Small beam test piece fatigue test device based on magnetic adsorption

Abstract

The utility model discloses a small beam test piece fatigue test device based on magnetic adsorption, which comprises a base, a first bracket, a first door-shaped frame, a second door-shaped frame, stress loading mechanisms and a power mechanism, the first door-shaped frame and the second door-shaped frame are respectively positioned on the front side and the rear side of the first bracket, and the two stress loading mechanisms are oppositely arranged on the first bracket; the stress loading mechanism comprises an adjusting part, a stress box body, a connecting shaft, a first permanent magnet, a second permanent magnet and a third permanent magnet, the first permanent magnet and the second permanent magnet are located at the same height, the adjusting part is connected with the first permanent magnet and the second permanent magnet, and the third permanent magnet is located on the sides, away from the adjusting part, of the first permanent magnet and the second permanent magnet; and the third permanent magnet is fixedly connected with the connecting shaft. The three permanent magnets are used for loading stress to the small beam test piece, the third permanent magnet is rotated to generate magnetic force, the purpose of applying stress to the small beam test piece is achieved, and the problems that a fatigue test device is large in energy consumption and poor in safety are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of fatigue test, in particular to a fatigue test device for trabecular specimens based on magnetic adsorption. Background Technique

[0002] Due to the high-intensity and frequent action of vehicle loads, the asphalt concrete pavement will show cracking phenomena, and fatigue cracking is one of the most common failure modes of asphalt concrete pavements, seriously affecting the service performance and fatigue performance of the pavement. Therefore, in the process of structural design, construction, maintenance of asphalt pavements, great attention is paid to the problem of fatigue cracking, and corresponding measures are taken for prevention and maintenance. The loading systems of conventional asphalt mixture fatigue test devices mainly adopt pneumatic servo or electro-hydraulic servo to apply periodic loads to specimens; however, due to problems such as large energy consumption, temperature rise, liquid leakage, poor safety, high noise and high maintenance cost in pneumatic drive systems and electro-hydraulic drive systems. Therefore, it is necessary to design an asphalt mixture fatigue test device that saves energy and has high safety. Content of the Utility Model

[0003] The purpose of the utility model is to overcome the deficiencies in the above-mentioned prior art, and provide a fatigue test device for trabecular specimens based on magnetic adsorption. The first permanent magnet, the second permanent magnet and the third permanent magnet are used to apply stress to the trabecular specimen. The first permanent magnet and the second permanent magnet are at the same height, and the third permanent magnet is located on the side of the first permanent magnet and the second permanent magnet away from the adjusting component. Rotating the third permanent magnet generates magnetic force to achieve the purpose of applying stress to the trabecular specimen, and solves the problems of large energy consumption and poor safety of the fatigue test device.

[0004] To achieve the above object, the technical solution adopted by the utility model is as follows: A fatigue test device for trabecular specimens based on magnetic adsorption, comprising a base, a first bracket, a first portal frame and a second portal frame arranged on the base, a stress loading mechanism arranged on the first bracket, and a power mechanism arranged on the base for driving the stress loading mechanism. The first portal frame and the second portal frame are respectively located on the front and rear sides of the first bracket. Trabecular specimens are arranged on the first portal frame and the second portal frame. The number of the stress loading mechanisms is two, and the two stress loading mechanisms are arranged oppositely on the inner sides of the upper part and the lower part of the first bracket. Each of the two stress loading mechanisms includes an adjusting component, a stress box body, a connecting shaft, a first permanent magnet, a second permanent magnet and a third permanent magnet arranged inside the stress box body. The stress box body is connected to the inner wall of the first bracket. The first permanent magnet and the second permanent magnet are at the same height and arranged at intervals in the width direction. The adjusting component is connected to the first permanent magnet and the second permanent magnet for adjusting the positions of the first permanent magnet and the second permanent magnet. The adjusting component is located on the side close to the inner wall of the first bracket. The third permanent magnet is located on the side of the first permanent magnet and the second permanent magnet away from the adjusting component. The end of the third permanent magnet in the length direction is fixedly connected to the connecting shaft.

[0005] Preferably, the adjusting component includes a crank connecting rod, a permanent magnet clamping piece, a lifting shaft and a control turntable. The number of the crank connecting rods and the permanent magnet clamping pieces is two. The two permanent magnet clamping pieces are respectively sleeved on the first permanent magnet and the second permanent magnet. The two crank connecting rods are both in an inverted L-shaped structure. The top of each permanent magnet clamping piece is connected to the end of the vertical part of the crank connecting rod. The ends of the horizontal parts of the two crank connecting rods are arranged oppositely. The connecting rod ends of the two crank connecting rods are rotatably connected to the end of the lifting shaft. The end of the lifting shaft away from the crank connecting rod is fixedly connected to the edge of the control turntable to facilitate the control turntable to drive the crank connecting rod to rotate.

[0006] Preferably, the power mechanism includes a gear meshing and rotating box and a transmission component. The gear meshing and rotating box is connected to the transmission component. The gear meshing and rotating box includes a box body and a first gear, a second gear and a third gear arranged inside the box body. The first gear, the second gear and the third gear are arranged from top to bottom along the height direction of the box body. The second gear is respectively meshed and driven with the first gear and the third gear.

[0007] Preferably, the transmission component includes a variable-speed motor, a transmission shaft, a first rotating shaft, and a second rotating shaft. The output shaft of the variable-speed motor is connected to the end of the transmission shaft. The end of the transmission shaft away from the variable-speed motor is connected to the center of the second gear. The end of the first rotating shaft is connected to the center of the first gear. The end of the first rotating shaft away from the first gear is connected to the connecting shaft on the upper part of the first bracket. The end of the second rotating shaft is connected to the center of the third gear. The end of the second rotating shaft away from the third gear is connected to the connecting shaft on the lower part of the first bracket.

[0008] Preferably, the first bracket includes an outer bracket and an inner bracket. Both the outer bracket and the inner bracket are square structures. The outer bracket is installed on the base. The inner bracket is located inside the outer bracket and can move up and down along the height direction of the outer bracket. The top and bottom of the inner bracket are both iron plates.

[0009] Preferably, the inner bracket includes an inner bracket body, a first cross plate, a second cross plate, a first gasket, a second gasket, and a first bolt. The first cross plate and the second cross plate are horizontally spaced along the height direction of the inner bracket body. The two ends of the first cross plate and the two ends of the second cross plate are respectively connected to the left and right side walls of the inner bracket body. The first gasket is located on the lower side of the first cross plate. The second gasket is installed on the upper side of the second cross plate. The first bolt passes downward through the first cross plate and is connected to the top of the first gasket.

[0010] Preferably, the first gantry and the second gantry have the same structure. The first gantry includes a clamping device, a first support plate, and a second support plate. The clamping device is a square structure and is installed between the first support plate and the second support plate. The first support plate and the second support plate are both square plates and have the same height. The bottoms of the first support plate and the second support plate along the height direction are both fixedly connected to the base.

[0011] Preferably, the clamping device includes a clamping frame body, a second bolt, a pressure sensor, a third gasket, and a fourth gasket. The second bolt passes downward through the top of the clamping frame body and is connected to the third gasket. The pressure sensor is arranged on the inner side of the bottom of the clamping frame body. The fourth gasket is installed on the pressure sensor.

[0012] The utility model has the following advantages compared with the prior art:

[0013] 1. The utility model uses the first permanent magnet, the second permanent magnet, and the third permanent magnet to apply stress to the small beam specimen. The first permanent magnet and the second permanent magnet are at the same height. The third permanent magnet is located on the side of the first permanent magnet and the second permanent magnet away from the adjusting component. Rotating the third permanent magnet generates magnetic force to achieve the purpose of applying stress to the small beam specimen, solving the problems of large energy consumption and poor safety of the fatigue experiment device.

[0014] 2. The positions of the first permanent magnet and the second permanent magnet of the present utility model can be adjusted by an adjusting member, so that the heights of the first permanent magnet and the second permanent magnet rise or fall simultaneously, and the relative positions of the first permanent magnet and the third permanent magnet, and the second permanent magnet and the third permanent magnet change, achieving the purpose of adjusting the maximum stress value.

[0015] 3. Pressure sensors are installed on both the first gantry and the second gantry of the present utility model. The pressure sensors are located on the lower side of the small beam specimen and are used to detect the stress received by the small beam specimen. The stress received by the small beam specimen can be adjusted according to the data detected by the pressure sensors, improving the accuracy of stress loading.

[0016] 4. The present utility model adopts magnetic force loading. The fatigue loading of the small beam specimen is realized through the relative position and rotation of the permanent magnets, avoiding the use of high-precision measuring elements, having a simple structure, and relatively small temperature rise during use.

[0017] The following further describes the present utility model in detail through the drawings and embodiments. Description of the Drawings

[0018] Figure 1 is a schematic structural diagram of the present utility model;

[0019] Figure 2 is a schematic structural diagram inside the stress loading mechanism of the present utility model;

[0020] Figure 3 is a schematic structural diagram inside the gear meshing rotating box of the present utility model;

[0021] Figure 4 is a schematic structural diagram of the inner bracket of the present utility model;

[0022] Figure 5 is a schematic structural diagram of the clamping device of the present utility model;

[0023] Figure 6 is a schematic diagram of the principle of magnetic force sine loading of the present utility model.

[0024] Description of the Reference Numerals:

[0025] 1 - First gantry; 1-1 - Clamping device; 1-2 - First support plate;

[0026] 1-3 - Second support plate; 1-4 - Second bolt; 1-5 - Pressure sensor;

[0027] 1-6 - Third gasket; 1-7 - Fourth gasket; 1-8 - Clamping frame;

[0028] 2 - Second gantry; 3 - Power mechanism; 4 - Outer bracket;

[0029] 5 - Inner stent; 5-1 - Inner stent body; 5-2 - First cross plate;

[0030] 5-3 - Second cross plate; 5-4 - First gasket; 5-5 - Second gasket;

[0031] 5-6 - First bolt; 6 - First bracket; 7 - Stress loading mechanism;

[0032] 7-1 - Stress box; 7-2 - Connecting shaft; 7-3 - First permanent magnet;

[0033] 7-4 - Second permanent magnet; 7-5 - Third permanent magnet; 8 - Trabecular specimen;

[0034] 9 - Gear meshing and rotating box; 9-1 - First gear; 9-2 - Second gear;

[0035] 9-3 - Third gear; 9-4 - Box body; 10 - Transmission component;

[0036] 10-1 - Variable speed motor; 10-2 - Transmission shaft; 10-3 - First rotating shaft;

[0037] 10-4 - Second rotating shaft; 11 - Base; 12 - Adjusting component;

[0038] 12-1 - Crank connecting rod; 12-2 - Permanent magnet clamping part; 12-3 - Lifting shaft;

[0039] 12-4 - Control turntable; 12-5 - Handle. Detailed implementation manners

[0040] Such as Figure 1 、 Figure 2 and Figure 6As shown in the figure, the utility model includes a base 11, a first bracket 6, a first portal frame 1 and a second portal frame 2 arranged on the base 11, a stress loading mechanism 7 arranged on the first bracket 6, and a power mechanism 3 arranged on the base 11 for driving the stress loading mechanism 7. The first portal frame 1 and the second portal frame 2 are respectively located on the front and rear sides of the first bracket 6. A small beam specimen 8 is arranged on the first portal frame 1 and the second portal frame 2. The number of stress loading mechanisms 7 is two. The two stress loading mechanisms 7 are arranged facing each other on the inner sides of the upper part and the lower part of the first bracket 6. Each of the two stress loading mechanisms 7 includes an adjusting component 12, a stress box body 7-1, a connecting shaft 7-2, a first permanent magnet 7-3, a second permanent magnet 7-4, and a third permanent magnet 7-5 arranged inside the stress box body 7-1. The stress box body 7-1 is connected to the inner wall of the first bracket 6. The first permanent magnet 7-3 and the second permanent magnet 7-4 are at the same height and arranged at intervals in the width direction. The adjusting component 12 is connected to the first permanent magnet 7-3 and the second permanent magnet 7-4 for adjusting the positions of the first permanent magnet 7-3 and the second permanent magnet 7-4. The adjusting component 12 is located on the side close to the inner wall of the first bracket 6. The third permanent magnet 7-5 is located on the side of the first permanent magnet 7-3 and the second permanent magnet 7-4 away from the adjusting component 12. The end of the third permanent magnet 7-5 in the length direction is fixedly connected to the connecting shaft 7-2.

[0041] In this embodiment, from left to right along the length direction of the base 11 are the first portal frame 1, the first bracket 6, the second portal frame 2, and the power mechanism 3. The left and right ends of the small beam specimen 8 are respectively installed on the first portal frame 1 and the second portal frame 2. The middle part of the small beam specimen 8 is located on the first bracket 6. The power mechanism 3 drives the stress loading mechanism 7 to generate magnetic force. Since stress loading mechanisms 7 are arranged on both the inner side of the upper part and the inner side of the lower part of the first bracket 6, the two stress loading mechanisms 7 respectively apply upward and downward forces to the small beam specimen 8. The adjusting component 12 can adjust the heights of the first permanent magnet 7-3 and the second permanent magnet 7-4 to adjust the magnitude of the magnetic force generated by the stress loading mechanism 7, facilitating the stress loading mechanism 7 to apply different magnitudes of force to the small beam specimen 8. The maximum value of the magnetic force generated by the two stress loading mechanisms 7 is determined by controlling the distances between the first permanent magnet 7-3 and the third permanent magnet 7-5 and between the second permanent magnet 7-4 and the third permanent magnet 7-5. The two stress loading mechanisms 7 apply sine or partial sine loading forces to the small beam specimen 8 by controlling the rotation of the third permanent magnet 7-5 by the power mechanism 3. The magnitudes of the loading forces generated by the two stress loading mechanisms 7 can be the same or different.

[0042] The third permanent magnet 7-5 in the stress loading mechanism 7 on the inner side of the upper part of the first bracket 6 is located below the first permanent magnet 7-3 and the second permanent magnet 7-4, and the adjusting mechanism 12 is located above the first permanent magnet 7-3 and the second permanent magnet 7-4 and close to the inner wall of the first bracket 6; the third permanent magnet 7-5 in the stress loading mechanism 7 on the inner side of the lower part of the first bracket 6 is located above the first permanent magnet 7-3 and the second permanent magnet 7-4, and the adjusting mechanism 12 is located below the first permanent magnet 7-3 and the second permanent magnet 7-4 and close to the inner wall of the first bracket 6.

[0043] As Figure 2 shown, the adjusting component 12 includes a crank connecting rod 12-1, a permanent magnet clamping member 12-2, a lifting shaft 12-3 and a control turntable 12-4. The number of the crank connecting rods 12-1 and the permanent magnet clamping members 12-2 is two. The two permanent magnet clamping members 12-2 are respectively sleeved on the first permanent magnet 7-3 and the second permanent magnet 7-4. The two crank connecting rods 12-1 are both of an inverted L-shaped structure. The top of each permanent magnet clamping member 12-2 is connected to the end of the vertical end of the crank connecting rod 12-1. The ends of the horizontal ends of the two crank connecting rods 12-1 are arranged facing each other. The connecting rod ends of the two crank connecting rods 12-1 are rotatably connected to the end of the lifting shaft 12-3. The end of the lifting shaft 12-3 away from the crank connecting rod 12-1 is fixedly connected to the edge of the control turntable 12-4 so that the control turntable 12-4 drives the crank connecting rod 12-1 to rotate.

[0044] In this embodiment, the control turntable 12-4 is embedded in the stress box body 7-1, the lifting shaft 12-3 is located inside the stress box body 7-1. A handle 12-5 is installed on one side of the control turntable 12-4 away from the lifting shaft 12-3. The handle 12-5 is located outside the stress box body 7-1 and the handle 12-5 is installed at the edge of the control turntable 12-4. The lifting shaft 12-3 and the handle 12-5 are respectively located at both ends of the diameter of the control turntable 12-4. Hold the handle 12-5 and rotate the control turntable 12-4. The control turntable 12-4 drives the lifting shaft 12-3 to rotate synchronously. The lifting shaft 12-3 drives the two crank connecting rods 12-1 on both sides to move. The two crank connecting rods 12-1 drive the two permanent magnet clamping members 12-2 to rise or fall at the same time. Since the two permanent magnet clamping members 12-2 are respectively sleeved on the first permanent magnet 7-3 and the second permanent magnet 7-4, the two permanent magnet clamping members 12-2 drive the first permanent magnet 7-3 and the second permanent magnet 7-4 to rise and fall synchronously, so that the first permanent magnet 7-3 and the second permanent magnet 7-4 approach or move away from the third permanent magnet 7-5 synchronously, and the maximum value of the magnetic force generated by the stress loading mechanism 7 is reduced or increased.

[0045] As Figure 1 、 Figure 3As shown, the power mechanism 3 includes a gear meshing and rotating box 9 and a transmission component 10. The gear meshing and rotating box 9 is connected to the transmission component 10. The gear meshing and rotating box 9 includes a box body 9-4 and a first gear 9-1, a second gear 9-2, and a third gear 9-3 located inside the box body 9-4. The first gear 9-1, the second gear 9-2, and the third gear 9-3 are arranged from top to bottom along the height direction of the box body 9-4. The second gear 9-2 is in meshing transmission with the first gear 9-1 and the third gear 9-3 respectively.

[0046] As Figure 3 shown, the diameter of the second gear 9-2 is larger than the diameters of the first gear 9-1 and the third gear 9-3. During the rotation of the second gear 9-2, the first gear 9-1 and the third gear 9-3 are driven to rotate synchronously.

[0047] As Figure 1 、 Figure 3 shown, the transmission component 10 includes a variable-speed motor 10-1, a transmission shaft 10-2, a first rotating shaft 10-3, and a second rotating shaft 10-4. The output shaft of the variable-speed motor 10-1 is connected to the end of the transmission shaft 10-2. The end of the transmission shaft 10-2 away from the variable-speed motor 10-1 is connected to the center of the second gear 9-2. The end of the first rotating shaft 10-3 is connected to the center of the first gear 9-1. The end of the first rotating shaft 10-3 away from the first gear 9-1 is connected to the connecting shaft 7-2 on the upper part of the first bracket 6. The end of the second rotating shaft 10-4 is connected to the center of the third gear 9-3. The end of the second rotating shaft 10-4 away from the third gear 9-3 is connected to the connecting shaft 7-2 on the lower part of the first bracket 6.

[0048] In this embodiment, the variable-speed motor 10-1 drives the transmission shaft 10-2 to rotate synchronously. The transmission shaft 10-2 drives the second gear 9-2 to rotate. The second gear 9-2 drives the first gear 9-1 and the third gear 9-3 to rotate synchronously. When the first gear 9-1 rotates, the first rotating shaft 10-3 rotates synchronously and drives the connecting shaft 7-2 on the upper part of the first bracket 6 to rotate. This connecting shaft 7-2 drives the third permanent magnet 7-5 fixedly connected thereto to rotate. When the third gear 9-3 rotates, the second rotating shaft 10-4 rotates synchronously and drives the connecting shaft 7-2 on the lower part of the first bracket 6 to rotate. This connecting shaft 7-2 drives the third permanent magnet 7-5 fixedly connected thereto to rotate. Through the rotation of the third permanent magnet 7-5, cyclic loading forces are generated in the stress loading mechanisms 7 on the inner sides of the upper and lower parts of the first bracket 6, that is, cyclic loading forces of different magnitudes are applied to the small beam specimen 8.

[0049] As Figure 1 、 Figure 4As shown in the figure, the first bracket 6 includes an outer bracket 4 and an inner bracket 5. Both the outer bracket 4 and the inner bracket 5 are square structures. The outer bracket 4 is installed on the base 11. The inner bracket 5 is located inside the outer bracket 4 and can move up and down along the height direction of the outer bracket 4. The top and bottom of the inner bracket 5 are both iron plates.

[0050] In this embodiment, two stress loading mechanisms 7 are respectively installed on the inner sides of the top and bottom of the outer bracket 4. The inner bracket 5 is located inside the outer bracket 4 and between the two opposing stress loading mechanisms 7. A small beam specimen 8 is clamped on the inner bracket 5. The top and bottom of the inner bracket 5 are both iron plates. The magnetic force generated by the stress loading mechanism 7 interacts with the iron plates to achieve the loading of the small beam specimen 8. If it is necessary to adjust the loading forces received by the top and bottom of the small beam specimen 8, the control turntable 12-4 can be rotated by the handle 12-5 to adjust the heights of the first permanent magnet 7-3 and the second permanent magnet 7-4, so as to achieve the purpose of adjusting the maximum value of the loading force.

[0051] As Figure 4 shown in the figure, the inner bracket 5 includes an inner bracket body 5-1, a first cross plate 5-2, a second cross plate 5-3, a first gasket 5-4, a second gasket 5-5 and a first bolt 5-6. The first cross plate 5-2 and the second cross plate 5-3 are both horizontally spaced along the height direction of the inner bracket body 5-1. The two ends of the first cross plate 5-2 and the two ends of the second cross plate 5-3 are respectively connected to the left and right side walls of the inner bracket body 5-1. The first gasket 5-4 is located below the first cross plate 5-2. The second gasket 5-5 is installed on the upper side of the second cross plate 5-3. The first bolt 5-6 passes downward through the first cross plate 5-2 and is connected to the top of the first gasket 5-4.

[0052] In this embodiment, the small beam specimen 8 is located between the first cross plate 5-2 and the second cross plate 5-3. The first cross plate 5-2 is located at the top of the small beam specimen 8, and the second cross plate 5-3 is located at the bottom of the small beam specimen 8. The first bolt 5-6 passes downward through the first cross plate 5-2 and is connected to the first gasket 5-4. A second gasket 5-5 is installed at the contact part between the small beam specimen 8 and the second cross plate 5-3. When it is necessary to fasten the small beam specimen 8, the first bolt 5-6 is screwed downward into the first cross plate 5-2 to make the first gasket 5-4 tightly press against the small beam specimen 8. By screwing the first bolt 5-6 out upward or screwing it in downward, the inner bracket 5 can clamp small beam specimens 8 of different sizes.

[0053] As Figure 1 、 Figure 5As shown, the first portal frame 1 and the second portal frame 2 have the same structure. The first portal frame 1 includes a clamping device 1-1, a first support plate 1-2, and a second support plate 1-3. The clamping device 1-1 is of a square structure and is installed between the first support plate 1-2 and the second support plate 1-3. Both the first support plate 1-2 and the second support plate 1-3 are square plates and have the same height. The bottoms of the first support plate 1-2 and the second support plate 1-3 in the height direction are fixedly connected to the base 11.

[0054] In this embodiment, the clamping device 1-1 is installed at the tops of the first support plate 1-2 and the second support plate 1-3. The first support plate 1-2 is connected to the left side wall of the clamping device 1-1, and the second support plate 1-3 is connected to the right side wall of the clamping device 1-1. The clamping device 1-1 is supported upward by the first support plate 1-2 and the second support plate 1-3, so that the clamping device 1-1 is maintained at a fixed height.

[0055] As Figure 1 、 Figure 5 shown, the clamping device 1-1 includes a clamping frame 1-8, a second bolt 1-4, a pressure sensor 1-5, a third gasket 1-6, and a fourth gasket 1-7. The second bolt 1-4 passes downward through the top of the clamping frame 1-8 and then is connected to the third gasket 1-6. The pressure sensor 1-5 is arranged on the inner side of the bottom of the clamping frame 1-8, and the fourth gasket 1-7 is installed on the pressure sensor 1-5.

[0056] In this embodiment, the first portal frame 1 and the second portal frame 2 are respectively located on the front and rear sides of the first support 6 along the length direction of the base 11. The small beam specimen 8 is installed on the first portal frame 1, the first support 6, and the second portal frame 2. The height of the fourth gasket 1-7 is the same as the height of the second gasket 5-5, so that the small beam specimen 8 is always in a horizontal position. The pressure sensor 1-5 at the bottom of the fourth gasket 1-7 is used to detect the loading force received by the small beam specimen 8. The second bolt 1-4 passes downward through the top of the clamping frame 1-8 and then is connected to the third gasket 1-6. When it is necessary to fasten the small beam specimen 8, the second bolt 1-4 is vertically screwed downward into the clamping frame 1-8, so that the third gasket 1-6 abuts tightly against the small beam specimen 8. By screwing the second bolt 1-4 upward or downward, the clamping device 1-1 can clamp small beam specimens 8 of different sizes.

[0057] During use, first pass the trabecular specimen 8 through the first portal frame 1 and the first support 6 and then reach the second portal frame 2. Screw the first bolt 5-6 on the inner support 5 into the first cross plate 5-2 so that the first gasket 5-4 at the bottom of the first bolt 5-6 abuts tightly against the top of the trabecular specimen 8. Then, screw the clamping devices 1-1 of the first portal frame 1 and the second bolts 1-4 at the tops of the clamping devices 1-1 of the second portal frame 2 downward into the clamping frame body 1-8 so that the third gaskets 1-6 at the bottoms of the second bolts 1-4 abut tightly against the trabecular specimen 8. Thus, the installation of the trabecular specimen 8 is completed. Start the variable-speed motor 10-1, and the variable-speed motor 10-1 drives the transmission shaft 10-2 to rotate synchronously. Under the mutual cooperation of the first gear 9-1, the second gear 9-2, the third gear 9-3, the first rotating shaft 10-3 and the second rotating shaft 10-4, the stress loading mechanisms 7 on the inner sides of the top and bottom of the outer support 4 continuously generate magnetic force. Since the top and bottom of the inner support 5 are both iron plates, under the interaction of the magnetic force generated by the stress loading mechanism 7 and the iron plates, the trabecular specimen 8 continuously receives a loading force. The loading force received by the trabecular specimen 8 is detected by the pressure sensors 1-5 on the first portal frame 1 and the second portal frame 2, which is convenient for judging whether it is necessary to increase or decrease the loading force applied to the trabecular specimen 8, and the fatigue test can be carried out more efficiently.

[0058] The above is only a preferred embodiment of the present invention and does not impose any limitation on the present invention. Any simple modification, change and equivalent structural transformation made to the above embodiments according to the technical essence of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A fatigue test device for trabecular specimens based on magnetic adsorption, characterized in that: It includes a base (11), a first bracket (6), a first portal frame (1) and a second portal frame (2) arranged on the base (11), a stress loading mechanism (7) arranged on the first bracket (6), and a power mechanism (3) arranged on the base (11) for driving the stress loading mechanism (7). The first portal frame (1) and the second portal frame (2) are respectively located on the front and rear sides of the first bracket (6). A small beam specimen (8) is arranged on the first portal frame (1) and the second portal frame (2). The number of the stress loading mechanisms (7) is two, and the two stress loading mechanisms (7) are arranged facing each other on the inner sides of the upper part and the lower part of the first bracket (6). Each of the two stress loading mechanisms (7) includes an adjusting component (12), a stress box body (7-1), and a connecting shaft (7-2), a first permanent magnet (7-3), a second permanent magnet (7-4), and a third permanent magnet (7-5) arranged inside the stress box body (7-1). The stress box body (7-1) is connected to the inner wall of the first bracket (6). The first permanent magnet (7-3) and the second permanent magnet (7-4) are at the same height and arranged at intervals in the width direction. The adjusting component (12) is connected to the first permanent magnet (7-3) and the second permanent magnet (7-4) for adjusting the positions of the first permanent magnet (7-3) and the second permanent magnet (7-4). The adjusting component (12) is located on the side close to the inner wall of the first bracket (6). The third permanent magnet (7-5) is located on the side of the first permanent magnet (7-3) and the second permanent magnet (7-4) away from the adjusting component (12). The end of the third permanent magnet (7-5) along the length direction is fixedly connected to the connecting shaft (7-2).

2. The fatigue test device for trabecular specimens based on magnetic adsorption according to claim 1, characterized in that: The adjusting component (12) includes a crank connecting rod (12-1), a permanent magnet clamping piece (12-2), a lifting shaft (12-3), and a control turntable (12-4). The number of the crank connecting rods (12-1) and the permanent magnet clamping pieces (12-2) is two. The two permanent magnet clamping pieces (12-2) are respectively sleeved on the first permanent magnet (7-3) and the second permanent magnet (7-4). The two crank connecting rods (12-1) are both of an inverted L-shaped structure. The top of each permanent magnet clamping piece (12-2) is connected to the end of the vertical part of the crank connecting rod (12-1). The ends of the horizontal parts of the two crank connecting rods (12-1) are arranged facing each other. The connecting rod ends of the two crank connecting rods (12-1) are rotatably connected to the end of the lifting shaft (12-3). The end of the lifting shaft (12-3) away from the crank connecting rod (12-1) is fixedly connected to the edge of the control turntable (12-4) to facilitate the control turntable (12-4) to drive the crank connecting rod (12-1) to rotate.

3. The fatigue test device for trabecular specimens based on magnetic adsorption according to claim 1, characterized in that: The power mechanism (3) includes a gear meshing and rotating box (9) and a transmission component (10). The gear meshing and rotating box (9) is connected to the transmission component (10). The gear meshing and rotating box (9) includes a box body (9-4) and a first gear (9-1), a second gear (9-2), and a third gear (9-3) located inside the box body (9-4). The first gear (9-1), the second gear (9-2), and the third gear (9-3) are arranged from top to bottom along the height direction of the box body (9-4). The second gear (9-2) is meshed and driven with the first gear (9-1) and the third gear (9-3) respectively.

4. A fatigue test device for trabecular specimens based on magnetic adsorption according to claim 3, characterized in that: The transmission component (10) includes a variable-speed motor (10-1), a transmission shaft (10-2), a first rotating shaft (10-3), and a second rotating shaft (10-4). The output shaft of the variable-speed motor (10-1) is connected to the end of the transmission shaft (10-2). The end of the transmission shaft (10-2) away from the variable-speed motor (10-1) is connected to the center of the second gear (9-2). The end of the first rotating shaft (10-3) is connected to the center of the first gear (9-1). The end of the first rotating shaft (10-3) away from the first gear (9-1) is connected to the connecting shaft (7-2) on the upper part of the first bracket (6). The end of the second rotating shaft (10-4) is connected to the center of the third gear (9-3). The end of the second rotating shaft (10-4) away from the third gear (9-3) is connected to the connecting shaft (7-2) on the lower part of the first bracket (6).

5. A fatigue test device for trabecular specimens based on magnetic adsorption according to claim 1, characterized in that: The first bracket (6) includes an outer bracket (4) and an inner bracket (5). Both the outer bracket (4) and the inner bracket (5) are square structures. The outer bracket (4) is installed on the base (11). The inner bracket (5) is located inside the outer bracket (4) and the inner bracket (5) can move up and down along the height direction of the outer bracket (4). The top and bottom of the inner bracket (5) are both iron plates.

6. The fatigue test device for trabecular specimens based on magnetic adsorption according to claim 5, characterized in that: The inner bracket (5) includes an inner bracket body (5-1), a first cross plate (5-2), a second cross plate (5-3), a first gasket (5-4), a second gasket (5-5), and a first bolt (5-6). The first cross plate (5-2) and the second cross plate (5-3) are horizontally spaced along the height direction of the inner bracket body (5-1). The two ends of the first cross plate (5-2) and the two ends of the second cross plate (5-3) are respectively connected to the left and right side walls of the inner bracket body (5-1). The first gasket (5-4) is located on the lower side of the first cross plate (5-2). The second gasket (5-5) is installed on the upper side of the second cross plate (5-3). The first bolt (5-6) passes through the first cross plate (5-2) downward and is connected to the top of the first gasket (5-4).

7. A fatigue test device for trabecular specimens based on magnetic adsorption according to claim 1, characterized in that: The first portal frame (1) and the second portal frame (2) have the same structure. The first portal frame (1) includes a clamping device (1-1), a first support plate (1-2) and a second support plate (1-3). The clamping device (1-1) is of a square structure and is installed between the first support plate (1-2) and the second support plate (1-3). Both the first support plate (1-2) and the second support plate (1-3) are square plates and have the same height. The bottoms of the first support plate (1-2) and the second support plate (1-3) in the height direction are fixedly connected to the base (11).

8. A fatigue test device for trabecular specimens based on magnetic adsorption according to claim 7, characterized in that: The clamping device (1-1) includes a clamping frame body (1-8), a second bolt (1-4), a pressure sensor (1-5), a third gasket (1-6) and a fourth gasket (1-7). The second bolt (1-4) passes downward through the top of the clamping frame body (1-8) and is connected to the third gasket (1-6). The pressure sensor (1-5) is arranged on the inner side of the bottom of the clamping frame body (1-8). The fourth gasket (1-7) is installed on the pressure sensor (1-5).

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