A True Triaxial Loading Test Device and Method for Material Mechanical Properties

Abstract

This invention relates to a true triaxial loading testing device and method for the mechanical properties of materials, belonging to the field of precision scientific instruments. Two precision rotating modules are respectively fixed to the upper and lower surfaces inside a positioning support module via attitude adjustment platforms. The in-situ loading testing module is fixed to the precision rotating modules, and its clamps are used to fix the sample. The advantages of this invention are its novel structure; the in-situ loading testing module can perform uniaxial, biaxial, and triaxial static and dynamic tensile and compressive loading on the sample; it can be integrated with various imaging devices; and the relative positions of the two imaging devices in the imaging module can be precisely controlled. The precision rotating module can drive the in-situ loading testing module to rotate, ensuring that the imaging module can continuously and synchronously characterize the sample from 0 to 360°, revealing the damage and failure mechanisms of the material.

Description

Technical Field

[0001] This invention belongs to the field of precision scientific instruments, and in particular relates to a true triaxial loading test device and test method for the mechanical properties of materials. It can perform true triaxial static and dynamic mechanical loading on materials, and at the same time, it can use different imaging devices to characterize the changes in the internal structure of materials from multiple angles in real time, providing a reliable means to study the relationship between material damage and failure mechanisms and mechanical properties. Background Technology

[0002] As we all know, all materials are constantly subjected to various complex forces during use, such as tension, bending, fatigue, torsion, shearing, and so on. Under these complex mechanical loads, materials may experience various failure modes in practical applications, causing significant damage to life and property. Only by analyzing the relationship between the internal damage mechanism and mechanical properties of materials can we more rationally improve the composition and structure of workpieces, enhance performance, and avoid uncontrollable losses caused by accidental damage.

[0003] When traditional triaxial loading testing techniques are combined with imaging characterization techniques, continuous imaging of the specimen is often impossible due to spatial interference and obstruction. Alternatively, the limited flexibility of traditional mechanical testing machines means that the relative positions of different imaging devices are often fixed and cannot be adjusted when used together, resulting in imaging results obtained from a certain positional relationship. Both of these reasons make it impossible to clearly obtain the internal changes and structure of the material. Therefore, researching and revealing the relationship between the damage and failure mechanisms of materials and their mechanical properties, and establishing the structure-property relationship between complex multi-scale structures and mechanical behavior, has become a key scientific challenge to ensure the rationality and reliability of the use of various materials. Summary of the Invention

[0004] This invention provides a true triaxial loading testing device and method for material mechanical properties, addressing the limitations of traditional mechanical loading methods, poor compatibility of imaging equipment, inability to adjust the relative positions of different imaging devices, and difficulty in achieving continuous imaging under true triaxial loading. This invention uses a positioning support frame to fix the precision rotation module and the in-situ loading testing module, ensuring the complexity of the mechanical loading process and enabling simultaneous loading and rotation of the sample. The three loading axes of this device are not in the horizontal / vertical direction, enabling simultaneous 0-360° in-situ testing and characterization of the sample. The frame has two pre-reserved interfaces for imaging equipment on both sides, allowing for flexible integration of two sets of high-resolution imaging devices. The device uses a geared roller drive to achieve adjustable relative positions of the imaging devices, enabling multi-view imaging of the sample.

[0005] The technical solution adopted in this invention is: a true triaxial loading test device for material mechanical properties, comprising a positioning support module, a precision rotation module, and an in-situ loading test module, wherein two precision rotation modules are respectively fixed to the upper and lower surfaces inside the positioning support module via attitude adjustment tables, the in-situ loading test module is fixed on the precision rotation module, and the clamps of the in-situ loading test module are used to fix the sample.

[0006] The positioning support module of this invention includes a positioning frame, a receiver mounting bracket for imaging device one, a receiver mounting slide for imaging device two, a receiver mounting bracket for imaging device two, a light source mounting bracket for imaging device one, a displacement platform, a light source mounting bracket for imaging device two, a light source mounting slide for imaging device two, a geared ring mounting plate, a geared ring, a receiving part for imaging device one, a receiving part for imaging device two, a sliding plate, a light source part for imaging device two, a light source part for imaging device one, and a guide post. The geared ring mounting plate is mounted on the displacement platform, the geared ring is mounted on the geared ring mounting plate, the sliding plate is mounted on the support rod of the displacement platform, the guide post is fixed to the displacement platform, and the frame is positioned by the guide post and pressed against the sliding plate. The receiving part for imaging device one is mounted on the displacement platform, and the receiving part for imaging device one... The receiver mounting bracket is installed on the receiving part of the imaging device one, the light source part of the imaging device one is installed on the displacement platform, the light source mounting bracket of the imaging device one is installed on the light source part of the imaging device one, the receiving part of the imaging device two is installed on the displacement platform, the receiver mounting bracket of the imaging device two is installed on the receiving part of the imaging device two, the receiver mounting slide of the imaging device two is installed on the receiver mounting bracket of the imaging device two, the light source part of the imaging device two is installed on the displacement platform, the light source mounting bracket of the imaging device two is installed on the light source part of the imaging device two, and the light source mounting slide of the imaging device two is installed on the light source mounting bracket of the imaging device two. The receiving part of the imaging device one, the light source part of the imaging device one, the receiving part of the imaging device two, and the light source part of the imaging device two are respectively engaged with the gear ring through rollers.

[0007] The displacement platform of this invention includes a first-layer base plate, a second-layer base plate, a third-layer base plate, a support rod, a center hole, first and second-layer support plates, first and second-layer guide rails, first and second-layer sliders, a second and third-layer motor adapter plate, a second and third-layer motor, a second and third-layer support plate, a second and third-layer guide rail, a second and third-layer slider, a first and second-layer motor adapter plate, and feet. The second and third-layer support plates are mounted on the third-layer base plate, the second and third-layer guide rails are fixed to the second and third-layer support plates, and the second and third-layer sliders are mounted on the second and third-layer guide rails according to the guide rail slider mating method. The second and third-layer motor adapter plate is fixed to the third-layer base plate, and the second and third-layer motors are fixed to the second and third-layer support plates. The motor adapter plate is used to move the second-layer base plate. The first and second-layer support plates are installed on the second-layer base plate, and the first and second-layer guide rails are fixed on the first and second-layer support plates. The first and second-layer sliders are installed on the first and second-layer guide rails according to the matching method of the guide rail sliders. The first and second-layer motor adapter plates are fixed on the second-layer base plate, and the first and second-layer motors are fixed on the first and second-layer motor adapter plates. Their function is to move the first-layer base plate. The support electric rod is installed on the third-layer base plate. Its function is to support the frame and realize vertical displacement. The gear ring mounting plate is installed on the first-layer base plate and is concentric with the center hole. The sliding plate is installed on the support electric rod.

[0008] The receiving part of the imaging device of the present invention includes an imaging device receiver angle plate, an imaging device receiver guide rail, an imaging device receiver slider, an imaging device receiver roller, and an imaging device receiver motor. The imaging device receiver angle plate is mounted on a base plate and is concentric with the center hole. The imaging device receiver guide rail is mounted on the imaging device receiver angle plate. The imaging device receiver slider is mounted on the imaging device receiver guide rail. The imaging device receiver mounting bracket is mounted on the imaging device receiver slider. The imaging device receiver motor is mounted at the front end of the imaging device receiver mounting bracket, and its pin is inserted into the pin hole of the imaging device receiver roller, ensuring that the roller meshes with the gear ring.

[0009] The imaging device light source section of the present invention includes an imaging device light source angle plate, an imaging device light source guide rail, an imaging device light source slider, an imaging device light source roller, and an imaging device light source motor. The imaging device light source angle plate is mounted on a base plate and is concentric with the center. The imaging device light source guide rail is mounted on the imaging device light source angle plate. The imaging device light source slider is mounted on the imaging device light source guide rail. The imaging device light source mounting bracket is mounted on the imaging device light source slider. The imaging device light source motor is mounted at the front end of the imaging device light source mounting bracket, and its pin is inserted into the pin hole of the imaging device light source roller, ensuring that the roller meshes with the gear ring.

[0010] The receiving part of the imaging device 2 of the present invention includes an imaging device 2 receiver angle plate, an imaging device 2 receiver guide rail, an imaging device 2 receiver slider, an imaging device 2 receiver roller, and an imaging device 2 receiver motor. The imaging device 2 receiver angle plate is mounted on a base plate and is concentric with the center hole. The imaging device 2 receiver guide rail is mounted on the imaging device 2 receiver angle plate. The imaging device 2 receiver slider is mounted on the imaging device 2 receiver guide rail. The imaging device 2 receiver mounting bracket is mounted on the imaging device 2 receiver slider. The imaging device 2 receiver motor is mounted at the front end of the imaging device 2 receiver mounting bracket, and its pin is inserted into the pin hole of the imaging device 2 receiver roller, ensuring that the imaging device 2 receiver roller meshes with the gear ring. The imaging device 2 receiver mounting slide is mounted on the imaging device 2 receiver mounting bracket.

[0011] The imaging device secondary light source section of the present invention includes an imaging device secondary light source angle plate, an imaging device secondary light source guide rail, an imaging device secondary light source slider, an imaging device secondary light source roller, and an imaging device secondary light source motor. The imaging device secondary light source angle plate is mounted on a base plate and is concentric with the center hole. The imaging device secondary light source guide rail is mounted on the imaging device secondary light source angle plate. The imaging device secondary light source slider is mounted on the imaging device secondary light source guide rail. The imaging device secondary light source mounting bracket is mounted on the imaging device secondary light source slider. The imaging device secondary light source motor is mounted at the front end of the imaging device secondary light source mounting bracket, and its pin is inserted into the pin hole of the imaging device secondary light source roller, ensuring that the imaging device secondary light source roller meshes with the gear ring. The imaging device secondary light source mounting slide is mounted on the imaging device secondary light source mounting bracket.

[0012] The precision rotation module of this invention includes a precision turntable, a turntable attitude adjustment platform, and an auxiliary support. The turntable attitude adjustment platform is installed on the upper and lower parts inside the positioning frame of the positioning support module. The precision turntable is installed on the turntable attitude adjustment platform and is coaxial with the center hole reserved in the bottom plate of the displacement platform. By adjusting the turntable attitude adjustment platform, it is coaxial with the precision turntable on the other side. The auxiliary support is installed after the coaxiality is adjusted and is connected to the precision turntable by adding or removing shims.

[0013] The turntable attitude adjustment platform of the present invention includes a turntable pitch adjustment platform, a turntable x displacement adjustment platform and a turntable y displacement adjustment platform, wherein the turntable pitch adjustment platform is fixedly connected above the turntable y displacement adjustment platform, and the turntable x displacement adjustment platform is installed below the turntable y displacement adjustment platform.

[0014] The in-situ loading test module of this invention includes a fixed plate, an adapter plate, an attitude adjustment stage, a linear slide base plate, a short guide rail slider, a magnetic circuit, a mover, a slide, a fixture, a center hole in the fixed plate, a reserved interface in the fixed plate, a pitch adjustment platform for the turntable, an x-displacement adjustment platform, a y-displacement adjustment platform, a short guide rail, a short slider, a centering plate, a centering plate cover, a fixed fixture, a mounting fixture, and auxiliary fixtures. The fixed plate is mounted on a precision turntable and has a center hole. The y-displacement adjustment platform of the attitude adjustment stage is mounted on the fixed plate via the adapter plate. On the interface reserved on the fixed plate, the linear slide base plate is installed on the pitch adjustment platform of the attitude adjustment table. The x-displacement adjustment platform is located between the pitch adjustment platform and the y-displacement adjustment platform. The magnetic circuit and the short guide rail slider are both installed on the linear slide base plate. The short slider is slidably connected to the short guide rail. The mover is attracted to the magnetic circuit. The upper end of the slide and the mover and the guide rail slider are fixed at the same time. The centering plate is installed on the slide. The centering plate cover is fastened to the centering plate by screws. The fixing fixture is stuck between the two. The mounting fixture is fastened to the fixing fixture by screws.

[0015] The front end of the fixing fixture of the present invention is designed with threads, and the auxiliary fixture is fixed to the front end of the fixing fixture through a threaded connection.

[0016] A test method using a true triaxial loading test device for material mechanical properties includes the following steps:

[0017] Step 1, Sample clamping: Remove the six mounting clamps from the three loading shafts, fasten the sample to the fixing clamp, fasten the mounting clamps back on and tighten them with screws, and then close the complex working condition simulation module.

[0018] Step 3: Turn on the imaging module: Turn on the light source and receiver of both imaging devices;

[0019] Step 4: Static and Dynamic Tensile and Compression Loading: The linear motor actuator is energized to subject the material to static tensile and compression loading or fatigue testing. The stress on any plane of the specimen is analyzed using the following formula:

[0020]

[0021]

[0022] σ1: The maximum applied stress 1, and the component of this stress in the selected plane is taken as the normal of the selected plane;

[0023] σ2: Applied intermediate stress 2;

[0024] σ3: Minimum applied stress of 3;

[0025] σ: The normal stress on any plane of any infinitesimal element in the specimen;

[0026] τ: Shear stress on any plane of any infinitesimal element in the specimen;

[0027] α: The acute angle between stress σ1 and the selected plane;

[0028] β: The acute angle between stress σ2 and the selected plane;

[0029] θ: The acute angle between stress σ3 and the selected plane;

[0030] The acute angle between the corresponding component forces of stresses σ1 and σ2 projected onto the selected plane;

[0031] The acute angle between the corresponding component forces of stresses σ1 and σ3 projected onto the selected plane;

[0032] Step 5, Continuous Imaging and Stereoscopic Characterization: Start the precision rotary stage. The rotation of the precision rotary stage drives the static and dynamic loading module to rotate, so that the imaging module can continuously image the sample from 0 to 360°. At the same time, the motors of the imaging device-light source and the imaging device-receiver can be started to adjust the relative positions of the two imaging devices and obtain comparative images from different perspectives. However, during the adjustment, it is necessary to ensure that the corresponding light source and receiver are on the same straight line.

[0033] Step 6: Shut down the equipment: Keep the experimental data and ensure that all modules are turned off. By comparing the stress analysis results of any plane of the tested material obtained in Step 4 with the image of the tested material obtained in Step 5, the mechanical behavior of the tested material under true triaxial loading can be obtained.

[0034] This invention addresses the relationship between internal damage and failure mechanisms and mechanical properties of materials. It presents a true triaxial loading testing device and method for material mechanical properties, overcoming the limitations of traditional uniaxial / biaxial tensile / compression, bending, and torsional loading. Furthermore, it utilizes different imaging devices to characterize the internal structure of materials at different scales. This true triaxial loading testing device and method enables static and dynamic loading of materials under true triaxial mechanical loads. Simultaneously, the relative positions of two imaging devices can be precisely controlled, allowing for continuous imaging of the sample from 0 to 360°, yielding a three-dimensional characterization of the material's internal structure. This is of great significance for studying the failure mechanisms of materials under mechanical loads and for improving their performance.

[0035] The beneficial effects of this invention are as follows:

[0036] 1. This invention comprises four main parts: a positioning support module, an imaging module, a precision rotation module, and an in-situ loading test module. The invention is highly modular and standardized, facilitating debugging, installation, and subsequent maintenance.

[0037] 2. This invention fully leverages the complementarity of different imaging devices. The relative positions of the two imaging devices can be changed during the imaging process, thereby obtaining comparative images of the internal structure of the sample from multiple perspectives, revealing its damage and failure mechanism, and constructing a structure-property relationship between multi-scale structural evolution and mechanical behavior, providing a guarantee for the research and development and application of materials with more complex compositions and more special structures.

[0038] 3. This invention creatively applies optical principles to the field of testing machines. With the assistance of a collimator and a roof prism, it completes the installation of a triaxial orthogonal static and dynamic loading assembly. This ensures that none of the three loading axes are in the horizontal / vertical direction, enabling true triaxial static and dynamic loading of the material while ensuring that the imaging equipment can perform synchronous and in-situ testing and characterization of the sample from 0 to 360°. This yields the three-dimensional structural characterization results of the material, providing strong support for studying the actual storage / service state of the material. Furthermore, the auxiliary fixture design also provides good compatibility with non-metallic samples. Attached Figure Description

[0039] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a schematic diagram of the structure of the present invention;

[0041] Figure 2 This is a schematic diagram illustrating the loading test principle of the present invention;

[0042] Figure 3 This is a structural schematic diagram of the positioning support module of the present invention;

[0043] Figure 4 This is a schematic diagram of the displacement platform in the positioning support module of the present invention;

[0044] Figure 5 This is a top view of the toothed ring mounting plate, toothed ring, receiving part of imaging device one, receiving part of imaging device two, sliding plate, light source part of imaging device two, and light source part of imaging device one in the positioning support module of the present invention.

[0045] Figure 6 This is a schematic diagram of the receiving part of the imaging device in the positioning support module of the present invention;

[0046] Figure 7 This is a schematic diagram of the light source part of the imaging device in the positioning support module of the present invention;

[0047] Figure 8This is a schematic diagram of the receiving part of the imaging device 2 in the positioning support module of the present invention;

[0048] Figure 9 This is a schematic diagram of the structure of the two light sources of the imaging device in the positioning support module of the present invention;

[0049] Figure 10 This is a schematic diagram of the structure of the precision rotation module of the present invention;

[0050] Figure 11 This is a schematic diagram of the turntable attitude adjustment platform in the precision rotation module of the present invention;

[0051] Figure 12 This is a schematic diagram of the in-situ loading test module of the present invention;

[0052] Figure 13 This is a schematic diagram of the structure of the linear slide base plate, short guide rail slider, magnetic circuit, and mover in the in-situ loading test module of this invention;

[0053] Figure 14 This is a schematic diagram of the structure of the fixed plate, adapter plate, and attitude adjustment platform in the in-situ loading test module of this invention;

[0054] Figure 15 This is a schematic diagram of the fixture in the in-situ loading test module of the present invention;

[0055] Figure 16 This is a schematic diagram of the structure of the test sample of this invention;

[0056] In the diagram, 1. Positioning support module, 2. Precision rotation module, 3. In-situ loading test module, 101. Positioning frame, 102. Imaging device one receiver mounting bracket, 103. Imaging device two receiver mounting slide, 104. Imaging device two receiver mounting bracket, 105. Imaging device one light source mounting bracket, 106. Displacement platform, 107. Imaging device two light source mounting bracket, 108. Imaging device two light source mounting slide, 109. Gear ring mounting plate, 110. Gear ring, 111. Imaging device one receiving part, 112. Imaging device two receiving part, 113. Sliding plate, 114. Imaging device two light source part, 115. Imaging device one light source part, 116. Guide column, 10601. First layer base plate, 10602. 10603 Second-layer base plate, 10604 Third-layer base plate, 10605 Support rod, 10606 Center hole, 10607 First and second-layer support plates, 10608 First and second-layer guide rails, 10609 First and second-layer sliders, 10610 Second and third-layer motor adapter plate, 10611 Second and third-layer motors, 10612 Second and third-layer guide rails, 10613 Second and third-layer sliders, 10614 First and second-layer motors, 10615 First and second-layer motor adapter plate, 10616 Foot, 11401 Imaging equipment second light source angle plate, 11402 Imaging equipment second light source guide rail, 11403 Imaging equipment second light source slider, 11404 Imaging equipment second light source roller, 11405 Imaging equipment Two light source motors, 11201; two receiver angle plates for imaging equipment, 11202; two receiver guide rails for imaging equipment, 11203; two receiver sliders for imaging equipment, 11204; two receiver rollers for imaging equipment, 11205; two receiver motors for imaging equipment, 11101; one receiver angle plate for imaging equipment, 11102; one receiver guide rail for imaging equipment, 11103; one receiver slider for imaging equipment, 11104; one receiver roller for imaging equipment, 11105; one receiver motor for imaging equipment, 11501; one light source angle plate for imaging equipment, 11502; one light source guide rail for imaging equipment, 11503; one light source slider for imaging equipment, 11504; one light source roller for imaging equipment, 11505; ... The components include: a light source motor, a precision turntable, a turntable attitude adjustment platform, an auxiliary support, a turntable pitch adjustment platform, a turntable x-displacement adjustment platform, a turntable y-displacement adjustment platform, a fixed plate, an adapter plate, an attitude adjustment platform, a linear slide base plate, a short guide rail slider, a magnetic circuit, a mover, a slide, a fixture, a short guide rail, a short slider, a fixed plate center hole, a fixed plate reserved interface, a turntable pitch adjustment platform, an x-displacement adjustment platform, and a y-displacement adjustment platform.30901. Centering plate; 30902. Centering plate cover; 30903. Fixing clamp; 30904. Mounting clamp; 30905. Auxiliary clamp; 30906. Sample. Detailed Implementation

[0057] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0058] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can also be implemented in sequences other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0059] like Figure 1 As shown, a true triaxial loading test device for the mechanical properties of materials includes a positioning support module 1, a precision rotation module 2, and an in-situ loading test module 3. The two precision rotation modules 2 are respectively fixed to the upper and lower surfaces inside the positioning support module 1 via an attitude adjustment table 202. The in-situ loading test module 3 is fixed on the precision rotation module 2, and the clamps of the in-situ loading test module 3 are used to fix the sample.

[0060] like Figure 3 , 5As shown, the positioning support module 1 includes a positioning frame 101, an imaging device one receiver mounting bracket 102, an imaging device two receiver mounting slide 103, an imaging device two receiver mounting bracket 104, an imaging device one light source mounting bracket 105, a displacement platform 106, an imaging device two light source mounting bracket 107, an imaging device two light source mounting slide 108, a gear ring mounting plate 109, a gear ring 110, an imaging device one receiving part 111, an imaging device two receiving part 112, a sliding plate 113, an imaging device two light source part 114, and an imaging device one... The light source section 115 and guide post 116 are configured such that a gear ring mounting plate 109 is mounted on the displacement platform 106, a gear ring 110 is mounted on the gear ring mounting plate 109, a sliding plate 113 is mounted on the support rod 10604 of the displacement platform 106, the guide post 116 is fixed to the displacement platform 106, and the frame 101 is positioned by the guide post 116 and pressed against the sliding plate 113; an imaging device receiving section 111 is mounted on the displacement platform 106, and an imaging device receiver mounting bracket 102 is mounted on the imaging device receiving section 111; the imaging device... A light source section 115 is mounted on a displacement platform 106. A light source mounting bracket 105 for imaging equipment 1 is mounted on the light source section 115 of imaging equipment 1. A receiving section 112 for imaging equipment 2 is mounted on the displacement platform 106. A receiver mounting bracket 104 for imaging equipment 2 is mounted on the receiving section 112 of imaging equipment 2. A receiver mounting slide 103 for imaging equipment 2 is mounted on the receiver mounting bracket 104 of imaging equipment 2. A light source section 114 for imaging equipment 2 is mounted on the displacement platform 106. A light source mounting bracket 107 for imaging equipment 2 is mounted on the light source section of imaging equipment 2. On part 114, the mounting slide 108 for the second imaging device light source is mounted on the mounting bracket 107 for the second imaging device light source. The receiving part 111, the light source part 115, the receiving part 112, and the light source part 114 of the first imaging device are respectively engaged with the gear ring 110 through rollers. The rollers are driven by a motor to rotate around the gear ring 110, ensuring that the receiver and light source of the first imaging device are in a straight line and the receiver and light source of the second imaging device are in a straight line. At the same time, the angle between the two imaging devices can be adjusted.

[0061] like Figure 4As shown, the displacement platform 106 includes a first base plate 10601, a second base plate 10602, a third base plate 10603, a support rod 10604, a center hole 10605, first and second layer support plates 10606, first and second layer guide rails 10607, first and second layer sliders 10608, second and third layer motor adapter plates 10609, second and third layer motors 10610, second and third layer support plates 10611, second and third layer guide rails 10612, and second and third layer sliders 10608. 613, first and second layer motors 10614, first and second layer motor adapter plate 10615, base 10616, wherein the second and third layer support plate 10611 is installed on the third layer base plate 10603, the second and third layer guide rails 10612 are fixed on the second and third layer support plate 10611, and the second and third layer sliders 10613 are installed on the second and third layer guide rails 10612 according to the guide rail slider matching method; the second and third layer motor adapter plate 10609 is fixed on the third layer base plate 10603, the second and third layers... The first-layer motor 10610 is fixed on the second- and third-layer motor adapter plate 10609, and its function is to drive the second-layer base plate 10602 to move. The first- and second-layer support plates 10606 are installed on the second-layer base plate 10602, the first- and second-layer guide rails 10607 are fixed on the first- and second-layer support plates 10606, and the first- and second-layer sliders 10608 are installed on the first- and second-layer guide rails 10607 according to the guide rail slider cooperation method. The first- and second-layer motor adapter plate 10615 is fixed on the second-layer base plate 10602. On 602, the first and second layer motors 10614 are fixed on the first and second layer motor adapter plate 10615, and their function is to drive the first layer base plate 10601 to move; the support rod 10604 is installed on the third layer base plate 10603, and its function is to support the frame 101 and realize vertical displacement; the gear ring mounting plate 109 is installed on the first layer base plate 10601 and is concentric with the center hole 10605; the sliding plate 113 is installed on the support rod 10604.

[0062] like Figure 6As shown, the receiving part 111 of the imaging device includes an imaging device receiver angle plate 11101, an imaging device receiver guide rail 11102, an imaging device receiver slider 11103, an imaging device receiver roller 11104, and an imaging device receiver motor 11105. The imaging device receiver angle plate 11101 is mounted on a base plate 10601 and is concentric with the center hole 10605. The imaging device receiver guide rail 11102 is mounted on the imaging device receiver angle plate 11103. On the 1st, the image device receiver slider 11103 is mounted on the image device receiver guide rail 11102, the image device receiver mounting bracket 102 is mounted on the image device receiver slider 11103, the image device receiver motor 11105 is mounted on the front end of the image device receiver mounting bracket 102, and its pin is inserted into the pin hole of the image device receiver roller 11104, ensuring that the roller 11104 meshes with the gear ring 110. The image device receiver can then be mounted on the image device receiver mounting bracket 102.

[0063] like Figure 7 As shown, the imaging device light source section 115 includes an imaging device light source angle plate 11501, an imaging device light source guide rail 11502, an imaging device light source slider 11503, an imaging device light source roller 11504, and an imaging device light source motor 11505. The imaging device light source angle plate 11501 is mounted on a base plate 10601 and is concentric with the center 10605. The imaging device light source guide rail 11502 is mounted on the imaging device light source angle plate 11503. 1. The imaging device light source slider 11503 is mounted on the imaging device light source guide rail 11502. The imaging device light source mounting bracket 105 is mounted on the imaging device light source slider 11503. The imaging device light source motor 11505 is mounted on the front end of the imaging device light source mounting bracket 105. Its pin is inserted into the pin hole of the imaging device light source roller 11504, ensuring that the roller 11504 meshes with the gear ring 110. The imaging device light source can then be mounted on the imaging device light source mounting bracket 105.

[0064] like Figure 8As shown, the receiving part 112 of the imaging device 2 includes an imaging device 2 receiver angle plate 11201, an imaging device 2 receiver guide rail 11202, an imaging device 2 receiver slider 11203, an imaging device 2 receiver roller 11204, and an imaging device 2 receiver motor 11205. The imaging device 2 receiver angle plate 11201 is mounted on a base plate 10601 and is concentric with the center hole 10605. The imaging device 2 receiver guide rail 11202 is mounted on the imaging device 2 receiver angle plate 11201, and the imaging device 2 receiver slider 11203 is mounted on the base plate 10601. The image device two receiver guide rail 11202 is mounted on the image device two receiver mounting bracket 104, which is mounted on the image device two receiver slider 11203. The image device two receiver motor 11205 is mounted on the front end of the image device two receiver mounting bracket 104, with its pin inserted into the pin hole of the image device two receiver roller 11204, ensuring that the image device two receiver roller 11204 meshes with the gear ring 110. The image device two receiver mounting slide 103 is mounted on the image device two receiver mounting bracket 104. The image device two receiver can then be mounted on the image device two receiver mounting slide 103.

[0065] like Figure 9 As shown, the imaging device's second light source section 114 includes an imaging device second light source angle plate 11401, an imaging device second light source guide rail 11402, an imaging device second light source slider 11403, an imaging device second light source roller 11404, and an imaging device second light source motor 11405. The imaging device second light source angle plate 11401 is mounted on a base plate 10601 and is concentric with the center hole 10605. The imaging device second light source guide rail 11402 is mounted on the imaging device second light source angle plate 11401, and the imaging device second light source slider 11403 is mounted on... On the guide rail 11402 of the imaging device's second light source, the mounting bracket 107 of the imaging device's second light source is mounted on the slider 11403 of the imaging device's second light source. The motor 11405 of the imaging device's second light source is mounted on the front end of the mounting bracket 107 of the imaging device's second light source, and its pin is inserted into the pin hole of the roller 11404 of the imaging device's second light source, ensuring that the roller 11404 of the imaging device's second light source meshes with the gear ring 110. The mounting slide 108 of the imaging device's second light source is mounted on the mounting bracket 107 of the imaging device's second light source. The imaging device's second light source can then be mounted on the mounting slide 108 of the imaging device's second light source.

[0066] like Figure 10As shown, the precision rotation module 2 includes a precision turntable 201, a turntable attitude adjustment platform 202, and an auxiliary support 203. The turntable attitude adjustment platform 202 is installed on the upper and lower parts of the positioning frame 101 inside the positioning support module 1. The precision turntable 201 is installed on the turntable attitude adjustment platform 202 and is coaxial with the center hole 10605 reserved in the bottom plate 10601 of the displacement platform 106. The center axis is found using a collimator and a lens group. By adjusting the turntable attitude adjustment platform 202, it is made coaxial with the precision turntable 201 on the other side. The auxiliary support 203 is installed after the coaxiality is adjusted. It is connected to the precision turntable 201 by adding or removing shims to prevent the turntable attitude adjustment platform 202 from being crushed.

[0067] like Figure 11 As shown, the turntable attitude adjustment platform 202 includes a turntable pitch adjustment platform 20201, a turntable x displacement adjustment platform 20202, and a turntable y displacement adjustment platform 20203. The turntable pitch adjustment platform 20201 is fixedly connected above the turntable y displacement adjustment platform 20203, and the turntable y displacement adjustment platform 20203 is installed on the turntable x displacement adjustment platform 20202 below the turntable x displacement adjustment platform 20202.

[0068] like Figure 12 , 13As shown in Figures 14 and 15, the in-situ loading test module 3 includes a fixed plate 301, an adapter plate 302, an attitude adjustment stage 303, a linear slide base plate 304, a short guide rail slider 305, a magnetic circuit 306, a mover 307, a slide 308, a fixture 309, a fixed plate center hole 30101, a fixed plate reserved interface 30102, a turntable pitch adjustment platform 30301, an x-displacement adjustment platform 30302, a y-displacement adjustment platform 30303, a short guide rail 30501, a short slider 30502, a centering plate 30901, a centering plate cover 30902, a fixed fixture 30903, a mounting fixture 30904, and an auxiliary fixture 30905. The fixed plate 301 is mounted on the precision turntable 201 and has a fixed plate center hole 30101. The y-displacement adjustment platform 30303 of the attitude adjustment stage 303 is connected via a rotating... The connecting plate 302 is installed on the interface 30102 reserved on the fixed plate 301. The linear slide base plate 304 is installed on the turntable pitch adjustment platform 30301 of the attitude adjustment table 303. The x-displacement adjustment platform 30302 is located between the turntable pitch adjustment platform 30301 and the y-displacement adjustment platform 30303. The magnetic circuit 306 and the short guide rail slider 305 are both installed on the linear slide base plate 304. The short slider 30502 is slidably connected to the short guide rail 30501. The mover 307 is attracted to the magnetic circuit 306. The slide 308, the upper end of the mover 307, and the guide rail slider 305 are fixed at the same time. The centering plate 30901 is installed on the slide 308. The centering plate cover 30902 is fastened to the centering plate 30901 by screws. The fixing clamp 30903 is stuck between the two. The mounting clamp 30904 is fastened to the fixing clamp 30903 by screws.

[0069] The front end of the fixed clamp 30903 is designed with threads, and the auxiliary clamp 30905 is fixed to the front end of the fixed clamp 30903 by threaded connection.

[0070] When conducting a true triaxial loading test on the mechanical properties of a material, this invention can be referred to... Figure 2 , 16 The diagram shown illustrates the loading test principle. This example uses the most complex three-axis loading method, and the specific steps are as follows:

[0071] Step 1, clamping the sample: Remove the six mounting clamps 30904 from the three loading shafts, fasten the sample to the fixing clamp 30903, then fasten the mounting clamp 30904 and tighten it with screws, and then close the complex working condition simulation module 4.

[0072] Step 3: Turn on the imaging module: Turn on the light source and receiver of both imaging devices;

[0073] Step 4: Static and Dynamic Tensile and Compression Loading: The linear motor mover 307 is energized to subject the material to static tensile and compression tests or fatigue tests. The stress on any plane of the specimen is analyzed using the following formula:

[0074]

[0075]

[0076] σ1: The maximum applied stress 1, and the component of this stress in the selected plane is taken as the normal of the selected plane;

[0077] σ2: Applied intermediate stress 2;

[0078] σ3: Minimum applied stress of 3;

[0079] σ: The normal stress on any plane of any infinitesimal element in the specimen;

[0080] τ: Shear stress on any plane of any infinitesimal element in the specimen;

[0081] α: The acute angle between stress σ1 and the selected plane;

[0082] β: The acute angle between stress σ2 and the selected plane;

[0083] θ: The acute angle between stress σ3 and the selected plane;

[0084] The acute angle between the corresponding component forces of stresses σ1 and σ2 projected onto the selected plane;

[0085] The acute angle between the corresponding component forces of stresses σ1 and σ3 projected onto the selected plane;

[0086] Step 5, Continuous Imaging and Stereoscopic Characterization: Start the precision rotary stage 201. The rotation of the precision rotary stage 201 drives the static and dynamic loading module 3 to rotate, so that the imaging module can continuously image the sample from 0 to 360°. At the same time, the imaging device-light source motor 11405 and the imaging device-receiver motor 11205 can be started. Adjust the relative positions of the two imaging devices to obtain comparative images from different perspectives. However, during the adjustment, it is necessary to ensure that the corresponding light source and receiver are on the same straight line.

[0087] Step 6: Shut down the equipment: Keep the experimental data and ensure that all modules are turned off. By comparing the stress analysis results of any plane of the tested material obtained in Step 4 with the image of the tested material obtained in Step 5, the mechanical behavior of the tested material under true triaxial loading can be obtained.

Claims

1. A true triaxial loading testing device for the mechanical properties of materials, characterized in that: It includes a positioning support module, a precision rotation module, and an in-situ loading test module. The two precision rotation modules are respectively fixed to the upper and lower surfaces inside the positioning support module via a turntable attitude adjustment platform. The in-situ loading test module is fixed on the precision rotation module, and the fixture of the in-situ loading test module is used to fix the sample. The positioning support module includes a positioning frame and a displacement platform. The displacement platform has a multi-layer base plate and a support rod to achieve horizontal and vertical position adjustment. The precision rotation module includes a precision turntable and a turntable attitude adjustment platform. The turntable attitude adjustment platform includes a pitch adjustment platform, an x-displacement adjustment platform, and a y-displacement adjustment platform. The precision turntable is mounted on the turntable attitude adjustment platform, and the precision turntables of the two precision rotation modules are coaxially arranged. The in-situ loading test module includes a fixed plate, an adapter plate, an attitude adjustment stage, a linear slide base plate, a short guide rail slider, a magnetic circuit, a mover, a slide, a fixture, a center hole in the fixed plate, a reserved interface in the fixed plate, a pitch adjustment platform for the turntable, an x-displacement adjustment platform, a y-displacement adjustment platform, a short guide rail, a short slider, a centering plate, a centering plate cover, a fixed fixture, a mounting fixture, and auxiliary fixtures. The fixed plate is mounted on the precision turntable and has a center hole. The y-displacement adjustment platform of the attitude adjustment stage is mounted on the fixed plate via the adapter plate. On the pre-reserved interface of the plate, the linear slide base plate is installed on the pitch adjustment platform of the attitude adjustment table. The x-displacement adjustment platform is located between the pitch adjustment platform and the y-displacement adjustment platform. The magnetic circuit and the short guide rail slider are both installed on the linear slide base plate. The short slider is slidably connected to the short guide rail. The mover is attracted to the magnetic circuit. The upper end of the slide and the mover and the guide rail slider are fixed at the same time. The centering plate is installed on the slide. The centering plate cover is fastened to the centering plate by screws. The fixing fixture is stuck between the two. The mounting fixture is fastened to the fixing fixture by screws.

2. The true triaxial loading testing device for material mechanical properties according to claim 1, characterized in that: The positioning support module further includes a receiver mounting bracket for imaging device one, a receiver mounting slide for imaging device two, a receiver mounting bracket for imaging device two, a light source mounting bracket for imaging device one, a light source mounting bracket for imaging device two, a light source mounting slide for imaging device two, a gear ring mounting plate, a gear ring, a receiving part for imaging device one, a receiving part for imaging device two, a sliding plate, a light source part for imaging device two, a light source part for imaging device one, and a guide post. The gear ring mounting plate is mounted on the displacement platform, the gear ring is mounted on the gear ring mounting plate, the sliding plate is mounted on the support rod of the displacement platform, and the guide post is fixed to the displacement platform. The frame is positioned by the guide post and pressed against the sliding plate. The receiving part for imaging device one is mounted on the displacement platform, and the receiver mounting bracket for imaging device one is mounted on... The first receiving part of the imaging device is mounted on the receiving part, the first light source part of the imaging device is mounted on the displacement platform, the first light source mounting bracket is mounted on the first light source part of the imaging device, the second receiving part of the imaging device is mounted on the displacement platform, the second receiver mounting bracket is mounted on the second receiving part of the imaging device, the second receiver mounting slide is mounted on the second receiver mounting bracket, the second light source part of the imaging device is mounted on the displacement platform, the second light source mounting bracket is mounted on the second light source part of the imaging device, and the second light source mounting slide is mounted on the second light source mounting bracket. The first receiving part, the first light source part, the second receiving part, and the second light source part of the imaging device are respectively engaged with the gear ring through rollers.

3. The true triaxial loading testing device for material mechanical properties according to claim 2, characterized in that: The displacement platform includes a first-layer base plate, a second-layer base plate, a third-layer base plate, a support rod, a center hole, first and second-layer support plates, first and second-layer guide rails, first and second-layer sliders, second and third-layer motor adapter plates, second and third-layer motors, second and third-layer support plates, second and third-layer guide rails, second and third-layer sliders, first and second-layer motors, first and second-layer motor adapter plates, and feet. The second and third-layer support plates are mounted on the third-layer base plate, the second and third-layer guide rails are fixed to the second and third-layer support plates, and the second and third-layer sliders are mounted on the second and third-layer guide rails according to the guide rail slider mating method. The second and third-layer motor adapter plates are fixed to the third-layer base plate, and the second and third-layer motors are fixed to the second and third-layer motor adapter plates. The adapter plate serves to move the second-layer base plate. The first and second-layer support plates are installed on the second-layer base plate, and the first and second-layer guide rails are fixed on the first and second-layer support plates. The first and second-layer sliders are installed on the first and second-layer guide rails according to the matching method of the guide rail sliders. The first and second-layer motor adapter plate is fixed on the second-layer base plate, and the first and second-layer motors are fixed on the first and second-layer motor adapter plate. Its function is to move the first-layer base plate. The support electric rod is installed on the third-layer base plate. Its function is to support the frame and realize vertical displacement. The gear ring mounting plate is installed on the first-layer base plate and is concentric with the center hole. The sliding plate is installed on the support electric rod.

4. The true triaxial loading test device for material mechanical properties according to claim 2, characterized in that: The receiving part of the imaging device includes an imaging device receiver angle plate, an imaging device receiver guide rail, an imaging device receiver slider, an imaging device receiver roller, and an imaging device receiver motor. The imaging device receiver angle plate is mounted on a base plate and is concentric with the center hole. The imaging device receiver guide rail is mounted on the imaging device receiver angle plate. The imaging device receiver slider is mounted on the imaging device receiver guide rail. The imaging device receiver mounting bracket is mounted on the imaging device receiver slider. The imaging device receiver motor is mounted at the front end of the imaging device receiver mounting bracket, and its pin is inserted into the pin hole of the imaging device receiver roller, ensuring that the roller meshes with the gear ring. The imaging device's light source component includes an imaging device's light source angle plate, an imaging device's light source guide rail, an imaging device's light source slider, an imaging device's light source roller, and an imaging device's light source motor. The imaging device's light source angle plate is mounted on a base plate and is concentric with the center. The imaging device's light source guide rail is mounted on the imaging device's light source angle plate. The imaging device's light source slider is mounted on the imaging device's light source guide rail. The imaging device's light source mounting bracket is mounted on the imaging device's light source slider. The imaging device's light source motor is mounted at the front end of the imaging device's light source mounting bracket, and its pin is inserted into the pin hole of the imaging device's light source roller, ensuring that the roller meshes with the gear ring.

5. The true triaxial loading test device for material mechanical properties according to claim 2, characterized in that: The receiving part of the imaging device 2 includes an imaging device 2 receiver angle plate, an imaging device 2 receiver guide rail, an imaging device 2 receiver slider, an imaging device 2 receiver roller, and an imaging device 2 receiver motor. The imaging device 2 receiver angle plate is mounted on a base plate and is concentric with the center hole. The imaging device 2 receiver guide rail is mounted on the imaging device 2 receiver angle plate. The imaging device 2 receiver slider is mounted on the imaging device 2 receiver guide rail. The imaging device 2 receiver mounting bracket is mounted on the imaging device 2 receiver slider. The imaging device 2 receiver motor is mounted at the front end of the imaging device 2 receiver mounting bracket, and its pin is inserted into the pin hole of the imaging device 2 receiver roller, ensuring that the imaging device 2 receiver roller meshes with the gear ring. The imaging device 2 receiver mounting slide is mounted on the imaging device 2 receiver mounting bracket. The imaging device's second light source component includes an imaging device second light source angle plate, an imaging device second light source guide rail, an imaging device second light source slider, an imaging device second light source roller, and an imaging device second light source motor. The imaging device second light source angle plate is mounted on a base plate and is concentric with the center hole. The imaging device second light source guide rail is mounted on the imaging device second light source angle plate. The imaging device second light source slider is mounted on the imaging device second light source guide rail. The imaging device second light source mounting bracket is mounted on the imaging device second light source slider. The imaging device second light source motor is mounted at the front end of the imaging device second light source mounting bracket, with its pin inserted into the pin hole of the imaging device second light source roller, ensuring that the imaging device second light source roller meshes with the gear ring. The imaging device second light source mounting slide is mounted on the imaging device second light source mounting bracket.

6. The true triaxial loading testing device for material mechanical properties according to claim 1, characterized in that: The precision rotation module also includes an auxiliary support. The turntable attitude adjustment platform is installed on the upper and lower parts inside the positioning frame of the positioning support module. The precision turntable is installed on the turntable attitude adjustment platform and is coaxial with the center hole reserved on the bottom plate of the displacement platform. By adjusting the turntable attitude adjustment platform, it is coaxial with the precision turntable on the other side. The auxiliary support is installed after the coaxial adjustment is completed and is connected to the precision turntable by adding or removing shims.

7. The true triaxial loading testing device for material mechanical properties according to claim 6, characterized in that: The turntable attitude adjustment platform is fixedly connected above the turntable y-displacement adjustment platform, and the turntable x-displacement adjustment platform is installed below the turntable y-displacement adjustment platform.

8. The true triaxial loading test device for material mechanical properties according to claim 1, characterized in that: The front end of the fixed clamp is designed with threads, and the auxiliary clamp is fixed to the front end of the fixed clamp (30903) by threaded connection.

9. A test method using the true triaxial loading test apparatus for material mechanical properties as described in any one of claims 1 to 8, characterized in that: Includes the following steps: Step 1, Sample clamping: Remove the six mounting clamps from the three loading shafts, fasten the sample to the fixing clamp, fasten the mounting clamps back on and tighten them with screws, and then close the complex working condition simulation module. Step 2: Turn on the imaging module: Turn on the light source and receiver of both imaging devices; Step 3: Static and Dynamic Tensile and Compression Loading: The linear motor actuator is energized to subject the material to static tensile and compression loading or fatigue testing. The stress on any plane of the specimen is analyzed using the following formula: ； ； The maximum applied stress 1, and the component of the maximum stress 1 along the axis in the selected plane is taken as the normal of the selected plane; : Applied intermediate stress 2; : Minimum applied stress 3; The normal stress on any plane of any infinitesimal element in the specimen; The shear stress on any plane of any infinitesimal element in the specimen; :stress The acute angle between the selected plane and the plane; :stress The acute angle between the selected plane and the plane; :stress The acute angle between the selected plane and the plane; :stress and The acute angle between the corresponding component forces when projected onto the selected plane; :stress and The acute angle between the corresponding component forces when projected onto the selected plane; Step 4, Continuous Imaging and Stereoscopic Characterization: Start the precision rotary stage. The rotation of the precision rotary stage drives the static and dynamic loading module to rotate, so that the imaging module can continuously image the sample from 0 to 360°. At the same time, the motors of the imaging device-light source and the imaging device-receiver can be started to adjust the relative positions of the two imaging devices and obtain comparative images from different perspectives. However, during the adjustment, it is necessary to ensure that the corresponding light source and receiver are on the same straight line. Step 5: Shut down the equipment: Keep the experimental data and ensure that all modules are turned off. By comparing the stress analysis results of any plane of the tested material obtained in Step 4 with the image of the tested material obtained in Step 5, the mechanical behavior of the tested material under true triaxial loading can be obtained.

Images