Photoelastic-infrared-based full-field stress synchronous test experiment system and photoelastic-infrared-based full-field stress synchronous test experiment method

Abstract

The invention discloses a photoelastic-infrared-based full-field stress synchronous test experiment system and method, and belongs to the technical field of mechanical test. According to the system, an intelligent photoelastic test system is used for acquiring optical interference fringes generated by stress on the surface, attached with a photoelastic material, of a test piece in real time by using a photoelastic test method; the infrared test system is used for acquiring the temperature change of the opposite surface of the test piece pasted with the photoelastic material due to stress in real time by utilizing an infrared thermal imaging test method; the synchronous control system is used for controlling the change frequency of the optical axis position and the fast axis position in the optical lens, the frequency of optical interference fringes collected by the high-speed CMOS camera, the frequency of load application and the infrared thermal image collection frequency. Synchronous testing of a dynamic real-time photoelastic method and an infrared high-speed thermal imaging related method and high-precision real-time full-field stress automatic analysis can be achieved, the advantages of the two methods are combined, and full-field stress distribution and evolution conditions of rock solid material test pieces are visually detected through experiments.

Description

Technical Field

[0001] The present invention relates to the technical field of mechanical testing, and in particular to a full-field stress synchronous testing experimental system and method based on photoelasticity-infrared. Background Art

[0002] At present, in the mechanical experimental determination of loaded objects, commonly used experimental techniques include strain gauges and acoustic emission, etc., but these experimental techniques are difficult to detect the full-field stress distribution and evolution characteristics. Photoelastic testing, as a classic mechanical testing method, is widely used in mechanical analysis because of its full-field and real-time characteristics. With the advancement of technology, the types of materials with temporary birefringence properties are increasing, and models can be made for different engineering backgrounds according to different material properties for experiments. However, photoelastic testing is limited to transparent materials, and mechanical experimental determination cannot be performed on non-transparent materials. In addition, photoelastic testing is also limited by the constant angle of the optical mirror in the optical path. Therefore, it is difficult to use the photoelastic testing method to distinguish the optical interference fringes generated by the force on the surface of the loaded object in real time, resulting in unclear mechanical properties of the loaded object. Summary of the invention

[0003] In order to solve the problems existing in the prior art, the present invention provides the following technical solutions.

[0004] The first aspect of the present invention provides a full-field stress synchronous test experimental system based on photoelasticity and infrared, comprising: an intelligent photoelasticity test system, an infrared test system, a specimen loading system and a synchronous control system;

[0005] The specimen loading system is used to apply a load to the specimen, the specimen is a non-transparent rock-like solid material, and a photoelastic patch material with similar mechanical properties is attached to the surface;

[0006] The intelligent photoelastic testing system is used to obtain the optical interference fringes generated by the force on the surface of the test piece with the photoelastic patch material in real time by using the photoelastic testing method, and then obtain the full-field stress distribution and the fringes evolution process with the stress change;

[0007] The infrared testing system is used to obtain the temperature change of the opposite side of the test piece with the photoelastic patch material attached due to the force in real time by using the infrared thermal imaging testing method, and then obtain the full-field stress distribution and evolution process;

[0008] The synchronous control system is used to control the optical axis position of the polarizer and the analyzer in the intelligent photoelastic testing system and the rotation frequency of the fast axis position of the first quarter wave plate and the second quarter wave plate, the frequency of the high-speed CMOS camera collecting optical interference fringes, the frequency of the specimen loading system applying load to the specimen, and the infrared thermal imaging collection frequency of the infrared testing system.

[0009] Preferably, the synchronous control system is controlled by the following method: each time the specimen loading system applies a load to the specimen, the optical axis positions of the polarizer and the analyzer and the fast axis positions of the first quarter wave plate and the second quarter wave plate in the intelligent photoelastic testing system rotate five times, the corresponding high-speed CMOS camera collects optical interference fringes five times, and the infrared thermal imaging of the infrared testing system collects once.

[0010] Preferably, rotating the optical axis positions of the polarizer and the analyzer and the fast axis positions of the first quarter wave plate and the second quarter wave plate in the intelligent photoelastic testing system five times comprises: rotating according to the angles in the following table;

[0011] α i 6 c π / 2 π / 2 0 0 5π / 8 5π / 8 π / 8 π / 8 3π / 4 3π / 4 π / 4 π / 4 7π / 8 7π / 8 3π / 8 3π / 8 π / 2 3π / 4 π / 4 0

[0012] Wherein, α represents the angle of rotation of the optical axis of the polarizer from the x-axis, θ represents the angle of rotation of the fast axis of the first quarter wave plate from the x-axis, β represents the angle of rotation of the optical axis of the analyzer from the x-axis, and γ represents the angle of rotation of the fast axis of the second quarter wave plate from the x-axis.

[0013] Preferably, the specimen loading system includes a loading device and a loading control system, the loading device is provided with a clamp, and a specimen of non-transparent rock-like solid material with a photoelastic patch material attached to the surface is mounted on the clamp, and the loading control system is used to control the loading device to apply a load to the specimen through the clamp; the synchronous control system controls the frequency with which the loading control system applies a load to the specimen.

[0014] Preferably, the intelligent photoelastic testing system includes a photoelastic testing optical path, a high-speed CMOS camera, a photoelastic image analysis system, a first controller, a second controller and a third controller; a white light source, a filter, a polarizer, a first quarter wave plate, a beam expander, a convex lens, a second quarter wave plate, an analyzer and a collimator are sequentially arranged along the photoelastic testing optical path; the high-speed CMOS camera is used to receive the optical signal of the collimator and output a photoelastic interference image according to the optical signal and send it to the photoelastic image analysis system; the photoelastic image analysis system is used to calculate and analyze the full-field stress distribution of the specimen and the fringe evolution process with stress change using the photoelastic interference image; the first controller is used to control the optical axis position of the polarizer and the analyzer; the second controller is used to control the fast axis position of the first quarter wave plate and the second quarter wave plate; the third controller is used to control the start and end of the filter; the specimen is located between the beam expander and the convex lens, so that the light beam output by the beam expander covers the specimen and is reflected to the convex lens.

[0015] The second aspect of the present invention provides a photoelastic-infrared based full-field stress synchronous test experimental method, using the photoelastic-infrared based full-field stress synchronous test experimental system as described in the first aspect, the method comprises:

[0016] Step 1, the specimen loading system applies a load to the specimen;

[0017] Step 2, turn on the white light source, the white light is incident on the filter, the unfiltered white light is incident on the polarizer and converted into plane polarized light and then enters the first quarter wave plate, the generated circularly polarized light is incident on the beam expander, the light beam output by the beam expander covers the test piece and is reflected from the test piece to the convex lens, passes through the convex lens, passes through the second quarter wave plate and the analyzer, and enters the collimator, and finally the high-speed CMOS camera receives the light signal from the collimator and outputs the photoelastic interference image according to the light signal and sends it to the photoelastic image analysis system; at the same time, the optical axis positions of the polarizer and the analyzer are controlled by the first controller, and the fast axis positions of the first quarter wave plate and the second quarter wave plate are controlled by the second controller; the full-field equal inclination angle data are obtained;

[0018] Step 3, start the third controller to filter the white light incident into the filter into monochromatic light, so that the monochromatic light is incident into the polarizer, and the subsequent method is the same as step 2; obtain full-field equidistant line data;

[0019] Step 4, calculating the full-field stress according to the full-field isopiped data and the full-field iso-difference line data;

[0020] Step 5, repeat steps 1 to 4 to obtain the full-field stress under different loads and the evolution process with stress change;

[0021] Step 6, using the infrared testing system and infrared thermal imaging testing method to obtain in real time the temperature change of the opposite side of the test piece with the photoelastic patch material attached thereto due to the force, and then obtain the full-field stress distribution and evolution process;

[0022] There is no particular order for steps 5 and 6.

[0023] Preferably, the experiments are conducted in a constant temperature and humidity experimental environment.

[0024] Preferably, before step 1, the temperature of the surface of the specimen is observed by an infrared thermal imager, and the experiment is started when the temperature of the surface of the specimen is uniform.

[0025] Preferably, the use of the first controller to control the optical axis positions of the polarizer and the analyzer, and the use of the second controller to control the fast axis positions of the first quarter wave plate and the second quarter wave plate include: each time the specimen loading system applies a load to the specimen, the optical axis positions of the polarizer and the analyzer and the fast axis positions of the first quarter wave plate and the second quarter wave plate are rotated five times, the corresponding high-speed CMOS camera collects optical interference fringes five times, and the infrared thermal imaging of the infrared testing system is collected once.

[0026] Preferably, rotating the optical axis positions of the polarizer and the analyzer and the fast axis positions of the first quarter wave plate and the second quarter wave plate five times comprises: rotating according to the angles in the following table;

[0027]

[0028]

[0029] Wherein, α represents the angle of rotation of the optical axis of the polarizer from the x-axis, θ represents the angle of rotation of the fast axis of the first quarter wave plate from the x-axis, β represents the angle of rotation of the optical axis of the analyzer from the x-axis, and γ represents the angle of rotation of the fast axis of the second quarter wave plate from the x-axis.

[0030] The beneficial effects of the present invention are as follows: the present invention provides a photoelastic-infrared-based full-field stress synchronous testing experimental system and method, which can realize the synchronous testing of dynamic real-time intelligent photoelastic methods and infrared high-speed thermal imaging related methods, and automatically collect data of the two experimental methods at the same time, thereby improving the reliability of the experiment; it can also realize high-precision real-time full-field stress automatic analysis, and can combine the advantages of the two methods, and intuitively detect the full-field stress distribution and changes of the rock specimen through experimental technology, and conduct specific analysis of local stress and strain. It breaks the limitation of transparent materials in photoelastic tests, and can also be applied to dynamic loading processes, improving the accuracy of stress calculation. In addition, the entire experimental process can be synchronously controlled, synchronously tested and recorded. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic structural diagram of a photoelastic-infrared based full-field stress synchronous testing experimental system according to the present invention;

[0032] The meanings of the symbols in the figure are as follows:

[0033] 1. White light source, 2. Filter, 3. Polarizer, 4. First quarter wave plate, 5. Beam expander, 6. Convex lens, 7. Second quarter wave plate, 8. Analyzer, 9. Collimator, 10. High-speed CMOS camera, 11. Loading device, 12. Fixture, 13. Test piece, 14. Photoelastic patch material, 15. First controller, 16. Second controller, 17. Photoelastic image analysis system, 18. Infrared high-speed camera, 19. Infrared image analysis system, 20. Loading control system, 21. Synchronous control system, 22. Third controller. DETAILED DESCRIPTION

[0034] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0035] Embodiment 1

[0036] like Figure 1 As shown, an embodiment of the present invention provides a full-field stress synchronous test experimental system based on photoelasticity and infrared, including: an intelligent photoelasticity test system, an infrared test system, a specimen loading system and a synchronous control system; the specimen loading system is used to apply a load to the specimen, the specimen is a non-transparent rock-like solid material, and a photoelastic patch material with similar mechanical properties is attached to the surface; the intelligent photoelasticity test system is used to use a photoelasticity test method to obtain in real time the optical interference fringes generated by the force on the surface of the specimen with the photoelastic patch material attached, and then obtain the full-field stress distribution and the fringes evolution process with the stress change; the infrared test system is used to use an infrared thermal imaging test method to obtain in real time the temperature change of the opposite surface of the specimen with the photoelastic patch material attached due to the force, and then obtain the full-field stress distribution and evolution process; the synchronous control system is used to control the optical axis position of the polarizer and the analyzer in the intelligent photoelasticity test system and the change frequency of the fast axis position of the first quarter wave plate and the second quarter wave plate, the frequency of the high-speed CMOS camera collecting optical interference fringes, the frequency of the specimen loading system applying load to the specimen and the infrared thermal imaging acquisition frequency of the infrared test system.

[0037] The specimen loading system may include a loading device 11 and a loading control system 20, wherein the loading device 11 is provided with a fixture 12, and a specimen 13 of a non-transparent rock-like solid material with a photoelastic patch material 14 attached to the surface is mounted on the fixture 12, and the loading control system 20 is used to control the loading device 11 to apply a load to the specimen 13 through the fixture 12; the synchronous control system 21 controls the frequency at which the loading control system 20 applies a load to the specimen 13. The loading rate can be set by the loading control system to control the loading of stress and strain.

[0038] The intelligent photoelastic test system comprises a photoelastic test optical path, a high-speed CMOS camera, a photoelastic image analysis system, a first controller, a second controller and a third controller; along the photoelastic test optical path, there are arranged in sequence: a white light source 1, a filter 2, a polarizer 3, a first quarter-wave plate 4, a beam expander 5, a convex lens 6, a second quarter-wave plate 7, an analyzer 8 and a collimator 9; the high-speed CMOS camera 10 is used to receive the optical signal of the collimator and output a photoelastic interference image according to the optical signal and send it to the photoelastic image analysis system 17; the optical The photoelastic image analysis system 17 is used to calculate and analyze the full-field stress distribution of the specimen and the fringe evolution process with stress changes by using the photoelastic interference image; the first controller 15 is used to control the optical axis position of the polarizer 3 and the analyzer 8; the second controller 16 is used to control the fast axis position of the first quarter wave plate 4 and the second quarter wave plate 7; the third controller 22 is used to control the start and end of the filter 2; the specimen 13 is located between the beam expander 5 and the convex lens 6, so that the light beam output by the beam expander 5 covers the specimen 13 and is reflected to the convex lens 6.

[0039] In the embodiment of the present invention, the white light source adopts a high-power, high-intensity white light source so that interference occurs on the surface of the specimen later. The filter can allow certain wavelengths of light to pass through while blocking other wavelengths of light. In the present invention, it is used to filter out other light waves in white light to form monochromatic light. The polarizer can convert white light into plane polarized light, one of which is completely absorbed and the other propagates forward along a fixed plane. The first quarter-wave plate is used to convert plane polarized light into circularly polarized light. The beam expander can expand the input beam diameter to a larger output beam diameter. By expanding the beam, the divergence angle of the beam will be reduced accordingly, making the beam more collimated. The convex lens is used to converge the divergent light. The second quarter-wave plate is used to convert circularly polarized light into plane polarized light. The analyzer can synthesize all light vectors in a plane into a new light vector for analysis. The collimator can convert the light beam into parallel light or quasi-parallel light. By ensuring that the light propagates parallel to each other, the light can be prevented from diffusing to unnecessary directions, thereby improving the accuracy and efficiency of the optical system. High-speed CMOS cameras can record photoelastic images at a rate of 100,000 frames per second to match the rate at which the specimen is loaded, and can capture clear, high-resolution images even in low-light environments. Ultra-high-speed CMOS cameras convert optical signals into electrical signals through CMOS image sensors, and then convert analog signals into digital signals through analog-to-digital converters (ADCs), and finally transmit data to computers or dedicated image processing systems for processing and analysis through high-speed interfaces (such as CameraLink, USB 3.0, etc.). The loading device can apply load to the specimen through a fixture. Before the test begins, the specimen is fixedly installed between the upper and lower fixtures. The specimen is a non-transparent rock-like solid material with a photoelastic patch material attached to the surface. The rock specimen can adopt the standard uniaxial compression specimen size, with a photoelastic patch material attached to one side and the other side finely polished with sandpaper to ensure that there are no obvious holes and cracks on its surface. A photoelastic patch material with birefringence properties similar to the mechanical properties of a rock specimen (such as compressive strength, tensile strength, elastic modulus, Poisson's ratio and other parameters) can be prepared to ensure that the size of the photoelastic patch material can completely fit the surface of the rock specimen. The first controller can be used to control the optical axis position of the polarizer and the analyzer. When in use, a preset module can be added to the first controller to change the angle of rotation of the optical axis of the polarizer and the analyzer from the x-axis, that is, α and β. The second controller is used to control the fast axis position of the first quarter wave plate and the second quarter wave plate. When in use, a preset module can be added to the second controller to change the angle of rotation of the fast axis of the first quarter wave plate and the second quarter wave plate from the x-axis, that is, θ and γ. Every time α, β, γ and θ are changed, a high-speed CMOS camera records a photoelastic interference image at a rate of 100,000 frames per second. The photoelastic image analysis system receives all the photoelastic interference images and obtains the full-field stress distribution of the specimen and the fringe evolution process with stress change according to a certain mechanical calculation method based on these photoelastic interference images.

[0040] The present invention has found that the deformation process of an object is often accompanied by a change in energy. Infrared thermal imagers can detect the temperature distribution on the surface of an object in real time and non-destructively, thereby reflecting the mechanical properties of the material surface. Therefore, the present invention combines two testing technologies, infrared and photoelastic, to reflect the full-field stress distribution and evolution of the loaded rock from the perspectives of thermal and mechanical. Among them, the infrared testing system is used to obtain the energy change caused by the force on the opposite side of the specimen with the photoelastic patch material. The infrared testing system includes an infrared high-speed camera 18 and an infrared image analysis system 19. Each time the infrared high-speed camera 18 takes an infrared image, it is transmitted to the infrared image analysis system 19 for image processing to calculate the full-field stress distribution. With the increase of force and the increase of the number of acquisitions, more and more infrared images are obtained, thereby reflecting the full-field stress evolution process through infrared mechanical images. The working principle of the infrared high-speed camera is mainly based on the detection and conversion of infrared radiation. The object itself emits infrared radiation, and the infrared high-speed camera captures these infrared rays through the special photosensitive elements and optical systems inside and converts them into electronic signals. These electronic signals are then processed and converted to form visible images. The infrared high-speed camera has an acquisition frequency of up to 1,000 frames per second, which can match the acquisition frequency of the pressure sensor. It has high sensitivity and can capture weak infrared signals, monitor the target in real time and take images, and promptly detect changes and abnormalities in the target. The working principle of the infrared image analysis system is mainly based on the detection and conversion of infrared radiation. When the temperature of an object is higher than absolute zero, it will emit infrared radiation. The infrared image analysis system receives these radiations through the detector in the infrared high-speed camera and converts them into electrical signals. After image processing such as amplification, filtering and denoising, the electrical signals are converted into temperature images. Finally, the temperature image is analyzed and calculated by the image analysis software and converted into full-field mechanical information.

[0041] In the present invention, the synchronous control system can realize the synchronous control of the loading system, the intelligent photoelastic test system, the high-speed CMOS camera and the infrared test system. For example, every time the specimen loading system applies a load to the specimen, the optical axis positions of the polarizer and the analyzer in the intelligent photoelastic test system and the fast axis positions of the first quarter wave plate and the second quarter wave plate are rotated five times, the corresponding high-speed CMOS camera collects optical interference fringes five times, and the infrared thermal imaging of the infrared test system is collected once.

[0042] In a preferred embodiment of the present invention, rotating the optical axis positions of the polarizer and analyzer and the fast axis positions of the first quarter wave plate and the second quarter wave plate in the intelligent photoelastic testing system five times includes: rotating according to the angles in the following table.

[0043]

[0044]

[0045] Wherein, α represents the angle of rotation of the optical axis of the polarizer from the x-axis, θ represents the angle of rotation of the fast axis of the first quarter wave plate from the x-axis, β represents the angle of rotation of the optical axis of the analyzer from the x-axis, and γ represents the angle of rotation of the fast axis of the second quarter wave plate from the x-axis.

[0046] Each time a load is applied to the specimen, the first controller and the second controller rotate α, θ, β and γ five times simultaneously, and the corresponding optical interference fringes are collected by a high-speed CMOS camera each time. After collecting five times, a stress value is calculated. At the same time, the infrared test system records the infrared thermal imaging results of the specimen surface through an infrared high-speed camera, and then calculates a stress value.

[0047] Therefore, the technical solution provided by the present invention can realize synchronous testing and recording of the entire experimental process through signals and synchronous control. At the same time, it can realize the synchronous testing of dynamic real-time intelligent photoelastic method and infrared high-speed thermal imaging related methods, realize the loading of rock specimens with different loading modes and different loading rates, and can automatically start collecting data of the two experimental methods at the same time, and can compare the data obtained by the two experimental methods, thereby improving the reliability of the experiment, realizing high-precision real-time full-field stress automatic analysis, and combining the advantages of the two methods. Through experimental technology, the full-field stress distribution and changes of the rock specimen can be intuitively detected, and the local stress and strain are specifically analyzed. Compared with a single measurement method, the present invention combines the photoelastic test method and the infrared thermal imaging test method, which not only provides more analysis content for full-field stress and strain measurement, but also breaks the limitation of transparent materials in photoelastic tests, and can also be applied to dynamic loading processes, improving the accuracy of stress calculation. In the specific application process, the loading method can be changed according to the experimental requirements, such as pendulum impact loading or Hopkinson bar loading, and the specimen can also be replaced. Therefore, the present invention provides a new method for full-field stress and strain measurement.

[0048] Embodiment 2

[0049] The embodiment of the present invention provides a full-field stress synchronization test experimental method based on photoelasticity and infrared, using the full-field stress synchronization test experimental system based on photoelasticity and infrared as described in Example 1, the method includes:

[0050] Step 1, the specimen loading system applies a load to the specimen;

[0051] Step 2, turn on the white light source, the white light is incident on the filter, the unfiltered white light is incident on the polarizer and converted into plane polarized light and then enters the first quarter wave plate, the generated circularly polarized light is incident on the beam expander, the light beam output by the beam expander covers the test piece and is reflected from the test piece to the convex lens, passes through the convex lens, passes through the second quarter wave plate and the analyzer, and enters the collimator, and finally the high-speed CMOS camera receives the light signal from the collimator and outputs the photoelastic interference image according to the light signal and sends it to the photoelastic image analysis system; at the same time, the optical axis positions of the polarizer and the analyzer are controlled by the first controller, and the fast axis positions of the first quarter wave plate and the second quarter wave plate are controlled by the second controller; the full-field equal inclination angle data are obtained;

[0052] Step 3, start the third controller to filter the white light incident into the filter into monochromatic light, so that the monochromatic light is incident into the polarizer, and the subsequent method is the same as step 2; obtain full-field equidistant line data;

[0053] Step 4, calculating the full-field stress according to the full-field isopiped data and the full-field iso-difference line data;

[0054] Step 5, repeat steps 1 to 4 to obtain the full-field stress under different loads and the evolution process with stress change;

[0055] Step 6, using the infrared testing system and infrared thermal imaging testing method to obtain in real time the temperature change of the opposite side of the test piece with the photoelastic patch material attached thereto due to the force, and then obtain the full-field stress distribution and evolution process;

[0056] There is no particular order for steps 5 and 6.

[0057] Among them, the experiments were carried out in a constant temperature and humidity environment.

[0058] In a preferred embodiment of the present invention, before step 1, the temperature of the surface of the test piece can be observed by an infrared thermal imager, and the experiment can be started when the temperature of the surface of the test piece is uniform.

[0059] Whenever a load is applied to the specimen in step 1, the optical axis positions of the polarizer and analyzer and the fast axis positions of the first quarter wave plate and the second quarter wave plate are rotated five times in steps 2 and 3, and the corresponding high-speed CMOS camera collects optical interference fringes five times. In step 6, the infrared thermal imaging of the infrared test system is collected once.

[0060] Specifically, the optical axis positions of the polarizer and the analyzer and the fast axis positions of the first quarter wave plate and the second quarter wave plate are rotated five times, and can be rotated according to the angles in the following table:

[0061] α π 6 c π / 2 π / 2 0 0 5π / 8 5π / 8 π / 8 π / 8 3π / 4 3π / 4 π / 4 π / 4 7π / 8 7π / 8 3π / 8 3π / 8 π / 2 3π / 4 π / 4 0

[0062] Wherein, α represents the angle of rotation of the optical axis of the polarizer from the x-axis, θ represents the angle of rotation of the fast axis of the first quarter wave plate from the x-axis, β represents the angle of rotation of the optical axis of the analyzer from the x-axis, and γ represents the angle of rotation of the fast axis of the second quarter wave plate from the x-axis.

[0063] By combining the five angles provided in the table, the full-field isotropy and isoclinic data can be directly obtained through a simple plane polarization instrument optical system, which can quickly and conveniently provide quantitative full-field stress results.

[0064] Although preferred embodiments of the present invention have been described, additional changes and modifications may be made to these embodiments by those skilled in the art once the basic inventive concepts are known. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention. Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A full-field stress synchronous test experimental system based on photoelasticity and infrared, characterized in that: include: Intelligent photoelastic testing system, infrared testing system, specimen loading system and synchronous control system; The specimen loading system is used to apply a load to the specimen, the specimen is a non-transparent rock-like solid material, and a photoelastic patch material with similar mechanical properties is attached to the surface; The intelligent photoelastic testing system is used to obtain the optical interference fringes generated by the force on the surface of the test piece with the photoelastic patch material in real time by using the photoelastic testing method, and then obtain the full-field stress distribution and the fringes evolution process with the stress change; The infrared testing system is used to obtain the temperature change of the opposite side of the test piece with the photoelastic patch material attached due to the force in real time by using the infrared thermal imaging testing method, and then obtain the full-field stress distribution and evolution process; The synchronous control system is used to control the optical axis position of the polarizer and the analyzer in the intelligent photoelastic testing system and the change frequency of the fast axis position of the first quarter wave plate and the second quarter wave plate, the frequency of the high-speed CMOS camera collecting optical interference fringes, the frequency of the specimen loading system applying load to the specimen, and the infrared thermal imaging collection frequency of the infrared testing system.

2. The photoelastic-infrared based full-field stress synchronous test experimental system according to claim 1, characterized in that: The synchronous control system is controlled by the following method: whenever the specimen loading system applies a load to the specimen, the optical axis positions of the polarizer and the analyzer and the fast axis positions of the first quarter wave plate and the second quarter wave plate in the intelligent photoelastic testing system rotate five times, the corresponding high-speed CMOS camera collects optical interference fringes five times, and the infrared thermal imaging of the infrared testing system collects once.

3. The photoelastic-infrared based full-field stress synchronous test experimental system according to claim 2, characterized in that: The optical axis positions of the polarizer and the analyzer and the fast axis positions of the first quarter wave plate and the second quarter wave plate in the intelligent photoelastic testing system are rotated five times including: rotating according to the angles in the following table; Wherein, α represents the angle of rotation of the optical axis of the polarizer from the x-axis, θ represents the angle of rotation of the fast axis of the first quarter wave plate from the x-axis, β represents the angle of rotation of the optical axis of the analyzer from the x-axis, and γ represents the angle of rotation of the fast axis of the second quarter wave plate from the x-axis.

4. The photoelastic-infrared based full-field stress synchronous testing experimental system according to claim 1, characterized in that: The specimen loading system includes a loading device and a loading control system. The loading device is provided with a fixture, and a specimen of non-transparent rock-like solid material with a photoelastic patch material attached to the surface is installed on the fixture. The loading control system is used to control the loading device to apply a load to the specimen through the fixture; the synchronous control system controls the frequency at which the loading control system applies a load to the specimen.

5. The photoelastic-infrared based full-field stress synchronous test experimental system according to claim 1, characterized in that: The intelligent photoelastic test system includes a photoelastic test optical path, a high-speed CMOS camera, a photoelastic image analysis system, a first controller, a second controller and a third controller; a white light source, a filter, a polarizer, a first quarter-wave plate, a beam expander, a convex lens, a second quarter-wave plate, an analyzer and a collimator are sequentially arranged along the photoelastic test optical path; the high-speed CMOS camera is used to receive the optical signal of the collimator and output a photoelastic interference image according to the optical signal and send it to the photoelastic image analysis system; the photoelastic image analysis system is used to calculate and analyze the full-field stress distribution of the specimen and the fringe evolution process with stress change using the photoelastic interference image; the first controller is used to control the optical axis position of the polarizer and the analyzer; The second controller is used to control the fast axis position of the first quarter wave plate and the second quarter wave plate; the third controller is used to control the start and end of the filter; the test piece is located between the beam expander and the convex lens, so that the light beam output by the beam expander covers the test piece and is reflected to the convex lens.

6. A full-field stress synchronous test experimental method based on photoelasticity and infrared, characterized in that: Using the photoelastic-infrared full-field stress synchronous testing experimental system according to any one of claims 1 to 5, the method comprises: Step 1, the specimen loading system applies a load to the specimen; Step 2, turn on the white light source, the white light is incident on the filter, the unfiltered white light is incident on the polarizer and converted into plane polarized light and then enters the first quarter wave plate, the generated circularly polarized light is incident on the beam expander, the light beam output by the beam expander covers the test piece and is reflected from the test piece to the convex lens, passes through the convex lens, passes through the second quarter wave plate and the analyzer, and enters the collimator, and finally the high-speed CMOS camera receives the light signal from the collimator and outputs the photoelastic interference image according to the light signal and sends it to the photoelastic image analysis system; at the same time, the optical axis positions of the polarizer and the analyzer are controlled by the first controller, and the fast axis positions of the first quarter wave plate and the second quarter wave plate are controlled by the second controller; the full-field equal inclination angle data are obtained; Step 3, start the third controller to filter the white light incident into the filter into monochromatic light, so that the monochromatic light is incident into the polarizer, and the subsequent method is the same as step 2; obtain full-field equidistant line data; Step 4, calculating the full-field stress according to the full-field isopiped data and the full-field iso-difference line data; Step 5, repeat steps 1 to 4 to obtain the full-field stress under different loads and the evolution process with stress change; Step 6, using the infrared testing system and infrared thermal imaging testing method to obtain in real time the temperature change of the opposite side of the test piece with the photoelastic patch material attached thereto due to the force, and then obtain the full-field stress distribution and evolution process; There is no particular order for steps 5 and 6.

7. The photoelastic-infrared full-field stress synchronous test experimental method according to claim 6, characterized in that: The experiments were carried out in a constant temperature and humidity environment.

8. The photoelastic-infrared full-field stress synchronous test experimental method according to claim 6, characterized in that: Before step 1, observe the temperature of the specimen surface with an infrared thermal imager, and start the experiment when the temperature of the specimen surface is uniform.

9. The photoelastic-infrared full-field stress synchronous testing experimental method according to claim 6, characterized in that: The method of controlling the optical axis positions of the polarizer and the analyzer by the first controller and controlling the fast axis positions of the first quarter wave plate and the second quarter wave plate by the second controller includes: each time the specimen loading system applies a load to the specimen, the optical axis positions of the polarizer and the analyzer and the fast axis positions of the first quarter wave plate and the second quarter wave plate rotate five times, the corresponding high-speed CMOS camera collects optical interference fringes five times, and the infrared thermal imaging of the infrared testing system collects once.

10. The photoelastic-infrared based full-field stress synchronous testing experimental method according to claim 9, characterized in that: The optical axis positions of the polarizer and the analyzer and the fast axis positions of the first quarter wave plate and the second quarter wave plate are rotated five times including: rotating according to the angles in the following table; Wherein, α represents the angle of rotation of the optical axis of the polarizer from the x-axis, θ represents the angle of rotation of the fast axis of the first quarter wave plate from the x-axis, β represents the angle of rotation of the optical axis of the analyzer from the x-axis, and γ represents the angle of rotation of the fast axis of the second quarter wave plate from the x-axis.

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