Material impact tester and impact testing method

Abstract

The invention discloses a material impact tester and an impact test method, and the impact tester comprises a support, a hammering rod, a hammer head, an extrusion mechanism, an impact energy adjustment assembly, a lifting assembly, a displacement sensor, a force sensor, and a table top for placing a to-be-tested material. The extrusion mechanism can drive the hammering rod to move downwards so that the hammer head continuously extrudes the to-be-tested material downwards, and the impact energy adjusting assembly is used for controlling the impact load of the hammer head on the to-be-tested material. Before an impact test, the hammering rod can be promoted to extrude the material to be tested through the extruding mechanism, data of the displacement sensor and the force sensor are obtained, the physical property of the material is obtained, the impact load is more accurately and conveniently regulated and controlled through the impact energy adjusting assembly, the application range is wide, the device is particularly suitable for tiny materials, and operation is easy and convenient.

Description

Technical Field

[0001] The present invention relates to the technical field of an impact tester, and in particular to a material impact tester and an impact testing method. Background Art

[0002] The existing sole impact tester has the following problems: 1. Incompleteness of simulated working conditions: Current impact testers use 5J and 7J impact input energies to simulate the impact loads on the soles of shoes during low- and high-speed human movement. However, this method of evaluating the physical properties of structures or materials based on a fixed impact input energy is relatively crude. The physical properties of materials or structures vary with thickness or impact input energy, but existing methods cannot fully test their performance under different working conditions, resulting in incompleteness.

[0003] 2. Limitations of test objects: Existing impact testers for footwear are primarily designed for sole materials, testing the entire sole. This results in high energy input. Directly testing millimeter-sized foam particles (which are tiny materials) can lead to excessive compression or plastic deformation, making it impossible to accurately characterize their energy rebound properties.

[0004] In view of this, the inventor of this case conducted in-depth research, which led to the creation of this case. Summary of the Invention

[0005] The object of the present invention is to provide a material impact tester and an impact testing method that can flexibly and more accurately adjust the impact load (impact energy).

[0006] In order to achieve the above object, the technical solution of the present invention is: A material impact tester comprises a bracket, a hammer drop rod, a hammer head, an extrusion mechanism, an impact energy adjustment component, a lifting component, a displacement sensor, a force sensor, and a table for placing a material to be tested; The bracket is erected on the table, the hammer head is mounted on the bottom of the hammer drop rod, and the hammer drop rod is mounted on the bracket in a manner that it can be raised and lowered; The extrusion mechanism is connected to the hammer drop rod in a manner that it can drive the hammer drop rod to move downward so that the hammer head continuously presses the material to be tested downward; The impact energy adjustment component is a component for regulating the impact load of the hammer head on the material to be tested, the impact energy adjustment component forms a magnetic field area, the impact capacity adjustment component is provided with a current controller for regulating the magnetic field strength of the magnetic field area, and the hammer head is located in the magnetic field area; The lifting assembly and the hammer drop rod are cooperatively connected in a manner that they can be connected to lift the hammer drop rod or separated to release the hammer drop rod; The force sensor is arranged on the hammer head; The displacement sensor is a sensor used to feedback the lifting displacement of the hammer drop rod.

[0007] Furthermore, the impact energy adjustment assembly includes a permanent magnet, a first electromagnetic coil, a second electromagnetic coil and the current controller, the first electromagnetic coil is arranged above the hammer head, the second electromagnetic coil is arranged below the hammer head, the permanent magnet is arranged between the first electromagnetic coil and the second electromagnetic coil, the permanent magnet is located above the force sensor, and the first electromagnetic coil and the second electromagnetic coil are respectively electrically connected to the current controller; The second electromagnetic coil is disposed inside the table.

[0008] Furthermore, the lifting assembly includes a support rod, a turntable and a solenoid valve provided on the support rod, the turntable is connected to the solenoid valve via a connecting rod, one end of the connecting rod is rotatably connected to the turntable, and the other end of the connecting rod is rotatably connected to the solenoid valve; The solenoid valve is provided with a telescopic rod, and the hammer drop rod is provided with a cross bar at a position corresponding to the telescopic rod of the solenoid valve; when the solenoid valve is powered off, the cross bar is connected to the telescopic rod; when the solenoid valve is powered on, the cross bar is disconnected from the telescopic rod. Furthermore, the extrusion mechanism includes a main shaft, a gear, and a variable torque motor that drives the main shaft to rotate, and the gear is mounted on the main shaft through a bearing; An active rod is mounted on the main shaft, and a driven rod is mounted on the gear; a thread meshing with the gear is provided on the hammer drop rod; The main shaft is fixedly connected to a mounting cylinder, wherein a first electromagnetically driven release member and a second electromagnetically driven release member are provided in the mounting cylinder, and are arranged in an upper and lower manner. The second electromagnetically driven release member is fixedly connected to the bottom of the mounting cylinder. The first electromagnetically driven release member is a freely movable block. The active rod is connected to the first electromagnetically driven release member. A return spring is provided between the first and second electromagnetically driven release members. One end of the return spring is fixedly connected to the first electromagnetically driven release member, and the other end is fixedly connected to the second electromagnetically driven release member. The first electromagnetically driven release member and the second electromagnetically driven release member move close to each other when power is supplied, and the active rod moves downward with the first electromagnetically driven release member to be located below the driven rod, and the two are separated. When the first electromagnetically driven release member and the second electromagnetically driven release member are powered off, the return spring resets, the first electromagnetically driven release member and the second electromagnetically driven release member move away from each other, and the active rod moves with the first electromagnetically driven release member to contact the driven rod.

[0009] A material impact testing method using the material impact tester; the impact testing method comprises the following steps: Step S1: Material property testing before impact testing Step S1.1: Place the test material on the table, adjust the hammer until it contacts the test material, control the extrusion mechanism to move the hammer drop rod downward, and then drive the hammer to continuously compress the test material. Obtain data recorded by the displacement sensor and force sensor to obtain stress-strain curve data for the test material. Step S1.2: Calculate the elastic modulus, yield strength, and plastic deformation threshold of the test material using the stress-strain curve data; Step S1.3: Calculate the impact input energy threshold based on the elastic modulus, yield strength, and plastic deformation threshold; Step S2: Impact test Step S2.1: According to the impact input energy threshold value obtained in step S1, the impact load of the material to be tested is adjusted by adjusting the intensity and direction of the magnetic field formed by the impact energy adjustment component; S2.2: The hammer drop rod is lifted to a certain height by the lifting assembly and then released. Under the action of gravity, the hammer drop rod drives the hammer head to impact the material to be tested. The impact is repeated to obtain the recorded data of the displacement sensor and force sensor, and the stress-strain curve data of the test material is obtained. Then, the energy return ratio and shock absorption value are calculated.

[0010] Furthermore, in step S1.2, the elastic modulus E and yield strength are calculated. and plastic deformation threshold ; The elastic modulus E is the stiffness of the material in the elastic stage. ;in :stress, :strain; Yield strength is the minimum stress value at which the material begins to undergo permanent plastic deformation; when calculating, find the end point of the elastic segment, draw the tangent line of the elastic segment, and intersect the tangent line at the obvious bend of the stress-strain curve. The stress corresponding to the intersection is ; Plastic deformation threshold The critical strain value of the material transitioning from elastic deformation to plastic deformation. When calculating, determine the strain corresponding to the yield point. , the plastic deformation threshold is = .

[0011] Furthermore, in step S2, before the impact test, an impact input energy model is first constructed: first, the energy threshold equation is determined: , V = volume of small material, and then calculate the impact energy input range EOPT = [0.2 Emax, 0.8 Emax].

[0012] Furthermore, the extrusion mechanism includes a main shaft, a gear, and a variable torque motor that drives the main shaft to rotate, and the gear is mounted on the main shaft through a bearing; An active rod is mounted on the main shaft, and a driven rod is mounted on the gear; a thread meshing with the gear is provided on the hammer drop rod; The main shaft is fixedly connected to a mounting cylinder, wherein a first electromagnetically driven release member and a second electromagnetically driven release member are provided in the mounting cylinder, the second electromagnetically driven release member being fixedly connected to the bottom of the mounting cylinder, the first electromagnetically driven release member being a freely movable block, the first electromagnetically driven release member being connected to an active rod, a return spring being provided between the first and second electromagnetically driven release members, one end of the return spring being fixedly connected to the first electromagnetically driven release member, and the other end being fixedly connected to the second electromagnetically driven release member; the first and second electromagnetically driven release members move closer to each other when power is applied, the active rod moves downward with the first electromagnetically driven release member to a position below the driven rod, and the active rod separates from the driven rod; when power is removed from the first and second electromagnetically driven release members, the return spring resets, the first and second electromagnetically driven release members move away from each other, and the active rod moves with the first electromagnetically driven release member to contact the driven rod; In step S1.1, first, the first electromagnetically driven release member and the second electromagnetically driven release member are controlled to be in a de-energized state, the return spring resets and holds the first electromagnetically driven release member until the first electromagnetically driven release member and the second electromagnetically driven release member are separated from each other, and the active rod moves along with the first electromagnetically driven release member until it contacts the driven rod; at the same time, the solenoid valve is controlled to be in a energized state, the telescopic rod of the solenoid valve is in a retracted state, and is disconnected from the hammer drop rod; The gear drives the hammer head on the hammer drop rod to squeeze the material to be tested, and the variable torque is output by the variable torque motor to obtain the force-displacement curve data of the material and calculate the impact input energy threshold.

[0013] Furthermore, the impact energy adjustment assembly includes a permanent magnet, a first electromagnetic coil, a second electromagnetic coil and a current controller, wherein the first electromagnetic coil is arranged above the hammer head, the second electromagnetic coil is arranged below the hammer head, the permanent magnet is arranged between the first electromagnetic coil and the second electromagnetic coil, the permanent magnet is located above the force sensor, and the first electromagnetic coil and the second electromagnetic coil are electrically connected to the current controller respectively; The lifting assembly includes a support rod, a turntable and a solenoid valve provided on the support rod, wherein the turntable is connected to the solenoid valve via a connecting rod, one end of the connecting rod is rotatably connected to the turntable, and the other end of the connecting rod is rotatably connected to the solenoid valve; The solenoid valve is provided with a telescopic rod, and the hammer drop rod is provided with a cross bar at a position corresponding to the telescopic rod of the solenoid valve; when the solenoid valve is powered off, the cross bar is connected to the telescopic rod; when the solenoid valve is powered on, the cross bar is disconnected from the telescopic rod.

[0014] Furthermore, during the impact test in step S2, first, the first electromagnetically driven release member and the second electromagnetically driven release member are controlled to be in an energized state, the first electromagnetically driven release member and the second electromagnetically driven release member are attracted to each other, the active rod moves along with the first electromagnetically driven release member until it is separated from the driven rod, and the active rod is located below the driven rod; Secondly, the drive motor of the turntable is controlled to rotate, thereby driving the turntable to rotate, and then driving the connecting rod to drive the solenoid valve to move up and down repeatedly: When the hammer drop rod is about to rise, the solenoid valve is controlled to be in a power-off state, the telescopic rod is extended to a state combined with the cross bar, and the cross bar and the hammer drop rod are lifted and moved upward by the telescopic rod. When the hammer drop rod rises to a certain height, the solenoid valve is controlled to be in a power-on state, the telescopic rod is retracted and disconnected from the hammer drop rod. Under the action of gravity, the hammer drop rod causes a hammer to fall and hammer the test material. This operation is repeated to achieve repeated impacts on the material to be tested.

[0015] By adopting the above technical solution, the present invention provides a material impact tester with the following beneficial effects: Before the impact test, a compression mechanism drives the hammer to continuously compress the material to be tested, and the displacement sensor and force sensor cooperate to obtain the material's physical properties. Based on the material's physical properties, the impact energy adjustment component then provides more precise, flexible, and convenient control (through current manipulation) of the impact load. This instrument has a wide range of applications, particularly for testing tiny materials, and is simple and convenient to operate.

[0016] The material impact tester has the following benefits: (1) The magnetic field strength can be adjusted to a smaller impact load by adjusting the current, which can meet the impact test requirements of tiny materials.

[0017] (2) Pre-measure the material properties and calculate the impact input energy threshold. Compared with the traditional fixed impact input energy, this method is more in line with material testing requirements. It overcomes the problems of traditional fixed energy input, such as inconvenient adjustment, poor operability, and poor adjustment accuracy.

[0018] (3) By adjusting the impact input energy through magnetic force, the energy return curve of the material can be output instead of an energy return value output by traditional testing instruments. This can reflect the energy return performance of the material under different working conditions, and the data is more comprehensive.

[0019] The invention also discloses a material impact testing method. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the structure of the material impact tester of the present invention (omitting the main shaft, gear, first magnet, second magnet, etc.); Figure 2 It is a structural schematic diagram of the first magnet and the second magnet of the present invention in a state of being separated from each other; Figure 3 It is a structural schematic diagram of the first magnet and the second magnet in the state of attraction between each other of the present invention; Figure 4 It is a structural schematic diagram of the installation cylinder in the present invention; Figure 5 Schematic diagram of the relative position structure of the hammer drop rod and the displacement sensor in the present invention; Figure 6 This is a schematic diagram of the installation structure of the mechanical sensor in the present invention.

[0021] In the picture: Hammer drop rod 01; threaded section 011; hammer head 02; displacement sensor 03; disk 031; force sensor 04; bracket 05; permanent magnet 06; first electromagnetic coil 07; second electromagnetic coil 08; current controller 09; gear 10; bearing 11; main shaft 12; motor 121; Active rod 13; driven rod 14; mounting cylinder 15; first magnet 16; Second magnet 17; return spring 18; support rod 19; turntable 20; solenoid valve 21; telescopic rod 22; crossbar 23; connecting rod 24; motor 25; table 26; strip groove 27; DETAILED DESCRIPTION Example 1 The present invention provides a material impact tester that can be used for impact testing of tiny materials (such as millimeter-sized foam particles, etc.). The following is an example of tiny materials. Figures 1 to 6 As shown, it includes a hammer drop rod 01, a hammer head 02, an extrusion mechanism, an impact energy adjustment component, a lifting component, a displacement sensor 03, a force sensor 04 and a bracket 05. The hammer head 02 is installed at the bottom of the hammer drop rod 01, and the hammer drop rod 01 is installed on the bracket 05 in a liftable manner. The force sensor 04 is arranged on the hammer head 02, and the displacement sensor 03 is installed on the bracket 05.

[0022] The extrusion mechanism is connected to the hammer drop rod 01 by transmission, driving the hammer drop rod 01 to move downward, and then the hammer head 02 continuously presses the material to be tested downward.

[0023] The impact energy adjustment component is a component for controlling the impact load of the hammer head on the material to be tested. The impact capacity adjustment component forms a magnetic field zone. The impact capacity adjustment component is provided with a current controller 09 for adjusting the magnetic field strength of the magnetic field zone. The hammer head 02 is located in the magnetic field zone.

[0024] The lifting assembly is a component used to lift and release the hammer drop rod 01; the lifting assembly and the hammer drop rod 01 are connected in a manner that they can be connected to lift the hammer drop rod 01 or separated to release the hammer drop rod 01.

[0025] The force sensor 04 is provided on the hammer head 02; The displacement sensor 03 is a sensor used to feedback the lifting and lowering displacement of the hammer drop rod.

[0026] Specifically, the impact energy adjustment assembly includes a permanent magnet 06, a first electromagnetic coil 07, a second electromagnetic coil 08, and a current controller 09. The first electromagnetic coil 07 is positioned above the hammer 02, while the second electromagnetic coil 08 is positioned below the hammer 02. The permanent magnet 06 is positioned between the first and second electromagnetic coils 07 and 08, and each is electrically connected to the current controller 09. Specifically, the permanent magnet 06 is positioned above and adjacent to the force sensor 04, with the upper pole of the permanent magnet 06 being the north pole and the lower pole being the south pole. The current controller 09 controls the direction, magnitude, and frequency of the current flowing through the corresponding electromagnetic coils, thereby controlling the direction and strength of the uniform magnetic field between the coils. This uniform magnetic field can accelerate or decelerate the falling permanent magnet 06 depending on its direction, thereby varying the impact energy of the hammer 02 on the tiny particles under the control of the current controller 09.

[0027] The present invention relates to a micro-material impact tester. In view of the fact that traditional impact testers are inconvenient to adjust the impact load (i.e., impact energy), have problems such as poor adjustment accuracy and poor adjustment operability, this case has innovatively designed a tester that can be used for impact testing of micro-materials (such as millimeter-sized foam particles, etc.).

[0028] It should be noted that the micro-material impact tester of the present invention is not only suitable for impact testing of micro-materials, but also suitable for testing non-micro-materials such as soles.

[0029] Before the impact test, the hammer head 02 contacts the material to be tested. The extrusion mechanism drives the hammer drop rod downward, causing the hammer head to continuously press the material downward. Data from the displacement sensor 03 and force sensor 04 are acquired to determine the material's physical properties. Based on these properties, the impact energy adjustment assembly (a uniform magnetic field is generated between the first and second electromagnetic coils 07 and 08, and the permanent magnet 06 is subjected to an upward or downward magnetic force) precisely and conveniently controls the impact load. This device has a wide range of applications, particularly for micro-materials, and offers simple and convenient operation.

[0030] As a preferred embodiment, refer to Figure 2 and Figure 3 As shown, the hammer drop lever 01 is provided with a threaded segment 011, which is mounted with a gear 10. Gear 10 is mounted on a spindle 12 via a bearing 11. A motor 121 is mounted on the spindle 12. Specifically, motor 121 is mounted on the top of spindle 12. Spindle 12 and hammer drop lever 01 are arranged vertically side by side. In the present invention, the spindle 12 and gear 10 are positioned to achieve their respective functions. Motor 121 can be fixed to bracket 05.

[0031] An active rod 13 is vertically mounted on the main shaft 12 (horizontally), and a driven rod 14 is vertically mounted on the gear 10 (vertically). The active rod 13 and the driven rod 14 are arranged perpendicularly.

[0032] The main shaft 12 is fixedly connected to a mounting cylinder 15 , in which a first electromagnetically driven release member and a second electromagnetically driven release member are mounted. The first electromagnetically driven release member is specifically a first magnet 16 , and the second electromagnetically driven release member is specifically a second magnet 17 .

[0033] Second magnet 17 is fixedly connected to the bottom of mounting tube 15, while first magnet 16 is a free-moving block. Mounting tube 15 has a vertical slot 27 defined therein. One end of active rod 13 is fixedly connected to first magnet 16, while the other end extends from slot 27. A return spring 18 is located between first magnet 16 and second magnet 17. One end of return spring 18 is fixedly connected to first magnet 16, and the other end is fixedly connected to second magnet 17. When the power is on, the first magnet 16 and the second magnet 17 move closer to each other, the active rod 13 is located below the driven rod 14, and the two are separated (the separation distance between the two needs to be greater than the hammer drop distance of the subsequent impact test so as not to affect the repeated hammer test); when the first magnet 16 and the second magnet 17 are not powered, the reset spring 18 resets and supports the first magnet 16 until the first magnet 16 and the second magnet 17 are separated, and the active rod 13 moves with the first magnet 16 to be perpendicular to and in contact with the driven rod 14. When the active rod 13 rotates circumferentially with the main shaft 12, it can push the driven rod 14 to drive the gear 10 to rotate circumferentially, thereby driving the movement of the hammer drop rod 01.

[0034] In this way, the first magnet 16 can be controlled to move toward or away from the second magnet 17 by controlling whether the power is on. The movement of the first magnet 16 drives the movement of the active rod 13, thereby controlling whether the active rod 13 contacts the driven rod 14. This in turn controls whether the driven rod 14 rotates with the active rod 13 (motor 121), thereby controlling the movement of the hammer drop rod 01. Specifically, the rotation of the motor 121 controls the descent of the hammer drop rod 01 to squeeze the material to be tested.

[0035] As a preferred embodiment, the micro-material impact tester further includes a lifting component.

[0036] refer to Figure 1 As shown, the lifting assembly includes a support rod 19 , and a turntable 20 and a solenoid valve 21 arranged on the support rod 19 . The turntable 20 is arranged at the top of the support rod 19 , and the solenoid valve 21 is arranged in the middle of the support rod 19 .

[0037] The turntable 20 is connected to the solenoid valve 21 through a connecting rod 24. One end of the connecting rod 24 is rotatably connected to the turntable 20, and the other end of the connecting rod 24 is rotatably connected to the solenoid valve 21. When the turntable 20 rotates, the height of the solenoid valve 21 can be raised.

[0038] Solenoid valve 21 is equipped with a telescopic rod 22, and hammer drop rod 01 is equipped with a crossbar 23 at the position corresponding to the telescopic rod 22 of solenoid valve 21. When the power is off, the telescopic rod 22 of solenoid valve 21 extends, and the crossbar 23 is connected to the telescopic rod 22. The telescopic rod 22 stops the crossbar 23, limiting the crossbar 23 and preventing the hammer drop rod 01 with the crossbar 23 from falling due to gravity. When the power is on, the telescopic rod 22 of solenoid valve 21 retracts (shortens), and the crossbar 23 is disconnected from the telescopic rod 22. The crossbar 23 is no longer restrained, and the hammer drop rod 01 can fall due to gravity.

[0039] During the impact test, the rotation of the turntable 20 raises the solenoid valve 21. During this period, the solenoid valve 21 remains de-energized, and the telescopic rod 22 extends to engage with the crossbar 23, lifting the hammer drop rod 01 via the crossbar 23. When the hammer drop rod 01 reaches the set height, the solenoid valve 21 is energized, the telescopic rod 22 retracts, and the hammer drop rod 01 drops, striking the test material. After the impact, the turntable 20 rotates again, ultimately driving the solenoid valve 21 back and forth via the connecting rod 24, ultimately achieving the reciprocating impact of the hammer drop rod 01.

[0040] The turntable 20 is driven to rotate by the motor 25 , and the rotation of the turntable 20 drives the connecting rod 24 and further drives the solenoid valve 21 to perform a reciprocating impact motion.

[0041] As a preferred embodiment, the second electromagnetic coil 08 is disposed inside the (impact) table 26 .

[0042] As a preferred embodiment, Figure 5 As shown, displacement sensor 03 is set corresponding to hammer drop rod 01. Displacement sensor 03 has a disk 031. Disk 031 touches hammer drop rod 01. When hammer drop rod 01 moves, it drives disk 031 to rotate. Displacement sensor 03 converts the number of rotations of disk 031 into displacement.

[0043] It should be noted that, in the present invention, the displacement sensor 03 and the force sensor 04 are both conventional components in the industry, as long as they can achieve corresponding functions, and are not limited here.

[0044] The material impact tester has the following benefits: (1) According to the impact input energy threshold, the current of the current controller is regulated to control the magnetic field strength. It has good flexibility, high precision, and a large adjustable range, which can meet the impact test requirements of tiny materials.

[0045] (2) Pre-measure the material properties and calculate the impact input energy threshold. Compared with the traditional fixed impact input energy, this method is more in line with material testing requirements. It overcomes the problems of traditional fixed energy input, such as inconvenient adjustment, poor operability, and poor adjustment accuracy.

[0046] (3) By adjusting the impact input energy through magnetic force, the energy return curve of the material can be output instead of an energy return value output by traditional testing instruments. This can reflect the energy return performance of the material under different working conditions, and the data is more comprehensive.

[0047] Example 2 The present invention provides a method for impact testing of micro materials, comprising the following steps: Step S1: Material property testing before impact testing Step S1.1: First, place the test material on the table, adjust the hammer head 02 to the test material, control the extrusion mechanism to drive the hammer drop rod to move downward, and then drive the hammer head to continuously squeeze the test material. The motor 121 outputs a variable torque, obtains the recorded data of the displacement sensor 03 and the force sensor 04, and obtains the stress-strain curve data of the test material; Step S1.2: Calculate the elastic modulus, yield strength, and plastic deformation threshold of the test material using the stress-strain curve data; Step S1.3: Calculate the impact input energy threshold based on the elastic modulus, yield strength, and plastic deformation threshold; Specifically, by compressing tiny materials, the stress-strain curve is obtained, and the elastic modulus E and yield strength are calculated. , plastic deformation threshold .

[0048] a) Elastic modulus E: The stiffness of a material in the elastic stage (stress is proportional to strain), reflecting the material's ability to resist elastic deformation.

[0049] Calculation formula: ;in :stress, :strain; b) Yield strength : The minimum stress value at which the material begins to undergo permanent plastic deformation.

[0050] Calculation method: Find the end point of the elastic segment (the position where the slope of the stress-strain curve begins to decrease), draw a tangent line to the elastic segment, and intersect it with the tangent line at the obvious bend of the curve. The stress corresponding to the intersection is .

[0051] c) Plastic deformation threshold : The critical strain value at which the material transitions from elastic deformation to plastic deformation.

[0052] Calculation method: Determine the strain corresponding to the yield point , the plastic deformation threshold is =

[0053] Step S2: Impact test Step S2.1 Construction of impact input energy model a) Determine the energy threshold equation: , V = volume of tiny material; b) Calculate the impact energy input range: EOPT = [0.2 Emax, 0.8 Emax] Step S2.2: Impact operation Step S2.1: According to the impact input energy threshold value obtained in step S1, the impact load of the material to be tested is adjusted by adjusting the intensity and direction of the magnetic field formed by the impact energy adjustment component; Specifically, according to the impact input energy threshold, the current of the current controller is regulated to control the magnetic field strength. The permanent magnet is subjected to an upward or downward magnetic force in the uniform magnetic field formed between the first electromagnetic coil and the second electromagnetic coil, thereby controlling the impact load (i.e., impact energy) of the hammer head on the test material.

[0054] S2.2: The hammer drop rod is lifted to a certain height by the lifting assembly and then released. Under the action of gravity, the hammer drop rod drives the hammer head to impact the material to be tested. The impact is repeated to obtain the recorded data of the displacement sensor and force sensor, and the stress-strain curve data of the test material is obtained. Then, the energy return ratio and shock absorption value are calculated.

[0055] In step S1.1, first, the first magnet 16 and the second magnet 17 are controlled to be in the power-off state, the reset spring 18 resets and supports the first magnet 16 until the first magnet 16 and the second magnet 17 are away from each other, and the active rod 13 moves with the first magnet 16 to be perpendicular to and in contact with the driven rod 14; (at the same time, the solenoid valve 21 of the lifting assembly must be controlled to be in the power-on state, the telescopic rod 22 is in the retracted state, and is disconnected from the hammer drop rod 01). Secondly, the hammer drop rod 01 is controlled to squeeze the material to be tested: the gear 10 drives the hammer head 02 on the hammer drop rod 01 to squeeze the material to be tested, and the variable torque is output through the variable torque motor 121 to obtain the force-displacement curve data of the material and calculate the impact input energy threshold.

[0056] During the impact test in step S2, first, the first magnet 16 and the second magnet 17 are controlled to be in an energized state, the first magnet 16 and the second magnet 17 are attracted to each other, and the active rod 13 moves along with the first magnet 16 until it is separated from the driven rod 14, and the active rod 13 is located below the driven rod 14; Secondly, the control motor 25 rotates, driving the turntable 20 to rotate, and then driving the connecting rod 24 to drive the solenoid valve 21 to move up and down repeatedly; When the hammer drop rod 01 is about to rise, the control solenoid valve 21 is in the de-energized state, and the telescopic rod 22 is in the state of extending to the limit position combined with the cross bar 23. The telescopic rod 22 pulls the cross bar 23 and the hammer drop rod 01 to move upward; when the hammer drop rod 01 rises to a certain height, the control solenoid valve 21 is in the energized state, and the telescopic rod 22 is in the retracted state, disconnected from the hammer drop rod 01, and the hammer drop rod 01 falls under the action of gravity, hammering the test material. This operation is repeated to achieve repeated impact on the material to be tested.

[0057] The above embodiments and drawings do not limit the product form and style of the present invention. Any appropriate changes or modifications made by ordinary technicians in the relevant technical field should be deemed to be within the patent scope of the present invention.

Claims

1. A material impact tester, characterized in that: It includes a bracket, a hammer drop rod, a hammer head, an extrusion mechanism, an impact energy adjustment component, a lifting component, a displacement sensor, a force sensor, and a table for placing the material to be tested; The bracket is erected on the table, the hammer head is mounted on the bottom of the hammer drop rod, and the hammer drop rod is mounted on the bracket in a manner that it can be raised and lowered; The extrusion mechanism drives the hammer drop rod to move downward so that the hammer head continues to squeeze the material to be tested downward; The impact energy adjustment component is used to adjust the impact load of the hammer head on the material to be tested; The lifting assembly and the hammer drop rod are cooperatively connected in a manner that they can be connected to lift the hammer drop rod or separated to release the hammer drop rod; The force sensor is arranged on the hammer head; The displacement sensor is a sensor used to feedback the lifting displacement of the hammer drop rod.

2. A material impact tester according to claim 1, characterized in that: The impact energy adjustment component forms a magnetic field zone, and the impact energy adjustment component includes a current controller for adjusting the magnetic field strength of the magnetic field zone, and the hammer head is located in the magnetic field zone.

3. A material impact tester according to claim 2, characterized in that: The impact energy adjustment component includes a permanent magnet, a first electromagnetic coil, a second electromagnetic coil and the current controller, the first electromagnetic coil is arranged above the hammer head, the second electromagnetic coil is arranged below the hammer head, the permanent magnet is arranged between the first electromagnetic coil and the second electromagnetic coil, the permanent magnet is located above the force sensor, and the first electromagnetic coil and the second electromagnetic coil are electrically connected to the current controller respectively.

4. A material impact tester according to claim 1, characterized in that: The lifting assembly includes a support rod, a turntable and a solenoid valve arranged on the support rod, the turntable is connected to the solenoid valve through a connecting rod, one end of the connecting rod is rotatably connected to the turntable, and the other end of the connecting rod is rotatably connected to the solenoid valve. The solenoid valve is provided with a telescopic rod, and the hammer drop rod is provided with a cross bar at a position corresponding to the telescopic rod of the solenoid valve; when the solenoid valve is powered off, the cross bar is connected to the telescopic rod; when the solenoid valve is powered on, the cross bar is disconnected from the telescopic rod.

5. A material impact tester according to claim 1, characterized in that: The extrusion mechanism includes a main shaft, a gear and a variable torque motor that drives the main shaft to rotate, and the gear is installed on the main shaft through a bearing; An active rod is mounted on the main shaft, and a driven rod is mounted on the gear; a thread meshing with the gear is provided on the hammer drop rod; The main shaft is fixedly connected to a mounting cylinder, wherein a first electromagnetically driven release member and a second electromagnetically driven release member are provided in the mounting cylinder, and are arranged in an upper and lower manner. The second electromagnetically driven release member is fixedly connected to the bottom of the mounting cylinder. The first electromagnetically driven release member is a freely movable block. The active rod is connected to the first electromagnetically driven release member. A return spring is provided between the first and second electromagnetically driven release members. One end of the return spring is fixedly connected to the first electromagnetically driven release member, and the other end is fixedly connected to the second electromagnetically driven release member. The first electromagnetically driven release member and the second electromagnetically driven release member move close to each other when power is supplied, and the active rod moves downward with the first electromagnetically driven release member to be located below the driven rod, and the two are separated. When the first electromagnetically driven release member and the second electromagnetically driven release member are powered off, the return spring resets, the first electromagnetically driven release member and the second electromagnetically driven release member move away from each other, and the active rod moves with the first electromagnetically driven release member to contact the driven rod.

6. A method for impact testing a material, characterized in that: Using the material impact tester according to claims 1 to 5; the impact testing method comprises the following steps: Step S1: Material property testing before impact testing Step S1.1: Place the test material on the table, adjust the hammer until it contacts the test material, control the extrusion mechanism to move the hammer drop rod downward, and then drive the hammer to continuously compress the test material. Obtain data recorded by the displacement sensor and force sensor to obtain stress-strain curve data for the test material. Step S1.2: Calculate the elastic modulus, yield strength, and plastic deformation threshold of the test material using the stress-strain curve data; Step S1.3: Calculate the impact input energy threshold based on the elastic modulus, yield strength, and plastic deformation threshold; Step S2: Impact test Step S2.1: According to the impact input energy threshold value obtained in step S1, the impact load of the material to be tested is adjusted by adjusting the intensity and direction of the magnetic field formed by the impact energy adjustment component; S2.2: The hammer drop rod is lifted to a certain height by the lifting assembly and then released. Under the action of gravity, the hammer drop rod drives the hammer head to impact the material to be tested. The impact is repeated to obtain the recorded data of the displacement sensor and force sensor, and the stress-strain curve data of the test material is obtained. Then, the energy return ratio and shock absorption value are calculated.

7. The impact testing method for a material according to claim 6, wherein: In step S1.2, calculate the elastic modulus E and yield strength and plastic deformation threshold ; The elastic modulus E is the stiffness of the material in the elastic stage. ; :stress, :strain; Yield strength It is the minimum stress value at which the material begins to undergo permanent plastic deformation; When calculating, find the end point of the elastic segment, draw the tangent line of the elastic segment, and intersect the tangent line at the obvious bend of the stress-strain curve. The stress corresponding to the intersection is ; Plastic deformation threshold The critical strain value of the material transitioning from elastic deformation to plastic deformation. When calculating, determine the strain corresponding to the yield point. , the plastic deformation threshold is = .

8. The impact testing method for a material according to claim 7, wherein: In step S2, before the shock test, the shock input energy model is constructed: first, the energy threshold equation is determined: , V = volume of small material, and then calculate the impact energy input range EOPT = [0.2 Emax, 0.8 Emax].

9. The impact testing method for a material according to claim 6, wherein: The extrusion mechanism includes a main shaft, a gear, and a variable torque motor that drives the main shaft to rotate, and the gear is installed on the main shaft through a bearing; An active rod is mounted on the main shaft, and a driven rod is mounted on the gear; a thread meshing with the gear is provided on the hammer drop rod; The main shaft is fixedly connected to a mounting cylinder, wherein a first electromagnetically driven release member and a second electromagnetically driven release member are provided in the mounting cylinder, the first electromagnetically driven release member being fixedly connected to the bottom of the mounting cylinder, the first electromagnetically driven release member being a freely movable block, the first electromagnetically driven release member being connected to an active rod, a return spring being provided between the first and second electromagnetically driven release members, one end of the return spring being fixedly connected to the first electromagnetically driven release member, and the other end being fixedly connected to the second electromagnetically driven release member; When the first electromagnetically driven release member and the second electromagnetically driven release member are energized, they move toward each other, and the active rod moves downward along with the first electromagnetically driven release member to be located below the driven rod, and the active rod and the driven rod are separated. When the first electromagnetically driven release member and the second electromagnetically driven release member are de-energized, the return spring returns to its original position, and the first electromagnetically driven release member and the second electromagnetically driven release member move away from each other, and the active rod moves along with the first electromagnetically driven release member to contact the driven rod. In step S1.1, first, the first electromagnetically driven release member and the second electromagnetically driven release member are controlled to be in a de-energized state, the return spring resets and holds the first electromagnetically driven release member until the first electromagnetically driven release member and the second electromagnetically driven release member are separated from each other, and the active rod moves along with the first electromagnetically driven release member until it contacts the driven rod; at the same time, the solenoid valve is controlled to be in a energized state, the telescopic rod of the solenoid valve is in a retracted state, and is disconnected from the hammer drop rod; The gear drives the hammer head on the hammer drop rod to squeeze the material to be tested, and the variable torque is output by the variable torque motor to obtain the force-displacement curve data of the material and calculate the impact input energy threshold.

10. The impact testing method for a material according to claim 6, wherein: The impact energy adjustment assembly includes a permanent magnet, a first electromagnetic coil, a second electromagnetic coil and a current controller, wherein the first electromagnetic coil is arranged above the hammer head, the second electromagnetic coil is arranged below the hammer head, the permanent magnet is arranged between the first electromagnetic coil and the second electromagnetic coil, the permanent magnet is located above the force sensor, and the first electromagnetic coil and the second electromagnetic coil are electrically connected to the current controller respectively; The lifting assembly includes a support rod, a turntable and a solenoid valve provided on the support rod, wherein the turntable is connected to the solenoid valve via a connecting rod, one end of the connecting rod is rotatably connected to the turntable, and the other end of the connecting rod is rotatably connected to the solenoid valve; The solenoid valve is provided with a telescopic rod, and the hammer drop rod is provided with a cross bar at a position corresponding to the telescopic rod of the solenoid valve; when the solenoid valve is powered off, the cross bar is connected to the telescopic rod; when the solenoid valve is powered on, the cross bar is disconnected from the telescopic rod.

11. The material impact testing method according to claim 10, wherein: During the impact test in step S2, first, the first electromagnetically driven release member and the second electromagnetically driven release member are controlled to be in an energized state, the first electromagnetically driven release member and the second electromagnetically driven release member are attracted to each other, and the active rod moves along with the first electromagnetically driven release member until it is separated from the driven rod, and the active rod is located below the driven rod; Secondly, the drive motor of the turntable is controlled to rotate, thereby driving the turntable to rotate, and then driving the connecting rod to drive the solenoid valve to move up and down repeatedly: When the hammer drop rod is about to rise, the solenoid valve is controlled to be in a power-off state, the telescopic rod is extended to a state combined with the cross bar, and the cross bar and the hammer drop rod are lifted and moved upward by the telescopic rod. When the hammer drop rod rises to a certain height, the solenoid valve is controlled to be in a power-on state, the telescopic rod is retracted and disconnected from the hammer drop rod. Under the action of gravity, the hammer drop rod causes a hammer to fall and hammer the test material. This operation is repeated to achieve repeated impacts on the material to be tested.

Images