An electromagnetically driven Hopkinson bar multiaxial tension-compression composite system

Abstract

The invention discloses an electromagnetically driven Hopkinson bar multi-axial tension-compression composite system, which relates to the technical field of dynamic mechanical property testing of materials. The system comprises N optical splitters, M photoelectric signal processors, and M electromagnetically driven Hopkinson bar uniaxial tension-compression systems. In the uniaxial tension-compression system, a tensile baffle is provided at the head end of an incident bar, a compression baffle is provided at the middle part, and the tail end is connected to a sample to be tested. An impact armature is sleeved on the incident bar. A coil accelerator is sleeved on the impact armature and connected to the photoelectric signal processor. Each optical splitter divides an initial control signal output by a host computer into M synchronous control signals and sends them to each photoelectric signal processor. Each photoelectric signal processor generates a working signal according to a control instruction and the N synchronous control signals. Each coil accelerator drives the impact armature to impact the tensile baffle or the compression baffle according to the working signal. The invention realizes tensile drive, compression drive, and a control combination test of tensile and compression drive on the sample to be tested.

Description

Technical Field

[0001] The present invention relates to the technical field of material dynamic mechanical property testing, in particular to an electromagnetically driven Hopkinson bar multi-axial tension-compression composite system. Background Art

[0002] In engineering applications, materials exhibit significant differences in mechanical properties under quasi-static and high-speed impact conditions. Materials also often exhibit different mechanical behaviors at different strain rates. Accurately and effectively testing the dynamic mechanical properties of materials at high strain rates is essential to meet the design and optimization requirements of material properties. Furthermore, many mechanical property tests, such as fracture strain and its corresponding stress triaxiality, require multiaxial tension or compression testing, making precise control of multiaxial synchronization and accuracy extremely important.

[0003] Currently, the split-Hopkinson bar technique is widely used to test the dynamic mechanical properties of materials. However, this technique generally uses compressed gas to accelerate a short bar, which then impacts the incident bar to generate the incident wave. The shortcomings of this method include an inaccurate relationship between the bar speed and gas pressure, low bar speed accuracy, the inability to precisely control the specimen strain rate, and difficulty adjusting the bar speed as needed.

[0004] For traditional loading systems, the shapes of the impact rods of the Hopkinson tension rod and compression rod and the positions of the gas compression devices are different, so traditional devices cannot meet the two working requirements of tension and compression on the same device.

[0005] In actual operation, the multi-axis Hopkinson bar stress wave generators currently available in public documents have different structural orientations for the compression and tension heads. The compression drive head is used when compression loading is required, and the tension drive head needs to be replaced when tension loading is required. This increases the complexity of experimental operations and prevents simultaneous tension and compression drive on different axes, preventing flexible combination based on actual needs. Furthermore, the outer circumferential surfaces of the tension and compression heads require clearance fit within the inner surface of the loading coil base. Once the dimensions of the loading coil housing are determined, the dimensions of the incident rod system cannot be changed, preventing the diameter of the rod system from being flexibly adjusted based on actual needs. Summary of the Invention

[0006] The purpose of the present invention is to provide an electromagnetically driven Hopkinson bar multi-axial tension-compression composite system, which can realize tension drive test, compression drive test and controlled combination test of tension drive and compression drive on a sample to be tested.

[0007] To achieve the above object, the present invention provides the following solutions:

[0008] An electromagnetically driven Hopkinson bar multiaxial tension-compression composite system, wherein the electromagnetically driven Hopkinson bar multiaxial tension-compression composite system is connected to a host computer and a sample to be tested, respectively; the host computer is used to output N initial control signals and M control instructions; the electromagnetically driven Hopkinson bar multiaxial tension-compression composite system includes N optical splitters, M photoelectric signal processors, and M electromagnetically driven Hopkinson bar uniaxial tension-compression systems; each optical splitter is connected to the host computer; each photoelectric signal processor is connected to the host computer;

[0009] Each electromagnetically driven Hopkinson bar uniaxial tension and compression system includes a coil accelerator, an impact armature, an incident rod, a compression baffle and a tension baffle:

[0010] The tensile baffle is fixedly provided at the head end of the incident rod, the compression baffle is fixedly provided at the middle part of the incident rod, and the tail end of the incident rod is connected to the sample to be tested; the impact armature is sleeved on the incident rod and is located between the tensile baffle and the compression baffle; the coil accelerator is sleeved on the impact armature and is connected to the photoelectric signal processor;

[0011] Each optical splitter is connected to each optoelectronic signal processor; each optical splitter divides one initial control signal into M synchronous control signals and sends them to each optoelectronic signal processor respectively;

[0012] Each photoelectric signal processor obtains a control instruction; the photoelectric signal processor is used to generate a working signal according to the N synchronous control signals and the control instruction and send it to the coil accelerator;

[0013] Each coil accelerator drives the impact armature to impact the tensile baffle or the compressive baffle according to the working signal, so as to stretch or compress the sample to be tested.

[0014] Optionally, the electromagnetically driven Hopkinson bar uniaxial tension and compression system further comprises: an incident strain gauge, a transmission rod and a transmission strain gauge;

[0015] Each of the incident strain gauges is connected to the host computer. The incident strain gauge is located at a position intermediate between the middle of the incident rod and the tail end of the incident rod. The incident strain gauge is used to collect incident and reflected stress waves. The head end of the transmission rod is connected to the sample to be tested. The transmission strain gauge is located in the middle of the transmission rod. The transmission strain gauge is used to collect transmitted stress waves. The host computer is used to obtain a compressive stress-strain curve or a tensile stress-strain curve of the sample to be tested based on the incident stress wave, the reflected stress wave, and the transmitted stress wave.

[0016] Optionally, the electromagnetically driven Hopkinson bar uniaxial tension and compression system further comprises: an incident strain gauge, a transmission rod and a transmission strain gauge;

[0017] Each of the incident strain gauges is connected to the host computer. The incident strain gauge is located at a position intermediate between the middle of the incident rod and the tail end of the incident rod. The incident strain gauge is used to collect incident and reflected stress waves. The head end of the transmission rod is connected to the sample to be tested. The transmission strain gauge is located in the middle of the transmission rod. The transmission strain gauge is used to collect transmitted stress waves. The host computer is used to obtain a compressive stress-strain curve or a tensile stress-strain curve of the sample to be tested based on the incident stress wave, the reflected stress wave, and the transmitted stress wave.

[0018] Optionally, the electromagnetically driven Hopkinson bar uniaxial tension and compression system further comprises: an electromagnetic protection sleeve;

[0019] The electromagnetic protection sleeve is sleeved between the incident rod and the impact armature, and is used to reduce the interference of the pulse electromagnetic force generated by the coil accelerator on the incident stress wave, the reflected stress wave and the transmitted stress wave.

[0020] Optionally, the electromagnetically driven Hopkinson bar uniaxial tension and compression system further comprises: a surface limiting structure;

[0021] The surface limiting structures are respectively connected to the electromagnetic protection sleeve and the incident rod, and each surface limiting structure is used to fix each electromagnetic protection sleeve.

[0022] Optionally, the electromagnetically driven Hopkinson bar uniaxial tension and compression system further comprises: a buffer;

[0023] The buffer is connected to the tail end of the transmission rod, and each buffer is used to prevent damage caused by each impact armature impacting each stretching baffle.

[0024] Optionally, the electromagnetically driven Hopkinson bar uniaxial tension and compression system further comprises: an initial limiting structure and an electromagnetic coil reinforcement shell;

[0025] The electromagnetic coil reinforcement shell is mounted on the electromagnetic coil accelerator, and the initial limiting structure is respectively connected to the magnetic coil reinforcement shell, the impact armature and the host computer. The initial limiting structure is used to fix the impact armature and is also used to release the fixation of the impact armature according to the control signal.

[0026] Optionally, each of the coil accelerators comprises:

[0027] A control trigger module, connected to the photoelectric signal processor, for receiving the working signal;

[0028] The electromagnetic coil winding is connected to the control trigger module. The electromagnetic coil winding drives the corresponding impact armature to impact the stretching baffle or the compression baffle according to the working signal, so as to stretch or compress the sample to be tested.

[0029] Optionally, the electromagnetically driven Hopkinson bar multi-axial tension-compression composite system further comprises: a plurality of power modules;

[0030] Each of the power modules is connected to a corresponding electromagnetic coil winding and is used to supply power to the corresponding electromagnetic coil winding.

[0031] Optionally, the power supply module is an adjustable power supply, and the current of the electromagnetic coil winding is changed by adjusting the output current of the adjustable power supply, thereby adjusting the impact speed of the impact armature.

[0032] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0033] In an embodiment of the present invention, N initial control signals are output by a host computer, and each optical splitter divides one initial control signal into M synchronous control signals, and sends them to each optoelectronic signal processor respectively; each optoelectronic signal processor generates a working signal according to the acquired control instruction and the N synchronous control signals, and sends it to the coil accelerator of the electromagnetically driven Hopkinson bar uniaxial tension and compression system; each coil accelerator drives the impact armature to impact the tensile baffle or the compression baffle according to the working signal, so as to stretch or compress the sample to be tested, thereby realizing the tensile drive test, compression drive test and control combination test of the tensile drive and compression drive of the sample to be tested. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0035] Figure 1 This is a schematic structural diagram of a first embodiment of the electromagnetically driven Hopkinson bar multi-axial tension-compression composite system of the present invention;

[0036] Figure 2 This is a schematic structural diagram of a second embodiment of the electromagnetically driven Hopkinson bar multi-axial tension-compression composite system of the present invention;

[0037] Figure 3 This is a control flow chart of an embodiment of the electromagnetically driven Hopkinson bar multi-axial tension-compression composite system of the present invention;

[0038] Figure 4 A schematic diagram of a circuit in which electromagnetic coil windings are connected in phase groups according to the present invention;

[0039] Figure 5This is a circuit diagram of the electromagnetic coil windings of the present invention connected in a single coil sequential discharge mode;

[0040] Figure 6 This is a circuit connection diagram of a three-axis accelerator using a single power module as an example of the present invention;

[0041] Figure 7 This is a front view of a three-axis embodiment of the present invention;

[0042] Figure 8 is a signal processing logic flow chart of the optoelectronic signal processor of the present invention;

[0043] Figure 9 Schematic diagram of the trigger control signal flow path of the multi-axis electromagnetic coil accelerator of the present invention.

[0044] Explanation of symbols:

[0045] Tensile baffle 1, coil accelerator 2, incident rod 3, incident strain gauge 31, test sample 4, compression baffle 5, transmission rod 6, transmission strain gauge 61, buffer 7, impact armature 8, initial limit structure 9, electromagnetic coil reinforcement shell 10, high-voltage switch 11, first coil winding 12, second coil winding 13, third coil winding 14, fourth coil winding 15, fifth coil winding 16, sixth coil winding 17. DETAILED DESCRIPTION

[0046] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0047] The purpose of the present invention is to provide an electromagnetically driven Hopkinson bar multi-axial tension-compression composite system, which realizes the tension drive test, compression drive test and controlled combination test of the tension drive and compression drive on the sample to be tested.

[0048] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0049] like Figure 1As shown, the electromagnetically driven Hopkinson rod multi-axial tension-compression composite system is connected to a host computer and a sample to be tested 4, respectively; the host computer is used to output N initial control signals and M control instructions; the electromagnetically driven Hopkinson rod multi-axial tension-compression composite system includes N spectrometers, M photoelectric signal processors and M electromagnetically driven Hopkinson rod uniaxial tension-compression systems; each spectrometer is connected to the host computer; each photoelectric signal processor is connected to the host computer.

[0050] Each electromagnetically driven Hopkinson bar uniaxial tension-compression system includes a coil accelerator 2 , an impact armature 8 , an incident rod 3 , a compression baffle 5 and a tension baffle 1 .

[0051] The tensile baffle 1 is fixedly provided at the head end of the incident rod 3, the compression baffle 5 is fixedly provided at the middle part of the incident rod 3, and the tail end of the incident rod 3 is connected to the sample to be tested 4; the impact armature 8 is sleeved on the incident rod 3 and is located between the tensile baffle 1 and the compression baffle 5; the coil accelerator 2 is sleeved on the impact armature 8; and the coil accelerator 2 is connected to the photoelectric signal processor.

[0052] Each optical splitter is connected to each optoelectronic signal processor; each optical splitter splits one initial control signal into M synchronous control signals and sends them to each optoelectronic signal processor respectively.

[0053] Each optoelectronic signal processor obtains a control instruction; the optoelectronic signal processor is used to generate a working signal according to N synchronous control signals and the control instruction and send the signal to the coil accelerator 2 .

[0054] Each coil accelerator 2 drives the impact armature 8 to impact the tensile baffle or the compression baffle 5 according to the working signal, so as to stretch or compress the sample 4 to be tested.

[0055] The tension baffle 1 and the compression baffle 5 are both disc-shaped baffles, and the diameter of the disc-shaped baffles is larger than the diameter of the impact armature 8. In order to ensure sufficient displacement of the impact armature 8 for acceleration, the distance between the disc-shaped baffle and the coil accelerator 2 is greater than the length of the impact armature 8.

[0056] At the same time, the photoelectric signal processor selects different working modes and determines different conversion processing logics (such as Figure 8 shown).

[0057] When the information carried by the control instruction is the same as the information carried by N synchronous control signals, the optoelectronic signal processor directly outputs the N synchronous control signals (i.e., working signals); when the information carried by the control instruction is different from the information carried by the N synchronous control signals, the optoelectronic signal processor inversely processes the N synchronous control signals to obtain an inverse signal (i.e., working signal) for output; the working signal is either one of the N synchronous control signals or the inverse signal; that is, the two working signals correspond to two working modes.

[0058] Taking a specific embodiment as an example, when the information carried by the control instruction is the same as the information carried by N synchronous control signals, the optoelectronic signal processor directly outputs the N synchronous control signals (i.e., working signals), and the working mode is compression at this time; when the information carried by the control instruction is different from the information carried by the N synchronous control signals, the optoelectronic signal processor reversely processes the N synchronous control signals and obtains an inverse signal (i.e., working signal) for output, and the working mode is stretching at this time.

[0059] In addition, the outer diameter and mass of the impact armature 8 are adjustable within the caliber range of the coil accelerator 2 , and the diameters of the incident rod 3 and the transmission rod 6 are adjustable within the inner diameter range of the impact armature 8 .

[0060] Fiber optic connections are used for fast transmission of high-precision signals.

[0061] Optionally, each of the coil accelerators includes a control trigger module and an electromagnetic coil winding.

[0062] The control trigger module is connected to the photoelectric signal processor and is used to receive the working signal.

[0063] The electromagnetic coil winding is connected to the control trigger module. Based on the working signal, the electromagnetic coil winding drives a corresponding impact armature to impact the stretching baffle or the compression baffle, thereby stretching or compressing the sample to be tested. The number of electromagnetic coil windings is the same as the number of initial synchronization control signals.

[0064] Taking a specific embodiment as an example, Figure 9 As shown, the host computer outputs the first electromagnetic coil winding signal, the second electromagnetic coil winding signal...the nth electromagnetic coil winding signal (n is 6, but not limited to this number); the electromagnetic coil winding signal is the initial control signal; each optical splitter divides one initial control signal into three synchronous control signals (not limited to three), and sends them to each optoelectronic signal processor respectively; the optoelectronic signal processor is used to generate a working signal based on the N synchronous control signals and control instructions and send it to the first single axis, the second single axis, and the third single axis.

[0065] Preferably, the electromagnetically driven Hopkinson bar uniaxial tension and compression system further includes: an incident strain gauge 31 , a transmission rod 6 and a transmission strain gauge 61 .

[0066] Each of the incident strain gauges 31 is connected to the host computer, and the incident strain gauge 31 is located in the middle position between the middle of the incident rod 3 and the tail end of the incident rod 3. The incident strain gauge 31 is used to collect incident and reflected stress waves; the head end of the transmission rod 6 is connected to the sample to be tested 4, and the transmission strain gauge 61 is located in the middle of the transmission rod 6. The transmission strain gauge 61 is used to collect transmitted stress waves; the host computer is used to obtain the compressive stress-strain curve or the tensile stress-strain curve of the sample to be tested 4 according to the incident stress wave, reflected stress wave and transmitted stress wave.

[0067] Preferably, the electromagnetically driven Hopkinson bar uniaxial tension and compression system further includes an electromagnetic protection sleeve.

[0068] The electromagnetic protection sleeve is sleeved between the incident rod 3 and the impact armature 8, and is used to reduce the interference of the pulse electromagnetic force generated by the coil accelerator 2 on the incident stress wave, reflected stress wave and transmitted stress wave.

[0069] The electromagnetic protection component is made of high magnetic permeability and low density material, and is woven into a mesh in a spiral 45-degree cross pattern. It is wrapped around the surface of the incident rod 3 inside the accelerator and fixed by a limiting structure on the surface of the incident rod 3.

[0070] Optionally, the electromagnetically driven Hopkinson bar uniaxial tension and compression system further includes: a surface limiting structure.

[0071] The surface limiting structures are respectively connected to the electromagnetic protection sleeve and the incident rod 3 , and each surface limiting structure is used to fix each electromagnetic protection sleeve.

[0072] In order to prevent the impact armatures 8 from impacting the stretching baffles 1 and causing damage, the electromagnetically driven Hopkinson bar uniaxial tension and compression system further includes a buffer 7 . The buffer 7 is connected to the tail end of the transmission rod 6 .

[0073] like Figure 2 As shown, the electromagnetically driven Hopkinson bar uniaxial tension and compression system further includes: an initial limiting structure 9 and an electromagnetic coil reinforcement shell 10.

[0074] The electromagnetic coil reinforcement shell 10 is mounted on the electromagnetic coil accelerator 2, and the initial limiting structure 9 is respectively connected to the electromagnetic coil reinforcement shell 10, the impact armature 8 and the host computer. The initial limiting structure 9 is used to fix the impact armature 8 and is also used to release the fixation of the impact armature 8 according to the control signal.

[0075] The initial limiting structure 9 can keep the impact armature 8 fixed in the vertical direction and prevent it from falling. When the excitation is triggered, the initial limiting structure 9 is released synchronously, allowing the impact armature 8 to accelerate.

[0076] The initial limit structure 9 and the electromagnetic coil receive the first trigger signal simultaneously, ensuring that the impact armature 8 is released at the same time as it begins to accelerate. The trigger timing of the three-axis electromagnetic coil accelerator 2 can be adjusted by the control terminal to compensate for the speed deviation of the three-axis impact armature 8 caused by gravity.

[0077] like Figure 7 As shown, a triaxial composite system is used as an example. The intersection ends of the incident rods 3 of the three electromagnetically driven Hopkinson bar uniaxial tension and compression systems are all connected to the sample 4 to be tested.

[0078] Optionally, the electromagnetically driven Hopkinson bar multi-axial tension-compression system further comprises: a plurality of power modules, each of which is connected to a corresponding electromagnetic coil winding and is used to supply power to the corresponding electromagnetic coil accelerator 2 .

[0079] like Figure 5 As shown, when the single coil discharge connection method is adopted, that is, discrete connection synchronous triggering, the direction of armature movement is changed by changing the triggering sequence of the pulse power supply connected to each coil.

[0080] like Figure 3 As shown, the host computer controls the coil windings at each level and synchronously controls the initial limiting structure 9.

[0081] like Figure 6 As shown, when the phase group connection method is adopted, that is, asynchronous triggering, the circuit topology of the electromagnetic coil winding and the power module can be a series, parallel or series-parallel mixed structure; the direction of armature movement is changed by changing the phase sequence.

[0082] like Figure 5As shown, the electromagnetic coil windings are based on the first coil winding 12, the second coil winding 13, ..., and the sixth coil winding 17. The first coil winding 12 is the first electromagnetic coil winding near the tension baffle 1. Similarly, the sixth coil winding 17 is the first electromagnetic coil winding near the compression baffle 5. Taking a three-phase system as an example, the windings are arranged axially in the phase sequence of A1, B1, C1, A2, B2, and C2. When the compression mode is required, the triggering sequence is A-B-C; when the tension mode is required, the triggering sequence is C-B-A. When using a three-phase drive system, the three-phase current flow path is "positive power supply to A1+ to A1- to A2+ to A2- to negative power supply"; "positive power supply to B1+ to B1- to B2+ to B2- to negative power supply"; and "positive power supply to C1+ to C1- to C2+ to C2- to negative power supply."

[0083] Preferably, the power supply module is an adjustable power supply, and the current of the electromagnetic coil winding is changed by adjusting the output current of the adjustable power supply, thereby adjusting the impact speed of the impact armature 8. That is, the exit speed or exit kinetic energy of the impact armature 8 is changed by changing the current.

[0084] Optionally, the electromagnetically driven Hopkinson bar uniaxial tension-compression system further includes a primary energy storage lithium battery. The primary energy storage lithium battery is connected to each of the power modules and is used to supply power to each of the power modules.

[0085] Optionally, the electromagnetically driven Hopkinson bar uniaxial tension-compression system further includes a charger connected to the pulse capacitor in the power module, and configured to charge the pulse capacitor in the power module.

[0086] like Figure 4 and Figure 6As shown in the figure, using a specific embodiment as an example, when the electromagnetic coil windings are connected in groups by phase, i.e., asynchronous triggering, each electromagnetic coil accelerator 2 includes six electromagnetic coil windings, with the first coil winding 12, the second coil winding 13, ..., and the sixth coil winding 17 being the first electromagnetic coil winding near the tension baffle 1. The first coil winding 12 is the first electromagnetic coil winding near the compression baffle 5, and the sixth coil winding 17 is the first electromagnetic coil winding near the compression baffle 5. The six electromagnetic coil windings are arranged axially in the phase sequence of A1, B1, C1, A2, B2, and C2. When the compression mode is required, the triggering sequence is phase A, B, and C. The armature to be accelerated is placed in the electromagnetic coil accelerator 2 and secured using the initial stop structure 9. An incident rod 3 is placed along the axis of the electromagnetic coil accelerator 2 and the armature. The tension baffle 1 and the compression baffle 5 are placed at either end of the accelerator. The electromagnetic coil windings of the same phase are connected to a power module according to the series circuit topology described above. The power module is powered by a pulse capacitor, and the pulse capacitor is charged by a charger. The discharge sequence of the pulse capacitor is controlled by a high-voltage switch 11. Each phase coil circuit uses a high-voltage switch 11, and a total of three high-voltage switches 11 are used to control the circuit switch. After the pulse capacitor is fully charged and reaches the set voltage amplitude, the high-voltage switch 11 is triggered to discharge in the ABC phase sequence. Pulse excitation is applied to the six electromagnetic coil windings in sequence. The armature mass is set to 5.8kg. The power module contains a 600uF capacitor, and the voltage amplitude is set to 10kV. The power supply conditions and the mass of the impact armature 8 in the first single axis, second single axis, third single axis, and three-axis directions are the same. The calculation results show that the exit velocity of the projectile load is around 158m / s.

[0087] In addition, the impact speed of the impact armature is adjusted by combining the control of the electromagnetic coil winding discharge triggering time interval between adjacent coil windings in each electromagnetic coil accelerator by each power supply module.

[0088] The present invention can change the triggering timing or working sequence of the electromagnetic coil winding, change the direction of armature movement, hit the compression baffle 5 or the tension baffle 1, and use a set of fixing devices to meet both tensioning and compression working requirements. By adjusting the primary energy scale and parameters such as capacitance and voltage amplitude in the circuit, the outlet speed of the load delivery can be independently controlled. The load mass and load outlet speed are adjustable. According to actual needs, the incident rod 3 and the transmission rod 6 of different diameters can be replaced within the range of the electromagnetic coil accelerator 2 and the armature aperture size. Samples of different sizes can be measured and flexibly adjusted according to usage requirements.

[0089] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0090] The principles and implementation methods of the present invention are described herein using specific examples. Those skilled in the art will appreciate that variations in the specific implementation methods and scope of application are possible based on the concepts of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. An electromagnetically driven Hopkinson bar multi-axial tension-compression composite system, characterized in that: The electromagnetically driven Hopkinson rod multi-axial tension-compression composite system is connected to a host computer and a sample to be tested, respectively; the host computer is used to output N initial control signals and M control instructions; the electromagnetically driven Hopkinson rod multi-axial tension-compression composite system includes N optical splitters, M photoelectric signal processors, and M electromagnetically driven Hopkinson rod uniaxial tension-compression systems; each optical splitter is connected to the host computer; each photoelectric signal processor is connected to the host computer; Each electromagnetically driven Hopkinson bar uniaxial tension and compression system includes a coil accelerator, an impact armature, an incident rod, a compression baffle and a tension baffle: The tensile baffle is fixedly provided at the head end of the incident rod, the compression baffle is fixedly provided at the middle part of the incident rod, and the tail end of the incident rod is connected to the sample to be tested; the impact armature is sleeved on the incident rod and is located between the tensile baffle and the compression baffle; the coil accelerator is sleeved on the impact armature and is connected to the photoelectric signal processor; Each optical splitter is connected to each optoelectronic signal processor; each optical splitter divides one initial control signal into M synchronous control signals and sends them to each optoelectronic signal processor respectively; Each photoelectric signal processor obtains a control instruction; the photoelectric signal processor is used to generate a working signal according to the N synchronous control signals and the control instruction and send it to the coil accelerator; Each coil accelerator drives the impact armature to impact the tensile baffle or the compressive baffle according to the working signal, so as to stretch or compress the sample to be tested.

2. The electromagnetic driven Hopkinson bar multi-axial tension-compression composite system according to claim 1, characterized in that: The electromagnetically driven Hopkinson bar uniaxial tension and compression system further comprises: an incident strain gauge, a transmission rod and a transmission strain gauge; Each of the incident strain gauges is connected to the host computer. The incident strain gauge is located at a position intermediate between the middle of the incident rod and the tail end of the incident rod. The incident strain gauge is used to collect incident and reflected stress waves. The head end of the transmission rod is connected to the sample to be tested. The transmission strain gauge is located in the middle of the transmission rod. The transmission strain gauge is used to collect transmitted stress waves. The host computer is used to obtain a compressive stress-strain curve or a tensile stress-strain curve of the sample to be tested based on the incident stress wave, the reflected stress wave, and the transmitted stress wave.

3. The electromagnetic driven Hopkinson bar multi-axial tension-compression composite system according to claim 2, characterized in that: The electromagnetic driven Hopkinson rod uniaxial tension and compression system further includes: an electromagnetic protection sleeve; The electromagnetic protection sleeve is sleeved between the incident rod and the impact armature, and is used to reduce the interference of the pulse electromagnetic force generated by the coil accelerator on the incident stress wave, the reflected stress wave and the transmitted stress wave.

4. The electromagnetic driven Hopkinson bar multi-axial tension-compression composite system according to claim 3, characterized in that: The electromagnetically driven Hopkinson bar uniaxial tension and compression system further includes: a surface limiting structure; The surface limiting structures are respectively connected to the electromagnetic protection sleeve and the incident rod, and each surface limiting structure is used to fix each electromagnetic protection sleeve.

5. The electromagnetic driven Hopkinson bar multi-axial tension-compression composite system according to claim 2, characterized in that: The electromagnetically driven Hopkinson bar uniaxial tension and compression system further includes: a buffer; The buffer is connected to the tail end of the transmission rod, and each buffer is used to prevent damage caused by each impact armature impacting each stretching baffle.

6. The electromagnetic driven Hopkinson bar multi-axial tension-compression composite system according to claim 1, characterized in that: The electromagnetic driven Hopkinson bar uniaxial tension and compression system further comprises: an initial limiting structure and an electromagnetic coil reinforcement shell; The electromagnetic coil reinforcement shell is mounted on the electromagnetic coil accelerator, and the initial limiting structure is respectively connected to the magnetic coil reinforcement shell, the impact armature and the host computer. The initial limiting structure is used to fix the impact armature and is also used to release the fixation of the impact armature according to the control signal.

7. The electromagnetic driven Hopkinson bar multi-axial tension-compression composite system according to claim 1, characterized in that: Each of the coil accelerators comprises: A control trigger module, connected to the photoelectric signal processor, for receiving the working signal; The electromagnetic coil winding is connected to the control trigger module. The electromagnetic coil winding drives the corresponding impact armature to impact the stretching baffle or the compression baffle according to the working signal, so as to stretch or compress the sample to be tested.

8. The electromagnetic driven Hopkinson bar multi-axial tension-compression composite system according to claim 7, characterized in that: The electromagnetically driven Hopkinson bar multi-axial tension-compression composite system further includes: a plurality of power modules; Each of the power modules is connected to a corresponding electromagnetic coil winding and is used to supply power to the corresponding electromagnetic coil winding.

9. The electromagnetic driven Hopkinson bar multi-axial tension-compression composite system according to claim 8, characterized in that: The power supply module is an adjustable power supply. By adjusting the output current of the adjustable power supply, the current of the electromagnetic coil winding is changed, and the impact speed of the impact armature is adjusted.

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