An impact resistance testing device and method for PC materials

Abstract

This invention relates to the field of pendulum impact testing machine technology, and in particular to a PC material impact resistance testing device and testing method, comprising: a frame, a base, a sample holder, a pendulum arm, a pendulum, a motor, and a sample. The top of the frame is provided with a separation structure, and the sample holder is provided with an automatic fixing structure. The separation structure is used to overcome the reaction force of the motor rotor. The automatic fixing structure automatically fixes the PC material sample by the rotational force generated by the motor. The electromagnetic slider moves outside the electromagnetic slide rail, and the movement of the electromagnetic slide rail causes the motor to move backward. At this time, the insertion rod moves in the slot. After the motor moves, the first gear and the second gear disengage from the meshing state and are not affected by the reaction force, thereby improving the testing accuracy of the pendulum on the sample.

Description

Technical Field

[0001] This invention relates to the field of pendulum impact testing machine technology, and in particular to a device and method for testing the impact resistance of PC materials. Background Technology

[0002] Impact testing of PC materials is conducted to ensure their ability to withstand sudden external impacts in actual use, preventing cracking or breakage under stress, thus guaranteeing product safety and durability. The industry uses pendulum impact testing machines for this purpose. The working principle of the pendulum impact testing machine is based on the law of conservation of energy, determining the material's impact toughness by measuring the potential energy difference before and after the pendulum impacts the specimen. Its working process can be divided into four stages: First, the motor lifts the pendulum to a predetermined height via the transmission system, at which point the pendulum acquires a fixed gravitational potential energy; then, the release mechanism allows the pendulum to fall freely, converting potential energy into kinetic energy, impacting the specimen at maximum speed at the lowest point; after the specimen breaks, the pendulum continues to swing to its highest recovery angle, which is precisely measured by an encoder; finally, the system calculates the energy absorbed by the specimen during fracture based on the difference between the initial angle and the recovery angle, after deducting calibration factors such as bearing friction and air resistance. However, existing pendulum impact testing machines have the following problems.

[0003] (1) The pendulum impact testing machine places the specimen on a sample holder for testing. After being impacted by the pendulum and breaking, the specimen will fly out, and the flying specimen has great kinetic energy, which can easily injure the staff. Existing methods (such as...) Figure 1 As shown, a protective cover 39 is installed on the testing machine to provide protection. However, the existing protective cover is very long and has insufficient space adaptability. In particular, it cannot accommodate the length of the existing protective cover in a small or specially laid-out laboratory environment.

[0004] (2) In existing pendulum impact testing machines, the end of the pendulum arm is usually directly connected to the output shaft of the motor (e.g., Figure 2 As shown, the pendulum arm and pendulum are driven by a motor. During the free fall of the pendulum, the motor is in standby mode. However, because the pendulum drives the motor output shaft to rotate, the coils in the rotor cut the magnetic field lines, generating an induced current. This, in turn, generates an electromagnetic force (reaction force) in the rotor that is opposite to the original magnetic field. This reaction electromagnetic force generates a torque that opposes the rotation of the motor rotor, causing some energy to be consumed. This results in the actual kinetic energy of the pendulum being less than theoretically expected, thus affecting the testing accuracy of the specimen.

[0005] (3) The pendulum of the existing pendulum testing machine has a "fixed moment of inertia". "Fixed moment of inertia" means that the mass distribution of the traditional pendulum and the relationship between the pendulum arm are not adjustable, which means that its dynamic characteristics (such as impact energy and swing period) can only be changed by replacing the entire pendulum or manually adding or removing counterweights, and cannot achieve adaptive adjustment of the pendulum's moment of inertia.

[0006] (4) Existing sample holders are generally fixed by manually rotating the screw. When manually clamping, the operator needs to spend a lot of time and effort to clamp, which is inefficient. It is impossible to use the force of the motor output shaft to drive the sample holder to automatically fix the PC material sample. Summary of the Invention

[0007] The purpose of this invention is to address the shortcomings of the prior art by proposing a device and method for testing the impact resistance of PC materials.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: a PC material impact resistance testing device, comprising: a frame, a base, a sample holder, a swing arm, a pendulum, a motor, and a sample. The top of the frame is provided with a separation structure, and the sample holder is provided with an automatic fixing structure. The separation structure is used to overcome the reaction force of the motor rotor, and the automatic fixing structure automatically fixes the PC material sample by the rotational force generated by the motor.

[0009] As an optional embodiment of the impact resistance testing equipment for PC materials described in this invention, the separation structure includes a groove at the top of the frame, an electromagnetic slide rail installed inside the groove, an electromagnetic slider fixed at the bottom of the motor and slidably connected to the electromagnetic slide rail, a support base fixed at the top of the frame, a rotating shaft rotatably connected to one side of the support base, one end of the rotating shaft fixedly connected to a swing arm, a first gear fixed to the other end of the rotating shaft, a round shaft rotatably connected to the other side of the support base, a second gear fixed to the output shaft of the motor, a plug rod fixed to one end of the second gear, and a slot provided at one end of the round shaft.

[0010] As an optional solution for the impact resistance testing equipment for PC materials described in this invention, the automatic fixing structure includes a winding groove outside the round shaft, in which a steel rope is wound up. Support legs are fixed at the four corners of the bottom of the base, and pads are slidably connected along the support legs. The end of the steel rope passes through the inside of the frame and through the base, and is finally fixedly connected to the pad. A transverse groove runs through the sample holder and the base. A horizontal plate is fixed to the top of the pad, and the top of the horizontal plate passes through the transverse groove to the inside of the sample holder.

[0011] As an optional embodiment of the impact resistance testing equipment for PC materials described in this invention, the sample holder is provided with a placement groove, and two hollow blocks are provided inside the placement groove. The sample holder is provided with a placement groove, and two hollow blocks are fixed inside the placement groove. A movable plate is slidably connected inside the hollow blocks in the horizontal direction. A crossbar is fixed to one end of the movable plate, and a top rod is fixed to one end of the crossbar. The sample holder is provided with a rectangular groove, and the other end of the crossbar is located inside the rectangular groove. The hollow tube and the crossbar are connected by a return spring. An opening is provided on one side of the hollow block.

[0012] As an optional solution of the impact resistance testing equipment for PC materials described in this invention, the pendulum is provided with an inertia adjustment structure, the inertia adjustment structure includes an electric push rod installed inside the end of the pendulum arm, the pendulum has a cavity inside, a counterweight is slidably connected inside the cavity, and the output end of the electric push rod is fixedly connected to the counterweight.

[0013] As an optional solution for the impact resistance testing equipment for PC materials described in this invention, a protective structure is provided on the top of the base. The protective structure includes a winding shaft rotatably connected to the top of the base, with ultra-high molecular weight polyethylene cloth wound around the outside of the winding shaft, and a baffle fixed to one end of the sample holder.

[0014] As an optional embodiment of the impact resistance testing equipment for PC materials described in this invention, the insertion rod is located inside the slot in the initial state, and the first gear meshes with the second gear.

[0015] The impact resistance testing method for PC material is as follows:

[0016] S1: The motor starts and drives the second gear to rotate. The second gear drives the shaft to rotate through the first gear. The shaft drives the swing arm and the pendulum to rotate, thereby raising the pendulum to the predetermined height.

[0017] S2: The separation structure separates the motor's output shaft and rotor from the shaft that drives the pendulum to rotate, thus preventing them from being affected by the reaction force and improving the pendulum's detection accuracy of the sample.

[0018] S3: When the second gear rotates, it will also drive the round shaft to rotate. When the round shaft rotates, the winding groove outside it winds up the steel rope. When the steel rope is wound up, it pulls the pad plate to rise outside the four support legs. The rise of the pad plate drives the vertical rod and wedge block to rise. The rise of the wedge block moves the top rod horizontally to clamp the sample placed in the groove. This process is automated by using the rotational force generated by the motor on the round shaft.

[0019] S4: By adjusting the position of the counterweight by electric push rod, the distribution distance of the mass relative to the axis of rotation is directly changed, thereby adjusting the moment of inertia, optimizing the dynamic response characteristics of the system, improving the stability and control accuracy of the pendulum motion, adapting to different working conditions and test requirements, and improving the applicability and automation level of the equipment.

[0020] S5: When the pendulum swings freely, it passes between the two take-up shafts. Then, when the pendulum swings, it comes into contact with the ultra-high molecular weight polyethylene cloth, which then pulls the ultra-high molecular weight polyethylene cloth out from the outside of the take-up shaft and unfolds to form a protective cover. If the sample breaks, it will be blocked by the protective cover formed by the ultra-high molecular weight polyethylene cloth.

[0021] S6: The system calculates the energy absorbed by the sample during fracture based on the difference between the initial angle and the recovery angle, after deducting calibration factors such as bearing friction and air resistance, thereby enabling the detection of the PC sample.

[0022] The impact resistance testing equipment and method for PC materials proposed in this invention have the following advantages:

[0023] 1. By setting a separation structure, the electromagnetic slider moves outside the electromagnetic slide rail. The movement of the electromagnetic slide rail causes the motor to move backward, and at this time the insertion rod moves in the slot. After the motor moves, the first gear and the second gear disengage from the meshing state. The purpose of the second gear is to lock and limit the engagement of the first gear and drive it to rotate. When the first gear is no longer limited by the second gear, the pendulum falls freely, and the potential energy is converted into kinetic energy. At the lowest point, it impacts the sample at the maximum speed. Since this invention separates the output shaft and rotor of the motor from the shaft that drives the pendulum to rotate, it will not be affected by the reaction force, thereby improving the detection accuracy of the pendulum on the sample and solving the second problem in the background technology.

[0024] 2. Through the automatic fixing structure, when the motor drives the No. 2 gear to rotate, since the insertion rod and the round shaft are connected, the rotation of the No. 2 gear will also drive the round shaft to rotate. When the round shaft rotates, its external winding groove winds up the steel rope. When the steel rope winds up, it pulls the pad, and the pad rises, causing the vertical rod and wedge block to rise in the horizontal groove. The rise of the wedge block forces the movable plate and the top rod to move and clamp the sample. This process uses the rotational force generated by the motor on the round shaft to achieve automatic clamping, thus solving the fourth problem in the background technology.

[0025] 3. By setting up an inertia adjustment structure, since the moment of inertia of the pendulum is proportional to the square of the mass distribution radius, the distribution distance of the mass relative to the axis of rotation can be directly changed by adjusting the position of the counterweight by an electric push rod, thereby adjusting the moment of inertia. This process does not require replacing the entire pendulum or manually adding or removing the counterweight of the pendulum, thus solving the third problem in the background technology.

[0026] 4. Through the protective mechanism, when the pendulum swings freely, it passes between the two winding shafts. Then, when the pendulum swings, it comes into contact with the ultra-high molecular weight polyethylene cloth, which then pulls the ultra-high molecular weight polyethylene cloth out from the outside of the winding shaft and unfolds to form a protective cover. If the sample breaks, it will be blocked by the protective cover formed by the ultra-high molecular weight polyethylene cloth. Attached Figure Description

[0027] Figure 1 This is a front view of the existing pendulum impact testing machine proposed in this invention;

[0028] Figure 2 This is a schematic diagram of the back of a conventional pendulum impact testing machine proposed in this invention;

[0029] Figure 3 This is a front view of the improved pendulum impact testing machine proposed in this invention;

[0030] Figure 4 This is a schematic diagram of the back of the improved pendulum impact testing machine proposed in this invention;

[0031] Figure 5 This is a schematic diagram of the separation structure proposed in this invention;

[0032] Figure 6 The present invention proposes Figure 5 Schematic diagram of a partial structure;

[0033] Figure 7 This is a schematic diagram of the bottom of the base proposed in this invention;

[0034] Figure 8 This is a schematic diagram of the automatic fixing structure proposed in this invention;

[0035] Figure 9 This is a schematic diagram of the internal structure of the hollow block proposed in this invention;

[0036] Figure 10 This is a schematic diagram of the internal structure of the pendulum proposed in this invention;

[0037] Figure 11 This is a schematic diagram of the unfolded ultra-high molecular weight polyethylene fabric proposed in this invention.

[0038] In the diagram: 1. Frame; 2. Base; 3. Sample holder; 4. Swing arm; 5. Pendulum; 6. Motor; 7. Groove; 8. Electromagnetic slide rail; 9. Electromagnetic slider; 10. Support base; 11. Rotating shaft; 12. Gear No. 1; 13. Round shaft; 14. Gear No. 2; 15. Insert rod; 16. Slot; 17. Rewinding groove; 18. Steel rope; 19. Support leg; 20. Pad; 21. Horizontal groove; 23. Placement groove; 25. Hollow block; 29. ​​Movable plate; 30. Crossbar; 31. Return spring; 32. Electric push rod; 33. Cavity; 34. Counterweight; 35. Rewinding shaft; 36. Ultra-high molecular weight polyethylene cloth; 37. Baffle; 38. Sample; 39. Protective cover; 40. Rectangular groove; 41. Vertical rod; 42. Wedge block; 43. Opening; 46. Top rod. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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 are within the scope of protection of the present invention.

[0040] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In the description of this invention, it should be noted that unless otherwise explicitly specified and limited, the terms "installed," "connected," "linked," and "set up" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. The following describes embodiments of the invention based on its overall structure.

[0041] A device and method for testing the impact resistance of PC material includes: a frame 1, a base 2, a sample holder 3, a swing arm 4, a pendulum 5, a motor 6, and a sample 38. The top of the frame 1 has a separation structure, and the sample holder 3 has an automatic fixing structure. The separation structure overcomes the reaction force of the motor 6 rotor, and the automatic fixing structure automatically fixes the PC material sample 38 using the rotational force generated by the motor 6. The separation structure includes a groove 7 on the top of the frame 1, with an electromagnetic slide rail 8 installed inside the groove 7. An electromagnetic slider 9 is fixed to the bottom of the motor 6. The frame 1 is slidably connected to the electromagnetic slide rail 8. A support base 10 is fixed on the top of the frame 1. A rotating shaft 11 is rotatably connected to one side of the support base 10. One end of the rotating shaft 11 is fixedly connected to the swing arm 4. A first gear 12 is fixed to the other end of the rotating shaft 11. A round shaft 13 is rotatably connected to the other side of the support base 10. A second gear 14 is fixed to the output shaft of the motor 6. A plug rod 15 is fixed to one end of the second gear 14. A slot 16 is provided at one end of the round shaft 13. In the initial state, the plug rod 15 is located inside the slot 16, and the first gear 12 meshes with the second gear 14.

[0042] It should be noted that the pendulum 5 is released to fall freely through the separation structure. At this time, the electromagnetic slider 9 moves outside the electromagnetic rail 8. The movement of the electromagnetic rail 8 causes the motor 6 to move backward. At this time, the insertion rod 15 moves in the slot 16. After the motor 6 moves, the first gear 12 and the second gear 14 are separated from the meshing state. The purpose of the second gear 14 is to lock and limit the first gear 12 and drive it to rotate. When the first gear 12 is no longer limited by the second gear 14, the pendulum 5 falls freely, and the potential energy is converted into kinetic energy. At the lowest point, it impacts the sample 38 at the maximum speed. Since the output shaft and rotor of the motor 6 are separated from the rotating shaft 11 that drives the pendulum 5 to rotate, they will not be affected by the reaction force, thereby improving the detection accuracy of the pendulum 5 on the sample 38.

[0043] Furthermore, the automatic fixing structure includes a winding groove 17 on the outside of the round shaft 13, in which a steel rope 18 is wound up. Support legs 19 are fixed at the four corners of the bottom of the base 2, and pads 20 are slidably connected along the support legs 19. The end of the steel rope 18 passes through the inside of the frame 1 and through the base 2, finally being fixedly connected to the pad 20. A horizontal groove 21 runs through the sample holder 3 and the base 2. A vertical rod 41 is fixed to the top of the pad 20, and the top of the vertical rod 41 passes through the horizontal groove 21 to the sample holder. Inside the sample holder 3, a wedge block 42 is fixed to the top of the vertical rod 41. The sample holder 3 is provided with a placement groove 23. Two hollow blocks 25 are fixed inside the placement groove 23. A movable plate 29 is slidably connected inside the hollow block 25 in the horizontal direction. A crossbar 30 is fixed to one end of the movable plate 29. A top rod 46 is fixed to one end of the crossbar 30. The hollow block 25 and the crossbar 30 are connected by a return spring 31. An opening 43 is provided on one side of the hollow block 25.

[0044] Specifically, when the motor 6 drives the second gear 14 to rotate, since the insertion rod 15 is inserted into the round shaft 13, the rotation of the second gear 14 will also drive the round shaft 13 to rotate. When the round shaft 13 rotates, its external winding groove 17 winds up the steel rope 18. When the steel rope 18 winds up, it pulls the pad 20 to rise outside the four support legs 19. The rise of the pad 20 drives the vertical rod 41 to move and rise in the horizontal groove 21. When the vertical rod 41 rises, it carries the wedge block 42 to rise in the rectangular groove 40. When the wedge block 42 rises, it presses one end of the horizontal rod 30. Then the horizontal rod 30 moves with the movable plate 29 and the top rod 46. The movement of the horizontal rod 30 presses the return spring 31. The return spring 31 makes it easy for the horizontal rod 30 to return with the movable plate 29 and the top rod 46 when the wedge block 42 falls. The top rod 46 moves and extends from the opening 43 to achieve multi-point uniform pressure and fixation on the entire surface of the sample 38.

[0045] The next step involves equipping the pendulum 5 with an inertia adjustment structure. This structure includes an electric push rod 32 installed inside the end of the pendulum arm 4. The pendulum 5 has a cavity 33 inside, with a counterweight 34 slidably connected within it. The output end of the electric push rod 32 is fixedly connected to the counterweight 34. Since the moment of inertia of the pendulum 5 is proportional to the square of its mass distribution radius, adjusting the position of the counterweight 34 via the electric push rod 32 directly changes the mass distribution distance relative to the axis of rotation 11, thereby adjusting the moment of inertia. This process eliminates the need to replace the entire pendulum 5 or manually add or remove the counterweight. This automatic inertia adjustment method helps optimize the system's dynamic response characteristics, improves the stability and control accuracy of the pendulum 5's motion, adapts to different working conditions and testing requirements, and enhances the applicability and automation level of the equipment.

[0046] As an example, a protective structure is provided on the top of the base 2. The protective structure includes a winding shaft 35 rotatably connected to the top of the base 2. Ultra-high molecular weight polyethylene cloth 36 is wound around the outside of the winding shaft 35. A baffle 37 is fixed at one end of the sample holder 3. When the pendulum 5 swings freely, it passes between the two winding shafts 35. Then, when the pendulum 5 swings, it contacts the ultra-high molecular weight polyethylene cloth 36, thereby pulling the ultra-high molecular weight polyethylene cloth 36 out from the outside of the winding shaft 35 and unfolding it to form a protective cover. If the sample 38 breaks, it will be blocked by the protective cover formed by the ultra-high molecular weight polyethylene cloth 36 to protect the personnel.

[0047] It is worth emphasizing that UHMWPE 36 has extremely high strength and is lighter than aramid, with excellent impact resistance. It can be used to block high-speed flying metal or composite material fragments, and the flexibility of UHMWPE 36 makes it easy to roll up.

[0048] The impact resistance testing method for PC materials is as follows:

[0049] S1: Motor 6 starts and drives gear 14 to rotate. Gear 14 drives shaft 11 to rotate through gear 12. Shaft 11 drives swing arm 4 and pendulum 5 to rotate, thereby raising pendulum 5 to the predetermined height.

[0050] S2: The separation structure separates the output shaft and rotor of motor 6 from the rotating shaft 11 that drives pendulum 5 to rotate, thus preventing them from being affected by the reaction force and improving the detection accuracy of pendulum 5 on sample 38.

[0051] S3: When the motor 6 drives the second gear 14 to rotate, since the insertion rod 15 is inserted into the round shaft 13, the rotation of the second gear 14 will also drive the round shaft 13 to rotate. When the round shaft 13 rotates, its external winding groove 17 winds up the steel rope 18. When the steel rope 18 winds up, it pulls the pad 20 to rise outside the four support legs 19. The rise of the pad 20 drives the vertical rod 41 and the wedge block 42 to rise. When the wedge block 42 rises, it presses one end of the horizontal rod 30. Then the horizontal rod 30 moves with the movable plate 29 and the top rod 46. The top rod 46 moves and extends from the opening 43 to achieve multi-point fixation of the entire surface of the sample 38. This process uses the rotational force generated by the motor 6 on the round shaft 13 to achieve automated clamping.

[0052] S4: By adjusting the position of the counterweight 34 through the electric push rod 32, the distribution distance of the mass relative to the rotating shaft 11 is directly changed, thereby adjusting the moment of inertia, optimizing the dynamic response characteristics of the system, improving the stability and control accuracy of the pendulum 5 motion, adapting to different working conditions and test requirements, and improving the applicability and automation level of the equipment.

[0053] S5: When the pendulum 5 swings freely, it passes between the two take-up shafts 35. Then, when the pendulum 5 swings, it contacts the ultra-high molecular weight polyethylene cloth 36, and then pulls the ultra-high molecular weight polyethylene cloth 36 out from the outside of the take-up shaft 35 and unfolds to form a protective cover. If the sample 38 breaks, it will be blocked by the protective cover formed by the ultra-high molecular weight polyethylene cloth 36. Then, based on the difference between the initial angle and the recovery angle, after deducting calibration factors such as bearing friction and air resistance, the system calculates the energy absorbed by the sample after fracture, and thus realizes the detection of the PC sample 38.

[0054] Working principle: When the motor 6 starts, it drives the second gear 14 to rotate. The second gear 14 drives the rotating shaft 11 to rotate through the first gear 12. The rotating shaft 11 drives the swing arm 4 and the pendulum 5 to rotate, thereby lifting the pendulum 5 to a predetermined height. At this time, the pendulum 5 obtains a fixed gravitational potential energy.

[0055] The pendulum 5 is released to fall freely through the separation structure. At this time, the electromagnetic slider 9 moves outside the electromagnetic rail 8. The movement of the electromagnetic rail 8 causes the motor 6 to move backward. Meanwhile, the insertion rod 15 moves in the slot 16. After the motor 6 moves, the first gear 12 and the second gear 14 disengage from the meshing state. The purpose of the second gear 14 is to lock and limit the first gear 12 and drive it to rotate. When the first gear 12 is no longer limited by the second gear 14, the pendulum 5 falls freely, and the potential energy is converted into kinetic energy. At the lowest point, it impacts the sample 38 at the maximum speed. Since the output shaft and rotor of the motor 6 are separated from the rotating shaft 11 that drives the pendulum 5 to rotate, they will not be affected by the reaction force, thereby improving the detection accuracy of the pendulum 5 on the sample 38.

[0056] With the automatic fixing structure in place, when motor 6 drives gear 14 to rotate, since the insert rod 15 is connected to the round shaft 13, the rotation of gear 14 also drives the round shaft 13 to rotate. When the round shaft 13 rotates, its external winding groove 17 winds up the steel rope 18. When the steel rope 18 winds up, it pulls the pad 20 to rise outside the four support legs 19. Because motor 6 integrates an electromagnetic brake, when motor 6 is in standby or powered off, the brake will automatically lock the rotating shaft of motor 6, causing it to stop rotating immediately and maintain its position. Therefore, it can prevent the steel rope 18 from loosening and affecting the stability of the pad 20.

[0057] The rise of the pad 20 causes the vertical rod 41 to move and rise within the transverse groove 21. As the vertical rod 41 rises, it carries the wedge block 42 within the rectangular groove 40. The rising wedge block 42 presses against one end of the horizontal rod 30. Then, the horizontal rod 30 moves along with the movable plate 29 and the top rod 46, pressing the return spring 31. The return spring 31 ensures that when the wedge block 42 descends, the horizontal rod 30, along with the movable plate 29 and the top rod 46, returns to its original position. The top rod 46 extends from the opening 43, achieving multi-point uniform pressure and fixation of the entire surface of the sample 38. This multi-point fixation provides a more uniform and stable clamping force, effectively dispersing stress concentration and preventing sample breakage during the fixing process. Excessive local stress can cause prestress, deformation, or damage, thus ensuring that the sample is under initial conditions closer to the actual stress state during impact testing, improving the accuracy of the test results. This process uses the rotational force generated by the motor 6 on the round shaft 13 to achieve automated clamping, and forms a linkage with the lifting action of the drive pendulum 5. When the motor 6 rotates the round shaft 13 in the opposite direction, the winding groove 17 releases the steel rope 18. The lifting effect of the released steel rope 18 on the pad 20 disappears, and then the pad 20 returns to its original position and descends under the action of gravity. After the pad 20 descends, it descends with the wedge block 42. Then, under the action of the return spring 31, the push rod 46 retracts into the hollow block 25, releasing the fixation of the sample 38.

[0058] By utilizing the inertia adjustment structure, since the moment of inertia of the pendulum 5 is proportional to the square of the mass distribution radius, the position of the counterweight 34 can be adjusted via the electric push rod 32 to directly change the mass distribution distance relative to the axis of rotation 11, thereby adjusting the moment of inertia. This process does not require replacing the entire pendulum 5 or manually adding or removing the counterweight. This automatic inertia adjustment method helps optimize the dynamic response characteristics of the system, improves the stability and control accuracy of the pendulum 5's motion, adapts to different working conditions and experimental requirements, and enhances the applicability and automation level of the equipment.

[0059] With the protective mechanism in place, the pendulum 5 swings freely downwards, passing between the two take-up shafts 35. As the pendulum 5 swings, it contacts the ultra-high molecular weight polyethylene (UHMWPE) cloth 36, pulling the UHMWPE cloth 36 out from the outside of the take-up shafts 35 and unfolding it. The baffle 37 is initially attached to the UHMWPE cloth 36, which helps prevent the UHMWPE cloth 36 from adhering to the sample holder 3, changing its shape, and reducing the protection range. At this time, the take-up shafts 35 are rotating, and the unfolded UHMWPE cloth 36... Figure 11 As shown, a protective cover is formed. When the pendulum 5 is lifted upward, the winding shaft 35 automatically winds up the ultra-high molecular weight polyethylene cloth 36. The protective cover formed by the ultra-high molecular weight polyethylene cloth 36 replaces the protective cover 39, and it is small in size and light in weight, making it suitable for narrow terrain.

[0060] The pendulum 5 falls freely and impacts the sample 38. If the sample 38 breaks, it will be blocked by the protective cover formed by the ultra-high molecular weight polyethylene cloth 36. Then, the system calculates the energy absorbed by the sample 38 after deducting calibration factors such as bearing friction and air resistance based on the difference between the initial angle and the recovery angle, thereby realizing the detection of the PC sample 38.

[0061] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. An impact resistance testing device for PC materials, comprising: The machine frame (1), base (2), sample holder (3), swing arm (4), pendulum (5), motor (6), and sample (38) are characterized in that: the top of the machine frame (1) is provided with a separation structure, the sample holder (3) is provided with an automatic fixing structure, the separation structure is used to overcome the reaction force of the rotor of the motor (6), the automatic fixing structure automatically fixes the PC material sample (38) by the rotational force generated by the motor (6), the separation structure includes a groove (7) on the top of the machine frame (1), an electromagnetic slide rail (8) is installed inside the groove (7), an electromagnetic slider (9) is fixed at the bottom of the motor (6), and the electromagnetic slider (9) is slidably connected to the electromagnetic slide rail (8), a support base (10) is fixed at the top of the machine frame (1), a rotating shaft (11) is rotatably connected to one side of the support base (10), one end of the rotating shaft (11) is fixedly connected to the swing arm (4), and a first gear (12) is fixed at the other end of the rotating shaft (11). A round shaft (13) is rotatably connected to the other side of the support base (10). A second gear (14) is fixed to the output shaft of the motor (6). A plug rod (15) is fixed to one end of the second gear (14). A slot (16) is provided at one end of the round shaft (13). The automatic fixing structure includes a winding groove (17) outside the round shaft (13). A steel rope (18) is wound in the winding groove (17). Support legs (19) are fixed at the four corners of the bottom of the base (2). A pad (20) is slidably connected along the support leg (19). The end of the steel rope (18) passes through the inside of the frame (1) and through the base (2) and is finally fixedly connected to the pad (20). The sample holder (3) and the base (2) are connected by a transverse groove (21). A vertical rod (41) is fixed to the top of the pad (20). The top of the vertical rod (41) passes through the transverse groove (21) and comes into the interior of the sample holder (3). A wedge block (42) is fixed to the top of the vertical rod (41).

2. The impact resistance testing equipment for PC materials according to claim 1, characterized in that, The sample holder (3) is provided with a placement groove (23), and two hollow blocks (25) are fixed inside the placement groove (23). A movable plate (29) is slidably connected inside the hollow block (25) in the horizontal direction. A crossbar (30) is fixed at one end of the movable plate (29), and a top rod (46) is fixed at one end of the crossbar (30).

3. The impact resistance testing equipment for PC materials according to claim 2, characterized in that, The sample holder (3) is provided with a rectangular groove (40), and the other end of the crossbar (30) is located inside the rectangular groove (40). The hollow block (25) is connected to the crossbar (30) by a reset spring (31), and an opening (43) is provided on one side of the hollow block (25).

4. The impact resistance testing equipment for PC materials according to claim 3, characterized in that, The pendulum (5) is provided with an inertia adjustment structure, which includes an electric push rod (32) installed inside the end of the pendulum arm (4). The pendulum (5) has a cavity (33) inside, and a counterweight (34) is slidably connected inside the cavity (33). The output end of the electric push rod (32) is fixedly connected to the counterweight (34).

5. The impact resistance testing equipment for PC materials according to claim 4, characterized in that, The base (2) is provided with a protective structure on its top. The protective structure includes a winding shaft (35) rotatably connected to the top of the base (2). Ultra-high molecular weight polyethylene cloth (36) is wound around the outside of the winding shaft (35). A baffle (37) is fixed at one end of the sample holder (3).

6. The impact resistance testing equipment for PC materials according to claim 5, characterized in that, In its initial state, the insert (15) is located inside the slot (16), and the first gear (12) meshes with the second gear (14).

7. The testing method of the PC material impact resistance testing equipment according to claim 6 is as follows: S1: The motor starts and drives the second gear to rotate. The second gear drives the shaft to rotate through the first gear. The shaft drives the swing arm and the pendulum to rotate, thereby raising the pendulum to the predetermined height. S2: The separation structure separates the motor's output shaft and rotor from the shaft that drives the pendulum to rotate, thus preventing them from being affected by the reaction force and improving the pendulum's detection accuracy of the sample. S3: When the second gear rotates, it will also drive the round shaft to rotate. When the round shaft rotates, the winding groove outside it winds up the steel rope. When the steel rope is wound up, it pulls the pad plate to rise outside the four support legs. The rise of the pad plate drives the vertical rod and wedge block to rise. The rise of the wedge block moves the top rod horizontally to clamp the sample placed in the groove. This process is automated by using the rotational force generated by the motor on the round shaft. S4: By adjusting the position of the counterweight by electric push rod, the distribution distance of the mass relative to the axis of rotation is directly changed, thereby adjusting the moment of inertia, optimizing the dynamic response characteristics of the system, improving the stability and control accuracy of the pendulum motion, adapting to different working conditions and test requirements, and improving the applicability and automation level of the equipment. S5: When the pendulum swings freely, it passes between the two take-up shafts. Then, when the pendulum swings, it comes into contact with the ultra-high molecular weight polyethylene cloth, which then pulls the ultra-high molecular weight polyethylene cloth out from the outside of the take-up shaft and unfolds to form a protective cover. If the sample breaks, it will be blocked by the protective cover formed by the ultra-high molecular weight polyethylene cloth. S6: The system calculates the energy absorbed by the sample during fracture based on the difference between the initial angle and the recovery angle, after deducting bearing friction and air resistance calibration factors, thereby realizing the detection of the PC sample.

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