A multi-field loading in-situ cooperative characterization test device based on raman spectrum

Abstract

The utility model provides a kind of in-situ collaborative characterization testing device of multiple field loading based on Raman spectrum, the device includes test pedestal, loading platform, stepper motor and Raman spectrometer, and loading platform is movably connected on test pedestal, and the output shaft of the stepper motor of loading box body is connected with push rod, and two-point loading head is installed in the inside end of push rod, and center loading head is also installed in loading box body and cooperated with two-point loading head, and test sample is placed between two-point loading head and center loading head, and heating couple is also provided in loading box body, and Raman spectrometer is installed at the place close to test pedestal by external support, and the lens group of Raman spectrometer is arranged at the place directly above cover glass. The utility model can realize in-situ dynamic characterization of molecular configuration change of macroscopic sample in bending / tensile stress transmission process in the process of temperature and humidity change, and it is convenient and practical.

Description

Technical Field

[0001] This invention belongs to the field of spectromechanics technology, specifically relating to a multi-field loading in-situ collaborative characterization and testing device based on Raman spectroscopy. Background Technology

[0002] Multi-scale in-situ characterization of heterogeneous hierarchical materials under multi-field coupling conditions has always been challenging. Constructing a systematic characterization technique from macroscopic to microscopic levels is of great significance for achieving quantitative description at the molecular scale and can lead to important breakthroughs in fundamental theoretical research. Currently, spectromechanical measurement and analysis techniques are developing rapidly and are beginning to be used in various materials fields. Among them, micro Raman spectroscopy is easy to couple with mechanical or other instruments and is 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 thoroughly studied, and this testing device is still lacking.

[0004] Based on this, a multi-field loading in-situ synergistic characterization and testing device based on Raman spectroscopy is proposed, which is suitable for multi-field loading in-situ synergistic characterization and testing of biomass materials such as bamboo and wood. Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide a multi-field loading in-situ collaborative characterization and testing device based on Raman spectroscopy to address the shortcomings of the prior art and solve the problems mentioned in the background art.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows: In the first aspect, a multi-field loading in-situ collaborative characterization and testing 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 consists of a loading chamber and a cover plate. A stepper motor is installed on the outside of the loading chamber, and a thrust rod is connected to the output shaft of the stepper motor. The inner end of the thrust rod is located inside the loading chamber, and a two-point loading head is installed on the inner end of the thrust rod. A central loading head that works with the two-point loading head is also installed inside the loading chamber. The central loading head is provided with an airflow control channel for controlling the humidity inside the loading chamber. A test sample is placed between the two-point loading head and the central loading head. A heating coupler is also provided inside the loading chamber. The cover plate is snapped onto the loading box, and a cover glass is placed in the middle of the cover plate. The Raman spectrometer is mounted near the test base by an external bracket, and the lens group of the Raman spectrometer is positioned directly above the cover glass.

[0007] As a further explanation of this utility model, a pressure sensor is also installed between the thrust rod and the two-point loading head, and the stepper motor and the pressure sensor are respectively connected to a computer with a matching control system.

[0008] As a further explanation of this utility model, 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 via a signal connection.

[0009] As a further explanation of this utility model, the airflow control channel consists of a dry airflow channel and a wet airflow channel. The humidity adjustment device is an adsorption dryer. The humidity is adjusted by using the pressure swing adsorption principle to regulate the ratio of dry airflow and wet airflow in the airflow control channel through the adsorption dryer.

[0010] As a further explanation of this utility model, the humidity inside the loading box is controlled between 10% and 95%.

[0011] As a further explanation of this utility model, the heating coupler is used to complete the testing of the test sample within the range of 25℃-150℃.

[0012] As a further explanation of this utility model, the loading platform is movably mounted on the test base via a lead screw adjustment mechanism, and the loading platform is also provided with an adjustment knob for adjusting the lateral or longitudinal movement of the loading platform on the test base.

[0013] As a further explanation of this utility model, leveling feet are installed at the four corners of the bottom surface of the test base, and the cover plate is specifically a glass plate.

[0014] As a further explanation of this utility model, the loading speed is 0.05-1 mm / min.

[0015] This utility model has the following advantages compared with the prior art: This invention features a loading platform movably connected to a test base. A stepper motor is mounted on the outside of the loading chamber, and a thrust rod is connected to the output shaft of the stepper motor. The inner end of the thrust rod is located inside the loading chamber, and a two-point loading head is mounted on the inner end of the thrust rod. A central loading head, which works in conjunction with the two-point loading head, is also installed inside the loading chamber. The central loading head has an airflow control channel for controlling the humidity inside the loading chamber. A test sample is placed between the two-point loading head and the central loading head. A heating couple is also installed inside the loading chamber. A cover plate is snapped onto the loading chamber, and a cover glass is placed in the middle of the cover plate. A Raman spectrometer is mounted near the test base via an external bracket, with the lens assembly of the Raman spectrometer positioned directly above the cover glass. This invention enables in-situ dynamic characterization of changes in molecular configuration of macroscopic samples during bending / tensile stress transmission under varying temperature and humidity conditions, making it convenient and practical. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a side view of the overall structure of this utility model; Figure 3 This is a top view of the overall structure of this utility model; Figure 4 This is a test result diagram from an embodiment of this utility model.

[0017] Explanation of reference numerals in the attached figures: 1-Test base; 11-Leveling support; 2-Loading platform; 21-Loading box; 22-Cover plate; 23-Cover glass slide; 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-Heating coupler. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0019] like Figure 1-3 As shown, this utility model provides a technical solution: a multi-field loading in-situ collaborative characterization and testing device based on Raman spectroscopy, including a test base 1, a loading platform 2, a stepper motor 3, and a Raman spectrometer; The test base 1 is movably connected to a loading platform 2, which is movably mounted on the test base 1 via a lead screw adjustment mechanism. The lead screw adjustment mechanism is specifically an X-axis lead screw and a Y-axis lead screw used in the prior art, which is existing technology, and its detailed results and adjustment principle will not be described 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 loading platform 2 on the X-axis and Y-axis on the test base 1 can be adjusted by adjusting the knob 24.

[0020] 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 push rod 31 is connected to the output shaft of the stepper motor 3. A pressure sensor 32 is also installed between the push 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 to measure the loading pressure.

[0021] The inner end of the thrust rod 31 is set inside the loading box 21, and a two-point loading head 4 is installed on the inner end of the thrust rod 31. A center loading head 5 that works with the two-point loading head 4 is also installed inside the loading box 21. A test sample is placed between the two-point loading head 4 and the center loading head 5. The central loading head 5 is equipped with an airflow control channel 6 for controlling the humidity inside the loading chamber 21. The airflow control channel 6 is connected to an external humidity adjustment device via a pipeline. The humidity adjustment device is also connected to a computer via a signal. The airflow control channel 6 consists of a dry airflow channel and a wet airflow channel. The humidity adjustment device uses the pressure swing adsorption principle to adjust the ratio of dry airflow and wet airflow in the airflow control channel 6 through an adsorption dryer to achieve humidity adjustment. The adsorption dryer is 220V, 15W, with a flow rate of 200L / min and an inlet temperature ≤30℃. It is supplied with air by a gas pump. The airflow ratio is adjusted by a gas flow controller with an operating temperature of -20-180℃ and an operating pressure ≤32MPa. The glass rotor flow meter has a measurement range of 0-1.5L / min and is composed of a flow sensor, a flow divider channel, and a flow regulating valve. It can automatically control the gas flow to achieve humidity changes, and the humidity inside the loading chamber 21 is controlled between 10% and 95%. The loading chamber 21 is also equipped with a heating coupler 7, which is used to complete the testing of the test sample in the range of 25℃-150℃.

[0022] The cover plate 22 is snapped onto the loading box 21, and a cover glass 23 is provided in the middle of the cover plate 22. The Raman spectrometer is mounted near the test base 1 by an external bracket, and the lens group of the Raman spectrometer is located directly above the cover glass 23.

[0023] The test base 1 is equipped with leveling feet 11 at the four corners of its bottom surface for leveling the test base 1. The cover plate 22 is a glass plate for easy observation.

[0024] The testing method of the above-mentioned multi-field loading in-situ synergistic characterization testing device based on Raman spectroscopy includes the following steps: First, place the test sample in the center of the loading head 5 inside the loading chamber 21, cover it with the cover plate 22, and adjust the lens group of the Raman spectrometer to be positioned directly above the cover glass 23. Then, the humidity inside the loading chamber 21 is controlled and adjusted by the airflow control channel 6 on the central loading head 5, and the temperature inside the loading chamber 21 is adjusted by the heating coupler 7. After adjusting to the set humidity and temperature environment conditions, the test sample state is balanced, and the balancing time is 1 hour. After humidity and temperature have balanced, with the two-point loading head 4 unloaded, a panoramic scan is performed using the 10x lens of the lens assembly to select the area to be observed. Once the area is clear, the zoom level is switched to the 50x lens of the lens assembly for observation. The first scan is performed using the spot scan mode of the Raman spectrometer. The parameters used are: a linearly polarized 785 nm laser or a 532 nm laser, and a spectral measurement range of 300–3000 cm⁻¹. -1 The single-scan exposure time is 5-20 seconds, and the number of cycles is 1-5. All subsequent scanning parameters remain unchanged, and the temperature fluctuation is maintained at ±5℃ and the humidity fluctuation at ±5% throughout the process.

[0025] Then, the loading speed of the stepper motor 3 is controlled and the two-point loading head 4 is driven by the push rod 31 to perform loading. The loading speed is 0.05-1 mm / min. 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 to keep the center point of the image at the observation point of the first scan. When the time is n, the scan is performed again. During the loading process, multiple time points can be selected for scanning. Each scan must ensure that the position of the point scan is consistent with the previous one to ensure the accuracy of the spectral frequency shift curve. After the set loading time ends, the loading test of the test sample is completed. Using the same parameters as before, a second scan is performed at the same location. All the Raman data and images are saved. The Raman data is imported into Origin software for baseline calibration and analysis of the Raman peak values ​​under different loads to observe the shift pattern.

[0026] Raman spectroscopy is used to study the micro-regional distribution of natural cellulose by integrating the peak height, peak width, or peak area of ​​characteristic peaks of cellulose molecules in the Raman spectrum to obtain a spectral image, thus qualitatively studying the spatial differences in cellulose concentration. When studying the distribution of plant cell wall components, the 345 to 390 cm⁻¹ region can be analyzed. -1 (β-D-glucose ring), 978 to 1178 cm -1 Raman spectroscopy in the (COC) wavenumber region yielded images of the spatial distribution of cellulose. The Raman spectrum of bamboo was obtained at 1097 cm⁻¹. -1 The left and right sides are the most obvious.

[0027] Figure 4 The image shows a Raman spectrum, with wavenumber on the horizontal axis and Raman intensity on the vertical axis. Figure 4 The sample was observed to be at 1095 cm⁻¹. -1 There was a noticeable low-wavenumber motion, which is related to the stretching of the cellulose ring structure. Four time points were selected for analysis throughout the stress relaxation process. When unloaded, the strain is 0 and the stress is 0 MPa; when the stress relaxation reaches a constant displacement, the strain is 0.013 and the stress is 48 MPa; when the 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.

[0028] The figure shows that the positions of some spectral bands have changed, including the 1097 cm⁻¹ band in the Raman spectrum. -1 The changes are most significant at the [location name]. As shown in the figure, with the increase of stress, from unloaded to the start of stress relaxation at a constant displacement, the cellulose molecular chains are gradually stretched with increasing stress and strain, reaching 1097 cm [unit value]. -1 The spectral band at 1097 cm⁻¹ shifts to lower wavenumbers; when the stress relaxation of the sample ends, the strain remains constant during this process, and as the stress decreases, the strain at 1097 cm⁻¹... -1 The spectral band shifts to higher wavenumbers; then the sample is further loaded until fracture, strain increases and stress decreases, cellulose molecules are broken, 1097 cm⁻¹ -1 The spectral band at that location recovered to its peak value when unloaded.

[0029] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0030] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A multi-field loading in-situ synergistic characterization and testing device based on Raman spectroscopy, characterized in that: 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), which 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), and a push rod (31) is connected to the output shaft of the stepper motor (3). The inner end of the push rod (31) is located inside the loading box (21), and a two-point loading head (4) is installed on the inner end of the push rod (31). A center loading head (5) is also installed inside the loading box (21) to cooperate with the two-point loading head (4). An airflow control channel (6) for controlling the humidity inside the loading box (21) is provided on the center loading head (5). A test sample is placed between the two-point loading head (4) and the center loading head (5). A heating coupler (7) is also provided inside the loading box (21). The cover plate (22) is snapped onto 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) by an external bracket, and the lens group of the Raman spectrometer is located directly above the cover glass (23). 2.The Raman spectrum based multi-field loading in-situ synergic characterization testing device 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 stepper motor (3) and the pressure sensor (32) are respectively connected to a computer with a matching control system. 3.The Raman spectroscopy based multi-field loading in-situ synergic characterization testing device according to claim 1, characterized in that, The airflow control channel (6) is connected to an external humidity adjustment device via a pipeline, and the humidity adjustment device is also connected to a computer via a signal.

4. The multi-field loading in-situ synergic characterization test device based on Raman spectrum according to claim 3, characterized in that, The airflow control channel (6) consists of a dry airflow channel and a wet airflow channel. The humidity adjustment device is an adsorption dryer. The humidity is adjusted by using the pressure swing adsorption principle to adjust the ratio of dry airflow and wet airflow in the airflow control channel (6).

5. The multi-field loading in-situ synergic characterization test device based on Raman spectrum according to claim 4, characterized in that, The humidity inside the loading chamber (21) is controlled between 10% and 95%.

6. The multi-field loading in-situ synergic characterization test device based on Raman spectrum according to claim 1, characterized in that, The heating coupler (7) is used to complete the testing of the test sample in the range of 25℃-150℃. 7.The Raman spectroscopy based multi-field loading in-situ synergic characterization testing device according to claim 1, characterized in that, The loading platform (2) is movably mounted on the test base (1) via a lead screw adjustment mechanism. 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).

8. The multi-field loading in-situ synergic characterization test device based on Raman spectrum according to claim 1, characterized in that, The test base (1) is equipped with leveling feet (11) at the four corners of its bottom surface, and the cover plate (22) is a glass plate.

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