions has always been difficult. Establishing a systematic characterization technique from the macroscopic to the microscopic is crucial for achieving quantitative descriptions at the molecular scale and can lead to significant breakthroughs in fundamental theoretical research. Currently, spectroscopic mechanical measurement and analysis techniques are developing rapidly and are beginning to be used in a variety of materials fields. Micro-Raman spectroscopy, in particular, is easily coupled with mechanical or other devices, making it suitable for in situ, online mechanical characterization.
[0003] However, the sensitivity of Raman spectroscopy to the mechanical parameters of biomass materials such as bamboo and wood has not been systematically and in-depth studied, and the testing method and testing equipment are still missing.
[0004] Based on this, a multi-field loading in-situ collaborative characterization test device and method based on Raman spectroscopy are proposed, which is suitable for Raman spectroscopy multi-field loading in-situ collaborative characterization test of biomass materials such as bamboo and wood. Summary of the Invention
[0005] The technical problem to be solved by the present invention is to address the deficiencies of the above-mentioned prior art and provide a multi-field loading in-situ collaborative characterization test device and method based on Raman spectroscopy to solve the problems raised in the above-mentioned background technology.
[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: In the first aspect, a multi-field loading in-situ collaborative characterization test device based on Raman spectroscopy includes a test base, a loading platform, a stepper motor and a Raman spectrometer; The test base is movably connected to a loading platform, which is composed of a loading box and a cover plate. A stepper motor is installed on the outside of the loading box, and a thrust rod is connected to the output shaft of the stepper motor. The inner end of the thrust rod is arranged in the loading box, and a two-point loading head is installed on the inner end of the thrust rod. A central loading head used in conjunction with the two-point loading head is also installed in the loading box. The central loading head is provided with an airflow control channel for controlling the humidity of the inner cavity of the loading box. A test sample is placed between the two-point loading head and the central loading head. A heating couple is also provided in the loading box. The cover plate is clamped on the loading box, and a cover glass is arranged in the middle of the cover plate. The Raman spectrometer is installed near the test base through an external bracket, and the lens group of the Raman spectrometer is arranged just above the cover glass.
[0007] As a further illustration of the present invention, a pressure sensor is installed between the thrust rod and the two-point loading head, and the stepping motor and the pressure sensor are respectively connected to a computer with a matching control system.
[0008] As a further illustration of the present invention, the airflow control channel is connected to an external humidity adjustment device through a pipeline, and the humidity adjustment device is also connected to a computer through a signal connection.
[0009] As a further explanation of the present invention, the airflow control channel is composed of a dry airflow channel and a wet airflow channel, and the humidity adjustment device is an adsorption dryer. The pressure swing adsorption principle is adopted to adjust the ratio of dry airflow and wet airflow in the airflow control channel through the adsorption dryer to achieve humidity adjustment.
[0010] As a further illustration of the present invention, the humidity in the loading box is controlled between 10% and 95%.
[0011] As a further illustration of the present invention, the thermocouple is used to complete the testing operation of the test sample within the range of 25°C-150°C.
[0012] As a further illustration of the present invention, the loading platform is movably mounted on the test base via a screw adjustment mechanism, and an adjustment knob for adjusting the lateral or longitudinal movement of the loading platform on the test base is also provided on the loading platform.
[0013] As a further illustration of the present invention, leveling feet are respectively installed at the four corners of the bottom surface of the test base, and the cover plate is specifically a glass plate.
[0014] In a second aspect, a multi-field loading in-situ collaborative characterization test method based on Raman spectroscopy comprises the following steps: First, place the test sample on the central loading head in the loading box, cover it with the cover plate, and adjust the lens group of the Raman spectrometer to be just above the cover glass; Then, the airflow control channel on the central loading head is used to control and adjust the humidity of the inner cavity of the loading box, and the temperature of the inner cavity of the loading box is adjusted using a thermocouple. After adjusting to the set humidity and temperature environmental conditions, the test sample state is balanced. The balance treatment time is 1 hour. After the humidity and temperature are balanced, with the two-point loading head unloaded, use the 10x lens of the lens group to perform a panoramic scan and select the area to be observed. After the area to be observed is adjusted to be clear, switch to the 50x lens of the lens group for observation and use the point scanning mode of the Raman spectrometer to perform the first scan; Then, the loading speed of the stepper motor is controlled and the thrust rod is used to drive the two-point loading head to load. After setting the loading time, the loading experiment begins. During the loading process, the test position is monitored in real time by the Raman spectrometer to keep the center point of the image at the observation point of the first scan. When the set loading time ends, the loading test of the test sample ends, the test data is saved, and the test analysis operation is completed.
[0015] As a further illustration of the present invention, the loading speed is 0.05-1 mm / min.
[0016] Compared with the prior art, the present invention has the following advantages: The present invention comprises a loading platform movably connected to a test base, a stepping motor is installed on the outside of a loading box, a thrust rod is connected to the output shaft of the stepping motor, the inner end of the thrust rod is arranged in the loading box, and a two-point loading head is installed on the inner end of the thrust rod, a central loading head used in conjunction with the two-point loading head is also installed in the loading box, an airflow control channel for controlling the humidity in the inner cavity of the loading box is provided on the central loading head, a test sample is placed between the two-point loading head and the central loading head, a heating couple is further provided in the loading box, a cover plate is clamped on the loading box, and a cover glass is provided in the middle of the cover plate, a Raman spectrometer is installed near the test base through an external bracket, and a lens group of the Raman spectrometer is arranged just above the cover glass, which can realize in-situ dynamic characterization of molecular configuration changes of macroscopic samples during bending / tensile stress transmission during temperature and humidity changes, and is convenient and practical. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 It is a side view of the overall structure of the present invention; Figure 3 It is a top view of the overall structure of the present invention; Figure 4 2 is a diagram of test results in an embodiment of the present invention.
[0018] Description of reference numerals: 1-test base; 11-leveling feet; 2-loading platform; 21-loading box; 22-cover plate; 23-cover glass; 24-adjustment knob; 3-stepper motor; 31-thrust rod; 32-pressure sensor; 4-two-point loading head; 5-center loading head; 6-airflow control channel; 7-thermocouple. DETAILED DESCRIPTION
[0019] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.
[0020] like Figure 1-3 As shown, the present invention provides a technical solution: a multi-field loading in-situ collaborative characterization test device based on Raman spectroscopy, comprising a test base 1, a loading platform 2, a stepper motor 3 and a Raman spectrometer; Among them, the test base 1 is movably connected to a loading platform 2, and the loading platform 2 is movably installed on the test base 1 through a screw adjustment mechanism. The screw adjustment mechanism is specifically an X-axis screw and a Y-axis screw used in the prior art. It is a prior art, and its detailed results and adjustment principles are not repeated here. The loading platform 2 is also provided with an adjustment knob 24 for adjusting the horizontal or vertical movement of the loading platform 2 on the test base 1. The direction of the X-axis and Y-axis of the loading platform 2 on the test base 1 can be adjusted by adjusting the knob 24.
[0021] The loading platform 2 consists of a loading box 21 and a cover plate 22. A stepper motor 3 is installed on the outside of the loading box 21. A thrust rod 31 is connected to the output shaft of the stepper motor 3. A pressure sensor 32 is also installed between the thrust rod 31 and the two-point loading head 4. The pressure sensor 32 is a 50kg pressure sensor. The stepper motor 3 and the pressure sensor 32 are respectively connected to a computer with a matching control system for completing the measurement of the loading pressure.
[0022] The inner end of the thrust rod 31 is disposed in the loading box 21, and a two-point loading head 4 is installed on the inner end of the thrust rod 31. A central loading head 5 for use with the two-point loading head 4 is also installed in the loading box 21, and a test sample is placed between the two-point loading head 4 and the central loading head 5. The central loading head 5 is provided with an air flow control channel 6 for controlling the humidity of the inner cavity of the loading box 21. The air flow control channel 6 is connected to an external humidity adjustment device through a pipeline, and the humidity adjustment device is also connected to the computer by signal. The air flow control channel 6 consists of a dry air flow channel and a wet air flow channel. The humidity adjustment device adopts the pressure swing adsorption principle to adjust the ratio of dry air flow and wet air flow in the air flow control channel 6 through an adsorption dryer to achieve humidity adjustment. The adsorption dryer is 220V, 15W, with a flow rate of 200L / min, an inlet temperature of ≤30°C, and air is supplied by an air pump. The ratio of air flow is adjusted by a gas flow controller with an operating temperature of -20-180°C and an operating pressure of ≤32MPa. The measuring range of the glass rotor flowmeter is 0-1.5L / min for adjustment. It is divided into a flow sensor, a diverter channel, a flow control valve, etc., which can automatically control the gas flow to achieve changes in humidity. The humidity in the loading box 21 is controlled between 10%-95%; A heating couple 7 is further provided in the loading box 21 , and the heating couple 7 is used to complete the testing operation of the test sample within the range of 25° C.-150° C.
[0023] The cover plate 22 is clamped on the loading box 21 , and a cover glass 23 is provided in the middle of the cover plate 22 . The Raman spectrometer is installed near the test base 1 through an external bracket, and the lens group of the Raman spectrometer is provided directly above the cover glass 23 .
[0024] Leveling feet 11 are respectively installed at the four corners of the bottom surface of the test base 1 for leveling the test base 1. The cover plate 22 is specifically a glass plate for easy observation.
[0025] The above-mentioned testing method of the multi-field loading in-situ collaborative characterization test device based on Raman spectroscopy includes the following steps: First, place the test sample on the central loading head 5 in the loading box 21, cover it with the cover plate 22, and adjust the lens group of the Raman spectrometer to be just above the cover glass 23; Then, the airflow control channel 6 on the central loading head 5 is used to control and adjust the humidity of the inner cavity of the loading box 21, and the thermocouple 7 is used to adjust the temperature of the inner cavity of the loading box 21. After adjusting to the set humidity and temperature environmental conditions, the test sample state is balanced. The balance treatment time is 1 hour; After the humidity and temperature are balanced, with the two-point loading head 4 unloaded, use the 10x lens of the lens group to perform a panoramic scan and select the area to be observed. After the area to be observed is adjusted to be clear, switch to the 50x lens of the lens group for observation, and use the point scanning mode of the Raman spectrometer to perform the first scan; the parameters used are: linearly polarized 785 nm laser or 532 nm laser, spectral measurement range 300-3000 cm -1The exposure time for a single acquisition was 5-20 seconds, and the number of cycles was 1-5. All subsequent scanning parameters remained unchanged, and the temperature fluctuation was kept within ±5°C and the humidity fluctuation was kept within ±5%.
[0026] Then, the loading speed of the stepper motor 3 is controlled and the thrust rod 31 is used to drive the two-point loading head 4 to load. The loading speed is 0.05-1 mm / min. After setting the loading time, the loading experiment begins. During the loading process, the test position is monitored in real time by the Raman spectrometer so that the center point of the image remains at the observation point of the first scan. At time n, another scan is performed. During the loading process, multiple time points can be selected for scanning. Each scan must ensure that the point scan position is consistent with the previous one to ensure the accuracy of the spectral frequency shift curve. When the set loading time ends, the loading test of the test sample is completed. Use the same parameters as the previous scan at the same position, save all the above Raman data and images, import the Raman data into the origin software, perform baseline calibration, and analyze the Raman peaks under different loads to observe their offset patterns.
[0027] Raman spectroscopy is used to study the micro-area distribution of natural cellulose by integrating the peak height, peak width or peak area of the characteristic peaks of cellulose molecules in the Raman spectrum to obtain a spectral imaging diagram, which can qualitatively study the spatial differences in cellulose concentration. When studying the distribution of plant cell wall components, the 345 to 390 cm -1 (β-D-glucose ring), 978 to 1178 cm -1 The Raman spectrum of bamboo is obtained at 1097 cm -1 The left and right are most obvious.
[0028] Figure 4 is the Raman spectrum, the horizontal axis is the wave number, and the vertical axis is the Raman intensity, such as Figure 4 The sample showed that at 1095 cm -1 There is a more obvious low-wavenumber motion at the α-axis, which is related to the stretching of the cellulose ring structure. During the whole process of stress relaxation, four time points were selected for analysis; When unloaded, the strain is 0 and the stress is 0 MPa; when stress relaxation reaches a constant displacement, the strain is 0.013 and the stress is 48 MPa; when stress relaxation ends, the strain is 0.013 and the stress is 46 MPa; and after the specimen is loaded to fracture, the strain is 0.015 and the stress is 24 MPa.
[0029] It can be seen from the figure that the positions of some spectral bands have changed, among which the 1097 cm -1As shown in the figure, as the stress increases, the sample is not loaded and reaches a constant displacement. When stress relaxation begins, the cellulose molecular chain is gradually stretched as the stress and strain increase. -1 The spectral band at 1097 cm moves to lower wavenumbers; when the stress relaxation of the sample ends, the strain remains unchanged during this process, and as the stress decreases, the spectral band at 1097 cm -1 The spectral band at 1097 cm moves to a higher wavenumber; then the sample is loaded until it breaks, the strain increases and the stress decreases, the cellulose molecules are broken, and the wavelength at 1097 cm -1 The spectral band at φ returned to its peak value when not loaded.
[0030] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.
[0031] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.
Claims
1. A multi-field loading in-situ collaborative characterization test device based on Raman spectroscopy, characterized by: include: Test base (1), loading platform (2), stepper motor (3) and Raman spectrometer; The test base (1) is movably connected to a loading platform (2), the loading platform (2) being composed of a loading box (21) and a cover (22), a stepper motor (3) being installed on the outside of the loading box (21), a thrust rod (31) being connected to the output shaft of the stepper motor (3), an inner end of the thrust rod (31) being arranged in the loading box (21), and a two-point loading head (4) being installed on the inner end of the thrust rod (31), a central loading head (5) being installed in the loading box (21) for use with the two-point loading head (4), an airflow control channel (6) being provided on the central loading head (5) for controlling the humidity of the inner cavity of the loading box (21), a test sample being placed between the two-point loading head (4) and the central loading head (5), and a heating couple (7) being provided in the loading box (21); The cover plate (22) is clamped on the loading box (21), and a cover glass (23) is provided in the middle of the cover plate (22). The Raman spectrometer is installed near the test base (1) through an external bracket, and the lens group of the Raman spectrometer is provided directly above the cover glass (23).
2. The multi-field loading in-situ collaborative characterization test device based on Raman spectroscopy according to claim 1, characterized in that: A pressure sensor (32) is also installed between the thrust rod (31) and the two-point loading head (4). The stepping motor (3) and the pressure sensor (32) are respectively connected to a computer with a matching control system.
3. The multi-field loading in-situ collaborative characterization test device based on Raman spectroscopy according to claim 1, characterized in that: The airflow control channel (6) is connected to an external humidity adjustment device through a pipeline, and the humidity adjustment device is also connected to the computer via a signal.
4. The multi-field loading in-situ collaborative characterization test device based on Raman spectroscopy according to claim 3, characterized in that: The airflow control channel (6) is composed of a dry airflow channel and a wet airflow channel, and the humidity adjustment device is an adsorption dryer. The pressure swing adsorption principle is adopted to adjust the ratio of dry airflow and wet airflow in the airflow control channel (6) through the adsorption dryer to achieve humidity adjustment.
5. The multi-field loading in-situ collaborative characterization test device based on Raman spectroscopy according to claim 4, characterized in that: The humidity in the loading box (21) is controlled between 10% and 95%.
6. The multi-field loading in-situ collaborative characterization test device based on Raman spectroscopy according to claim 1, characterized in that: The thermocouple (7) is used to complete the test operation of the test sample within the range of 25°C-150°C.
7. The multi-field loading in-situ collaborative characterization test device based on Raman spectroscopy according to claim 1, characterized in that: The loading platform (2) is movably mounted on the test base (1) via a screw adjustment mechanism, and an adjustment knob (24) is also provided on the loading platform (2) for adjusting the lateral movement or longitudinal movement of the loading platform (2) on the test base (1).
8. The multi-field loading in-situ collaborative characterization test device based on Raman spectroscopy according to claim 1, characterized in that: Leveling feet (11) are respectively installed at the four corners of the bottom surface of the test base (1), and the cover plate (22) is specifically a glass plate.
9. A multi-field loading in-situ collaborative characterization test method based on Raman spectroscopy, using the multi-field loading in-situ collaborative characterization test device based on Raman spectroscopy according to claim 1, characterized in that: The following steps are involved: First, place the test sample on the central loading head (5) in the loading box (21), cover it with the cover plate (22), and adjust the lens group of the Raman spectrometer to be set just above the cover glass (23); Then, the airflow control channel (6) on the central loading head (5) is used to control and adjust the humidity of the inner cavity of the loading box (21), and the temperature of the inner cavity of the loading box (21) is adjusted using the thermocouple (7). After adjusting to the set humidity and temperature environmental conditions, the test sample state is balanced, and the balance treatment time is 1 hour; After the humidity and temperature are balanced, in the unloaded state of the two-point loading head (4), a 10x lens of the lens group is used to perform a panoramic scan and select the area to be observed. After the area to be observed is adjusted to be clear, the 50x lens of the lens group is switched to observe, and the first scan is performed using the point scanning mode of the Raman spectrometer; Then, the loading speed of the stepper motor (3) is controlled and the thrust rod (31) is used to drive the two-point loading head (4) to load. After setting the loading time, the loading experiment is started. During the loading process, the test position is monitored in real time by the Raman spectrometer so that the center point of the image is kept at the observation point of the first scan; When the set loading time ends, the loading test of the test sample ends, the test data is saved, and the test analysis operation is completed.
10. The multi-field loading in-situ collaborative characterization test method based on Raman spectroscopy according to claim 9, characterized in that: The loading speed is 0.05-1 mm / min.