Multi-parallel-coil electromagnetic hopkinson bar and cooperative control method

Abstract

The application discloses a multi-parallel-coil electromagnetic Hopkinson bar and a cooperative control method. The multi-parallel-coil electromagnetic Hopkinson bar comprises a controller, a plurality of capacitors and a main coil. The controller is used for controlling discharge times of the plurality of capacitors. The plurality of capacitors are used for discharging respectively according to the discharge times. The main coil is used for generating corresponding target Lorentz forces in response to the discharges of the capacitors, so as to exert impact loads on a test piece by using the target Lorentz forces and complete dynamic mechanical property testing of the test piece. The main coil comprises a plurality of sub-coils arranged in a symmetrical annular array. Each sub-coil is an annular spiral structure, and any two adjacent sub-coils are different sub-coils. Each capacitor is connected with a corresponding sub-coil.

Description

Technical Field

[0001] This application relates to the technical field of structural mechanics experimental equipment, specifically to a multi-parallel coil electromagnetic Hopkinson rod and a collaborative control method. Background Technology

[0002] In the field of dynamic mechanical property testing of materials, the electromagnetic Hopkinson bar is a core device for achieving high strain rate loading and obtaining the mechanical response of materials in extreme environments. Its performance directly depends on the uniformity of magnetic field generation, the controllability of the Lorentz force, and the accuracy of discharge coordination. The core function of the electromagnetic Hopkinson bar relies on the transient Lorentz force generated by the pulse discharge of the main coil to drive the specimen, and its performance directly determines the stress wave morphology, loading intensity, and experimental repeatability.

[0003] However, in current related technologies, some electromagnetic Hopkinson bars using a single-coil design are structurally limited, resulting in a large magnetic field distribution gradient and a narrow effective area, leading to a limited peak Lorentz force and uneven load distribution on the test piece, making it impossible to achieve high-intensity, uniform impact loading. Other electromagnetic Hopkinson bars using multi-coil structures suffer from problems such as irregular coil arrangement leading to disordered magnetic field superposition, or continuous winding structures exacerbating electromagnetic interference. For example, patent CN114965013A proposes a trapezoidal stress wave generator with "radial multiple sets of series arrangement + parallel circuit," but it still has limitations. Key drawbacks include: the main coil is arranged in a radially layered configuration (divided into 4 groups of coils from the inside out), effectively expanding the working area to only 1.8 times that of traditional structures; the Lorentz force enhancement is limited (only 3.2 times compared to a single coil); the stability of the trapezoidal stress wave plateau segment is poor (pulse width fluctuation of ±15% in the plateau segment), and electromagnetic interference between sub-coils leads to waveform distortion ≥8%; patent CN114965013A uses a radially layered configuration (divided into 4 groups of coils from the inside out) to generate a trapezoidal stress wave, increasing the peak current to 120KA, but its disadvantages include uneven magnetic field, limited Lorentz force enhancement, and large plateau segment fluctuations. Therefore, optimizing the structure of the electromagnetic Hopkinson bar to improve magnetic field uniformity and the controllability of the Lorentz force is crucial to enhancing the reliability and stability of dynamic mechanical testing of materials. Summary of the Invention

[0004] This application provides a multi-parallel coil electromagnetic Hopkinson bar and a collaborative control method, which optimizes the structure of the electromagnetic Hopkinson bar, improves the uniformity of the magnetic field and the controllability of the Lorentz force, thereby improving the performance of dynamic mechanical testing of materials.

[0005] To achieve the above objectives, this application provides the following technical solution:

[0006] In a first aspect, embodiments of this application provide a multi-parallel coil electromagnetic Hopkinson bar, comprising:

[0007] A controller used to control the discharge time of multiple capacitors;

[0008] Multiple capacitors, each used to discharge according to its designated discharge time;

[0009] The main coil is used to generate a target Lorentz force in response to the discharge of the capacitor, so as to apply an impact load to the test piece and complete the dynamic mechanical performance test of the test piece. The main coil includes multiple sub-coils arranged in a symmetrical ring array. Each sub-coil is a ring spiral structure, and any two adjacent sub-coils are different sub-coils. Each capacitor is connected to the corresponding sub-coil.

[0010] In some embodiments of this application, it also includes:

[0011] A composite insulation layer is used to achieve insulation isolation between adjacent different sub-coils;

[0012] The composite insulation layer is disposed between adjacent sub-coils; the spacing between adjacent sub-coils is a preset spacing value.

[0013] In some embodiments of this application, it also includes:

[0014] Anti-instability component, used to suppress deformation of sub-coil under Lorentz force;

[0015] An anti-instability component is disposed on the surface of the sub-coil; the anti-instability component includes a glass fiber cloth reinforcement layer with a preset thickness and preset tensile strength.

[0016] In some embodiments of this application, each sub-coil is provided with positive and negative electrodes to achieve electrical connection between the sub-coil and the capacitor;

[0017] The positive terminal of the sub-coil is connected to the positive terminal of the capacitor, and the negative terminal of the sub-coil is connected to the negative terminal of the capacitor.

[0018] In some embodiments of this application, the capacitor is a direct discharge capacitor or an indirect energy storage and release capacitor;

[0019] Direct discharge capacitors are used for direct output of pulse current;

[0020] The indirect energy storage and release type capacitor is connected in series with an inductor compensation module, which is used to optimize the pulse current waveform.

[0021] In some embodiments of this application, multiple sub-coils arranged in a symmetrical ring array in the main coil are located on the same plane; or, the multiple sub-coils are not located on the same plane.

[0022] In some embodiments of this application, the number of turns of each sub-coil is equal to the ratio of the total number of turns of the main coil to the number of sub-coils.

[0023] Secondly, embodiments of this application provide a cooperative control method applied to a multi-parallel coil electromagnetic Hopkinson rod. The multi-parallel coil electromagnetic Hopkinson rod includes a controller, multiple capacitors, and a main coil. The main coil includes multiple sub-coils arranged in a symmetrical ring array. Each sub-coil has a ring-shaped spiral structure, and any two adjacent sub-coils are different sub-coils. The multiple capacitors are respectively connected to the multiple sub-coils. The method includes:

[0024] The controller sends discharge control signals to multiple capacitors, causing the multiple capacitors to discharge in response to the discharge control signals;

[0025] By responding to the discharge of multiple capacitors in the main coil, a corresponding target Lorentz force is generated, and the target Lorentz force is used to apply an impact load to the test piece to complete the dynamic mechanical property test of the test piece.

[0026] In some embodiments of this application, a target Lorentz force is generated by the main coil responding to the discharge of multiple capacitors, including:

[0027] When the discharge control signal is a synchronous discharge control signal, the target Lorentz force is generated by the synchronous discharge of multiple capacitors in response to the main coil, based on the total current formed by the superposition of the currents of each sub-coil.

[0028] In some embodiments of this application, a target Lorentz force is generated by the main coil responding to the discharge of multiple capacitors, including:

[0029] When the discharge control signal is a time-sharing discharge control signal, the main coil responds to the time-sharing discharge of multiple capacitors according to a preset delay time, and the Lorentz force generated by each sub-coil is superimposed based on the preset delay time to obtain the target Lorentz force. Attached Figure Description

[0030] To more intuitively illustrate the prior art and this application, several exemplary figures are provided below. It should be understood that the specific shapes and structures shown in the figures should not generally be regarded as limiting conditions for implementing this application; for example, based on the technical concept disclosed in this application and the exemplary figures, those skilled in the art are able to easily make conventional adjustments or further optimizations to the addition / reduction / classification, specific shapes, positional relationships, connection methods, size ratios, etc. of certain units (components).

[0031] Figure 1 A schematic diagram of the composition structure of the multi-parallel coil electromagnetic Hopkinson bar provided in the embodiments of this application. Figure 1 ;

[0032] Figure 2 A front view of the main coil provided in an embodiment of this application;

[0033] Figure 3 A schematic diagram illustrating the implementation process of the collaborative control method provided in the embodiments of this application;

[0034] Figure 4 A top view of the main coil provided in an embodiment of this application;

[0035] Figure 5 A schematic diagram of the composition structure of the multi-parallel coil electromagnetic Hopkinson bar provided in the embodiments of this application. Figure 2 .

[0036] Figure label:

[0037] Multi-parallel coil electromagnetic Hopkinson rod 0, controller 1, capacitor 2, main coil 3;

[0038] First positive terminal 211, second positive terminal 221, third positive terminal 231, fourth positive terminal 241, first negative terminal 212, second negative terminal 222, third negative terminal 232, fourth negative terminal 242; first sub-coil 31, second sub-coil 32, third sub-coil 33;

[0039] The first capacitor is 201, the second capacitor is 202, the third capacitor is 203, and the fourth capacitor is 204. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. Any combination of different embodiments is possible.

[0041] In the description of this application: unless otherwise stated, "a plurality of" means two or more. The terms "first," "second," "third," etc., in this application are intended to distinguish the objects referred to and do not have any special meaning in terms of technical connotation (e.g., they should not be construed as an emphasis on importance or order). Expressions such as "including," "comprising," and "having" also mean "not limited to" (certain units, components, materials, steps, etc.).

[0042] To address the problems encountered in current dynamic mechanical performance testing based on multi-parallel coil electromagnetic Hopkinson bars, such as uneven radial magnetic fields of multiple coils, limited Lorentz force enhancement, instability of the trapezoidal stress wave plateau segment, and low current density and monotonous waveform of a single coil, this application provides a multi-parallel coil electromagnetic Hopkinson bar and a collaborative control method, which can significantly enhance the Lorentz force, expand the effective magnetic field region, and precisely control the trapezoidal stress wave.

[0043] The cooperative control method embodiment of this application corresponds to the multi-parallel coil electromagnetic Hopkinson rod embodiment. The execution of the method embodiment depends on the hardware structure support of the device embodiment, so the relevant content will not be described in detail in the cooperative control method embodiment.

[0044] This application provides a multi-parallel coil electromagnetic Hopkinson bar, such as... Figure 1 As shown, the multi-parallel coil electromagnetic Hopkinson rod 0 includes a controller 1, multiple capacitors 2, and a main coil 3.

[0045] Controller 1 is used to control the discharge time of multiple capacitors 2.

[0046] In the embodiments of this application, controller 1 refers to a control unit with signal receiving, processing and command output functions, such as a field-programmable gate array (FPGA) controller 1.

[0047] Multiple capacitors 2 are used to discharge according to the discharge time.

[0048] The main coil 3 is used to generate a corresponding target Lorentz force in response to the discharge of capacitor 2, so as to apply an impact load to the test piece using the target Lorentz force and complete the dynamic mechanical performance test of the test piece; wherein, the main coil 3 includes multiple sub-coils arranged in a symmetrical ring array; each sub-coil is a ring spiral structure, and any two adjacent sub-coils are different sub-coils; each capacitor 2 is connected to the corresponding sub-coil.

[0049] In embodiments of this application, the number of capacitors 2 can be the same as the number of sub-coils.

[0050] In the embodiments of this application, the main coil 3 refers to the core electromagnetic component used to generate the magnetic field and Lorentz force.

[0051] In the embodiments of this application, the symmetrical ring array arrangement can be understood as multiple sub-coils being uniformly and symmetrically distributed with the ring as the reference; such as Figure 2 As shown, from the front view of the main coil 3, the four sub-coils are arranged in a symmetrical ring array. Each sub-coil is a ring spiral structure, and any two adjacent sub-coils are different sub-coils. For example, the two adjacent second sub-coils 32 and third sub-coils 33 of the first sub-coil 31 are different sub-coils; thus forming the main coil 3.

[0052] It is understandable that capacitor 2 is electrically connected to the sub-coil one-to-one, enabling independent power supply.

[0053] In the embodiments of this application, the combination of the aforementioned symmetrical ring array arrangement and ring spiral structure makes the magnetic fields generated by each sub-coil more evenly distributed after superposition, avoiding the defect of large magnetic field gradient in a single coil. The design of adjacent sub-coils being different sub-coils reduces electromagnetic interference of the same sub-coil and improves magnetic field utilization. The accurate generation of the target Lorentz force ensures the stability of the impact load and provides a structural basis for the accurate testing of the dynamic mechanical properties of the test piece. Compared with the traditional single-coil device, the peak value of the Lorentz force is significantly improved, the testing application range is wider, and it can also solve the problem of poor discharge coordination in current multi-coil devices.

[0054] In some embodiments of this application, the multiple sub-coils arranged in a symmetrical ring array in the main coil 3 are located on the same plane; or, the multiple sub-coils are not located on the same plane.

[0055] It is understandable that "located in the same plane" means that all sub-coils are arranged in a symmetrical ring array on the same horizontal plane; "not located in the same plane" means that the sub-coils are still arranged in a symmetrical ring array, but distributed on planes at different heights, forming a three-dimensional ring array.

[0056] In some embodiments of this application, the main coil 3 composed of multiple sub-coils arranged in the same plane is suitable for test scenarios with high requirements for magnetic field planarity, while the main coil 3 composed of multiple sub-coils not arranged in the same plane can be suitable for test scenarios that require three-dimensional magnetic field coverage.

[0057] In the embodiments of this application, the design of two arrangement methods enables the multi-parallel coil electromagnetic Hopkinson rod to have stronger scene adaptability. A planar arrangement ensures a uniform distribution of the magnetic field within the test plane, meeting the requirements of planar loading tests; a non-planar arrangement can form a three-dimensional magnetic field, expanding the effective area of ​​the magnetic field and adapting to irregularly shaped test pieces or those requiring omnidirectional loading. Compared to devices with a single arrangement method, this application breaks the limitations of test scenarios, expands the applicability of the multi-parallel coil electromagnetic Hopkinson rod, and maintains the magnetic field superposition advantage of a symmetrical ring array arrangement, ensuring that a stable target Lorentz force can be generated under different arrangement methods.

[0058] In some embodiments of this application, the number of turns of each sub-coil is equal to the ratio of the total number of turns of the main coil 3 to the number of sub-coils.

[0059] For example, where N is the total number of turns and M is the number of sub-coils, then the number of turns per sub-coil n = N / M; this setting ensures that the total number of turns of the main coil 3 is evenly distributed among each sub-coil, guaranteeing a consistent number of turns per sub-coil; for example... Figure 2As shown, four sub-coils (M=4) are used. The total number of turns of the main coil 3 is N=16 turns, and the number of turns of each sub-coil is n=16 / 4=4 turns. The sub-coils adopt a ring-shaped spiral structure and are arranged in a symmetrical ring array on the same plane.

[0060] In the embodiments of this application, by evenly distributing the number of turns, the problem of uneven magnetic field strength caused by inconsistent number of turns in sub-coils of multi-coil devices in current related technologies can be solved. With each sub-coil having the same number of turns, the magnetic field strength generated by each sub-coil under the same discharge conditions is consistent, resulting in more precise magnetic field superposition and stronger controllability of the target Lorentz force. Uniform turn distribution also reduces electromagnetic interference between sub-coils, avoids current imbalance caused by differences in the number of turns, and improves the stability of stress waves, thereby providing a reliable data basis for comparative analysis of the dynamic mechanical properties of materials.

[0061] In some embodiments of this application, the multi-parallel coil electromagnetic Hopkinson bar also includes a composite insulation layer for achieving insulation isolation between adjacent different sub-coils.

[0062] In the embodiments of this application, the composite insulating layer can be a layered structure made of insulating materials such as epoxy resin.

[0063] In the embodiments of this application, the composite insulation layer is disposed between adjacent sub-coils; the spacing between adjacent sub-coils is a preset spacing value.

[0064] In the embodiments of this application, the preset spacing value can be set according to insulation requirements, magnetic field distribution, and coil structure or size; for example, the preset spacing value can be 1.4 mm (including a 0.5 mm composite insulation layer).

[0065] For example, the composite insulation layer can be an epoxy resin composite structure with a thickness of 0.5 mm.

[0066] In the embodiments of this application, the composite insulation layer solves the core problems of electromagnetic interference and short circuits between adjacent coils in multi-coil arrangements, providing a safety guarantee for the independent discharge of each sub-coil. The preset spacing design makes the installation of the insulation layer more standardized, ensuring uniform spacing between adjacent sub-coils and further improving the uniformity of magnetic field distribution. Compared with devices without an insulation layer or with unreasonable insulation structure, this application can effectively reduce the distortion rate of stress waves, improve the reliability of test data, extend the service life of coils, and reduce equipment maintenance costs.

[0067] In embodiments of this application, the multi-parallel coil electromagnetic Hopkinson rod further includes an anti-instability component for suppressing the deformation of the sub-coils under the action of Lorentz force.

[0068] In the embodiments of this application, the anti-instability component refers to a component used to suppress the deformation of the sub-coil under the action of electromagnetic force.

[0069] In the embodiments of this application, the anti-instability component is disposed on the surface of the sub-coil; the anti-instability component includes a glass fiber cloth reinforcement layer with a preset thickness and a preset tensile strength.

[0070] In the embodiments of this application, the preset thickness and preset tensile strength can be set according to the stress condition of the sub-coil and the deformation control requirements.

[0071] In some embodiments of this application, the thickness of the fiberglass cloth reinforcement layer directly determines its structural load-bearing capacity and tensile strength reserve. Based on the stress conditions of the sub-coil, this application sets the preset thickness of the fiberglass cloth reinforcement layer to 0.2 mm to effectively suppress coil deformation, and the corresponding preset tensile strength is set to ≥800 MPa. The preset thickness of 0.2 mm is the optimal thickness for the surface bonding installation of the sub-coil. This thickness can ensure a tight fit between the fiberglass cloth reinforcement layer and the surface of the sub-coil, avoiding an increase in the overall volume of the coil and affecting the assembly accuracy due to excessive thickness. It can also provide a basic structural support base for the fiberglass cloth reinforcement layer, ensuring the effective performance of tensile strength. The preset tensile strength ≥800 MPa is a critical performance index set based on the magnitude of the electromagnetic Lorentz force generated when the sub-coil is working. This tensile strength value can completely resist the tensile stress brought by the electromagnetic force during the discharge of the sub-coil, preventing the reinforcement layer from breaking or failing due to stress, thereby constraining the deformation of the coil.

[0072] In the embodiments of this application, the glass fiber cloth reinforcement layer refers to a layered component woven from glass fiber as raw material, used to enhance structural stability.

[0073] In some embodiments of this application, the type of glass fiber cloth reinforcement layer can be alkali-free electronic-grade glass fiber cloth. Alkali-free electronic-grade glass fiber cloth is a layered fabric made from alkali-free glass fiber using a plain weave process. It is suitable for electromagnetic interference scenarios and has both insulation and structural reinforcement properties.

[0074] In some embodiments of this application, in a direction perpendicular to the plane of the main coil 3, the sub-coil has two opposing surfaces, and the anti-instability component can be attached to these two opposing surfaces respectively to form a double-layer reinforced structure.

[0075] For example, a 0.2mm thick (preset thickness) fiberglass cloth reinforcement layer is attached to the upper and lower surfaces of the sub-coil, with a tensile strength (preset tensile strength) ≥800MPa, and epoxy resin is injected and cured to suppress coil deformation caused by electromagnetic force, so that the cumulative deformation is ≤0.1mm.

[0076] In the embodiments of this application, the sub-coil is prone to deformation under the action of Lorentz force, leading to a shift in the magnetic field distribution and distortion of stress wave parameters. By setting an anti-instability component, the deformation of the sub-coil can be effectively suppressed, ensuring that the sub-coil always maintains the preset arrangement and structural parameters. The design of preset thickness and preset tensile strength makes the anti-instability component adapt to the stress requirements of the sub-coil, avoiding structural redundancy caused by over-strengthening or instability caused by insufficient strengthening. This effectively improves the structural stability and test repeatability of the multi-parallel coil electromagnetic Hopkinson bar. Compared with the test device without anti-instability design, the fluctuation amplitude of the stress wave plateau segment is significantly reduced, and the reliability of the test data is greatly improved.

[0077] In some embodiments of this application, each sub-coil is provided with positive and negative electrodes to realize the electrical connection between the sub-coil and the capacitor 2; wherein, the positive terminal of the sub-coil is connected to the positive terminal of the capacitor 2, and the negative terminal of the sub-coil is connected to the negative terminal of the capacitor 2.

[0078] In the embodiments of this application, positive and negative electrodes refer to conductive components disposed at both ends of the sub-coil to achieve electrical connection.

[0079] For example, such as Figure 2 As shown, each sub-coil has independent electrodes at both ends, including positive and negative electrodes; wherein, the first positive electrode 211 and the first negative electrode 212 are the positive and negative electrodes of a sub-coil, the second positive electrode 221 and the second negative electrode 222 are the positive and negative electrodes of a sub-coil, the third positive electrode 231 and the third negative electrode 232 are the positive and negative electrodes of a sub-coil, and the fourth positive electrode 241 and the fourth negative electrode 242 are the positive and negative electrodes of a sub-coil.

[0080] For example, for such Figure 2 Regarding the structure of the main coil 3 shown, capacitor 2 can be selected from two sets of direct discharge type capacitors (capacity 150μF, voltage 30kV) and two sets of indirect energy storage and release type capacitors (series inductor compensation module, inductance value 50nH).

[0081] In the embodiments of this application, the corresponding connection method of the positive and negative electrodes avoids problems such as current disturbance and energy loss caused by reverse connection, ensuring the energy transfer efficiency from capacitor 2 to the sub-coil. Stable electrical connection reduces energy loss and heat generation caused by contact resistance, lowers the device temperature rise, and extends the service life of capacitor 2 and the sub-coil. Compared to devices without clear electrode connection specifications, this application can make the current parameters of each sub-coil more stable and the magnetic field superposition effect more accurate, thereby improving the controllability of the target Lorentz force and providing electrical assurance for the accuracy of test results.

[0082] In some embodiments of this application, capacitor 2 is a direct discharge capacitor or an indirect energy storage and release capacitor; the direct discharge capacitor is used to directly output pulse current; the indirect energy storage and release capacitor is connected in series with an inductor compensation module, which is used to optimize the pulse current waveform.

[0083] In the embodiments of this application, a direct discharge capacitor refers to a capacitor that can directly output pulse current to the sub-coil without the need for additional energy storage and conversion.

[0084] In the embodiments of this application, an indirect energy storage and release type capacitor refers to a capacitor that needs to release pulse current after energy storage conversion.

[0085] In the embodiments of this application, the inductance compensation module can be used to adjust the current waveform and compensate for inductance loss.

[0086] In the embodiments of this application, the design of two capacitor types allows the device to adapt to different testing scenarios. The direct discharge capacitor can quickly output pulse current, meeting the requirements of high strain rate and short pulse loading; the indirect energy storage and release capacitor, in conjunction with the inductor compensation module, can optimize the rising and falling edges of the pulse current, avoiding magnetic field fluctuations caused by sudden current changes. The addition of the inductor compensation module solves the stress wave distortion problem caused by poor current waveforms in current related testing devices, making the stress wave shape more regular. The above design can effectively improve the versatility and testing flexibility of the device. Compared with devices with a single capacitor type, it can meet the needs of more materials and more testing conditions, expanding the application range of the device.

[0087] This application provides a multi-parallel coil electromagnetic Hopkinson bar, including a controller 1 for controlling the discharge time of multiple capacitors 2; multiple capacitors 2 are used to discharge according to the discharge time; a main coil 3 is used to generate a corresponding target Lorentz force in response to the discharge of capacitors 2, so as to apply an impact load to the test piece using the target Lorentz force to complete the dynamic mechanical performance test of the test piece; wherein, the main coil 3 includes multiple sub-coils arranged in a symmetrical ring array; each sub-coil is a ring spiral structure, and any two adjacent sub-coils are different sub-coils; each capacitor 2 is connected to the corresponding sub-coil. Therefore, it can be seen that this application, through the coordinated design and structured arrangement of controller 1, multiple capacitors 2, and main coil 3, can precisely solve the core defects of single-coil and disordered multi-coil structures in current related technologies, with significant technical effects: First, the main coil 3 adopts a symmetrical ring array arrangement and a ring spiral structure, and adjacent sub-coils are different sub-coils, which completely changes the problem of large magnetic field gradient and narrow effective area of ​​single coils. This makes the magnetic field generated by each sub-coil superimposed and distributed more evenly, significantly expanding the effective area. At the same time, it avoids the drawbacks of disordered multi-coil magnetic field superposition disorder and continuous winding aggravating electromagnetic interference, greatly reducing electromagnetic interference between sub-coils; Second, multiple capacitors 2 are connected one-to-one with multiple sub-coils, in conjunction with the controller. 1. Precise control of discharge time enables independent and coordinated discharge of each sub-coil. Compared with the limited peak value of Lorentz force in a single coil, the target peak value of Lorentz force is significantly improved through the superposition effect of current in multiple sub-coils. Moreover, the uniform magnetic field distribution ensures that the impact load is applied evenly to the test piece, solving the problem of uneven load distribution in a single coil. 2. The coordinated optimization of the overall structure simultaneously improves the uniformity of the magnetic field, the controllability of the Lorentz force, and the precision of discharge coordination, ensuring the stability and controllability of the impact load. This fundamentally improves the problems of poor data repeatability and low reliability in dynamic mechanical testing of materials, significantly enhancing the reliability and stability of the test, and making it suitable for testing scenarios with high loading accuracy requirements, such as aerospace composite materials and armor materials.

[0088] Based on the above embodiments, in another embodiment of this application, a cooperative control method is provided, applied to a multi-parallel coil electromagnetic Hopkinson rod 0; the multi-parallel coil electromagnetic Hopkinson rod 0 includes a controller 1, multiple capacitors 2, and a main coil 3; the main coil 3 includes multiple sub-coils arranged in a symmetrical ring array; each sub-coil has a ring spiral structure, and any two adjacent sub-coils are different sub-coils; the multiple capacitors 2 are respectively connected to the multiple sub-coils; as shown Figure 3 As shown, the cooperative control method may include the following steps:

[0089] Step 101: Send a discharge control signal to multiple capacitors 2 through controller 1 so that multiple capacitors 2 discharge in response to the discharge control signal.

[0090] In the embodiments of this application, the multi-parallel coil electromagnetic Hopkinson rod 0 can send a discharge control signal to multiple capacitors 2 through the controller 1, so that the multiple capacitors 2 discharge in response to the discharge control signal.

[0091] In the embodiments of this application, the discharge control signal refers to the electrical signal issued by the controller 1 to control the discharge time and discharge mode of the capacitor 2.

[0092] Step 102: The main coil 3 responds to the discharge of multiple capacitors 2 to generate a corresponding target Lorentz force, and the target Lorentz force is used to apply an impact load to the test piece to complete the dynamic mechanical performance test of the test piece.

[0093] In the embodiments of this application, the multi-parallel coil electromagnetic Hopkinson rod 0 can send a discharge control signal to multiple capacitors 2 through the controller 1 so that the multiple capacitors 2 discharge in response to the discharge control signal. Then, the main coil 3 responds to the discharge of the multiple capacitors 2 to generate a corresponding target Lorentz force, and uses the target Lorentz force to apply an impact load to the test piece to complete the dynamic mechanical performance test of the test piece.

[0094] In the embodiments of this application, the target Lorentz force refers to the Lorentz force that meets the test requirements generated after the main coil 3 responds to the discharge.

[0095] In the embodiments of this application, impact load refers to the dynamic load generated by the target Lorentz force acting on the test piece.

[0096] In the embodiments of this application, the discharge control signal sent by controller 1 ensures the consistency or difference in the discharge timing of multiple capacitors 2, providing a control basis for the accurate generation of the target Lorentz force. Compared with traditional testing methods that rely on mechanical impact, this application applies impact loads through electromagnetic drive, resulting in a contactless and wear-free loading process and better test repeatability. Furthermore, this method is based on the structure of a multi-parallel coil electromagnetic Hopkinson bar 0, which fully leverages the structural advantages of the symmetrical arrangement of multiple sub-coils in the multi-parallel coil electromagnetic Hopkinson bar 0, making the test results more reflective of the mechanical response of the test piece under real dynamic loads, and significantly improving test accuracy.

[0097] In some embodiments of this application, when the multi-parallel coil electromagnetic Hopkinson rod 0 generates the corresponding target Lorentz force by responding to the discharge of multiple capacitors 2 through the main coil 3, the target Lorentz force can be generated by responding to the synchronous discharge of multiple capacitors 2 through the main coil 3 when the discharge control signal is a synchronous discharge control signal, based on the total current formed by the superposition of the currents of each sub-coil.

[0098] In the embodiments of this application, the synchronous discharge control signal refers to the control signal used to control multiple capacitors 2 to start discharging simultaneously, so as to ensure that the discharge time difference of each capacitor 2 is within a preset synchronous range.

[0099] In the embodiments of this application, the total current formed by the superposition of currents refers to the total current formed by the sum of the currents generated by multiple sub-coils in the superposition region of the magnetic field, and its amplitude is the sum of the current amplitudes of each sub-coil.

[0100] In the embodiments of this application, the core advantage of the synchronous discharge mode is the maximization of the Lorentz force. The currents of each sub-coil are synchronously superimposed, significantly increasing the total current amplitude. According to the Lorentz force formula F=BIL, with a fixed magnetic field strength B and conductor length L, an increase in current I directly leads to an increase in the peak Lorentz force F. This mode solves the problem of insufficient peak Lorentz force in existing electromagnetic Hopkinson bars, meeting the testing requirements for high strength and high loads, and is suitable for impact resistance testing of armor materials, aerospace structural materials, etc. Simultaneously, synchronous discharge ensures the coordinated superposition of currents in each sub-coil, avoiding mutual cancellation during the current superposition process, improving energy utilization efficiency. Compared to the asynchronous discharge mode, the peak Lorentz force can be increased several times, further expanding the applicability of the test.

[0101] In some embodiments of this application, when the multi-parallel coil electromagnetic Hopkinson rod 0 generates a corresponding target Lorentz force by responding to the discharge of multiple capacitors 2 through the main coil 3, it can, under the condition that the discharge control signal is a time-sharing discharge control signal, respond to the time-sharing discharge of multiple capacitors 2 through the main coil 3 according to a preset delay time, so as to superimpose the Lorentz forces generated by each sub-coil based on the preset delay time to obtain the target Lorentz force.

[0102] In the embodiments of this application, the time-sharing discharge control signal refers to the control signal used to control multiple capacitors 2 to start discharging sequentially at preset time intervals.

[0103] In the embodiments of this application, the preset delay time is used to indicate the time difference between the start of discharge of adjacent capacitors 2. The preset delay time can be set according to specific test requirements, and this application does not limit it.

[0104] For example, the preset delay time is k, k > 10 ns, and the delay difference between adjacent sub-coils is 50~200 μs, so that the half-sine stress waves generated by each sub-coil are superimposed in an orderly manner to generate a perfect trapezoidal stress wave with a rising edge ≤ 50 μs, a plateau pulse width of 200~500 μs, and a falling edge ≤ 50 μs.

[0105] For example, using the above-mentioned synchronous discharge or time-division discharge test method, the test piece is repeatedly tested 10 times to obtain multiple sets of Lorentz force peak value and stress wave waveform data. When the data repeatability error is ≤2%, the final test result is output.

[0106] This application provides a collaborative control method applied to a multi-parallel coil electromagnetic Hopkinson rod 0. The multi-parallel coil electromagnetic Hopkinson rod 0 includes a controller 1, multiple capacitors 2, and a main coil 3. The main coil 3 includes multiple sub-coils arranged in a symmetrical ring array. Each sub-coil has a ring-shaped spiral structure, and any two adjacent sub-coils are different sub-coils. The multiple capacitors 2 are connected to the multiple sub-coils respectively. The controller 1 sends a discharge control signal to the multiple capacitors 2, causing the multiple capacitors 2 to discharge in response to the discharge control signal. The main coil 3 responds to the discharge of the multiple capacitors 2, generating a corresponding target Lorentz force, and uses the target Lorentz force to apply an impact load to the test piece to complete the dynamic mechanical performance test of the test piece. Therefore, this application, relying on the symmetrical ring array arrangement, ring-shaped spiral structure, and the design of adjacent different sub-coils in the main coil 3, uses the controller 1 to uniformly send a discharge control signal, enabling the multiple capacitors 2 and multiple sub-coils to respond accurately and discharge collaboratively, completely solving the problem of disordered magnetic field superposition and disturbance in multiple coils. The magnetic fields generated by each sub-coil are superimposed in an orderly manner in space, greatly improving the uniformity of the magnetic field distribution and significantly expanding the effective area. This avoids the defects of large magnetic field gradient and narrow effective area of ​​a single coil, while eliminating electromagnetic interference caused by continuous winding structure, laying the foundation for uniform load application. The control logic of one-to-one discharge of multiple capacitors 2 and multiple sub-coils enables the current of each sub-coil to be efficiently superimposed, solving the problem of limited peak value of Lorentz force of a single coil. At the same time, the uniform magnetic field distribution allows the impact load converted from Lorentz force to be applied evenly to the test piece, completely improving the drawback of uneven load distribution of a single coil and realizing high-intensity, uniform impact loading. The precise control of the discharge control signal by the controller 1 ensures the consistency and controllability of the discharge sequence of each capacitor 2, allowing the generation timing, amplitude and shape of Lorentz force to be precisely controlled, avoiding the problems of large load fluctuation and poor controllability in current related technologies. Through the above collaborative control methods, the repeatability of the testing process is greatly improved and the data reliability is significantly enhanced. This fundamentally solves the core pain point of insufficient reliability and stability in material dynamic mechanics testing, and is effectively adapted to scenarios with high requirements for loading accuracy and testing stability, such as aerospace composite materials and armor materials.

[0107] Based on the above embodiments, in another embodiment of this application, addressing the shortcomings of related technologies in the field of high-energy pulsed electromagnetic drive and material dynamic testing technology, such as uneven radial multi-coil magnetic fields, limited Lorentz force enhancement, unstable trapezoidal stress wave plateau segment, and low current density and single waveform of a single coil, this embodiment proposes an electromagnetic Hopkinson bar structure with a planar / non-planar multi-parallel coil topology. Through distributed capacitor control, a synergistic control method for enhancing Lorentz force and precisely regulating trapezoidal stress waves is achieved, which can realize significant enhancement of Lorentz force, expansion of effective magnetic field region, and precise regulation of trapezoidal stress waves. It is suitable for scenarios such as high-speed material impact and dynamic mechanical property testing in extreme environments.

[0108] In some embodiments of this application, the main coil 3 adopts a "multi-sub-coil array winding in the same plane" topology, and the specific parameters and structure are as follows:

[0109] Topology decomposition rule: Decompose into M independent sub-coils (M≥2, preferably M=3 or 4), with the number of turns of each sub-coil n=N / M.

[0110] Sub-coil structure: Each sub-coil is made of high-conductivity copper (conductivity ≥98% IACS, tensile strength ≥320MPa) and wire-cut into a "planar spiral" structure with a cross-sectional dimension of 10mm × 3mm (length × width); they are symmetrically arrayed in the same plane (e.g., Figure 2 The coil consists of four sub-coils: the first positive pole 211 to the first negative pole 212, the second positive pole 221 to the second negative pole 222, the third positive pole 231 to the third negative pole 232, and the fourth positive pole 241 to the fourth negative pole 242.

[0111] Spacing and insulation: The spacing between adjacent sub-coils is fixed at 1.4mm (including a 0.5mm composite insulation layer). The insulation layer adopts an epoxy resin composite structure (breakdown field strength ≥25kV / mm) to ensure that there is no electromagnetic interference between the sub-coils.

[0112] Electrode design: Each sub-coil has independent electrodes at both ends, such as... Figure 2 As shown, the electrodes are all connected to the wires using laser welding (contact resistance ≤0.08mΩ).

[0113] In some embodiments of this application, current enhancement and trapezoidal stress wave synthesis are achieved through "independent capacitor bank + high-precision timing triggering", specifically including the following configuration:

[0114] Configuration of capacitor 2: Each sub-coil is connected to an independent energy storage capacitor module. The type of capacitor 2 can be selected as "direct discharge type" (capacity 50~500μF, voltage 10~50kV, step accuracy ±0.01kV) or "indirect energy storage and release type" (including inductance compensation module, inductance value 50~100nH).

[0115] Timing-triggered control: Controller 1 adopts an FPGA controller (delay time resolution ≤10ns, jitter <1ns), which supports two modes: synchronous discharge and time-division discharge.

[0116] Synchronous discharge: All sub-coils are triggered simultaneously (discharge time difference < 10ns), total current Itotal = K represents the sequence number of the sub-coil. Since there are M sub-coils in total, the maximum value of K is M. Let F represent the discharge current of the Kth conducting sub-coil; the Lorentz force F∝Itotal², maximizing the force value.

[0117] Time-sharing discharge: By adjusting the discharge delay time of the sub-coil k ( With k > 10 ns and the delay difference between adjacent sub-coils being 50~200 μs, the half-sine stress waves generated by each sub-coil are superimposed in an orderly manner to generate a perfect trapezoidal stress wave (rising edge ≤ 50 μs, plateau pulse width 200~500 μs, falling edge ≤ 50 μs).

[0118] Waveform control logic: By adjusting the number of sub-coils M, the voltage of capacitor 2, and the discharge delay time. k can achieve: synchronous discharge of 4 sub-coils, maximizing Lorentz force; time-sharing discharge of 4 sub-coils ( 1 = 0 μs, 2 = 100 μs, 3 = 200 μs 4=300μs), generating a wide plateau trapezoidal wave; 3 sub-coils and differentiated voltages (V1=30kV, V2=25kV, V3=20kV), generating a stepped trapezoidal wave.

[0119] In some embodiments of this application, the multi-parallel coil electromagnetic Hopkinson rod 0 has a global anti-instability design: 0.2mm thick fiberglass cloth (tensile strength ≥800MPa) is attached to the upper and lower surfaces of each sub-coil and epoxy resin is injected and cured to suppress coil deformation caused by electromagnetic force (cumulative deformation ≤0.1mm).

[0120] In some embodiments of this application, experiments were conducted on the multi-parallel coil electromagnetic Hopkinson bar and cooperative control method proposed in this application, as well as other current related technologies, to verify performance indicators.

[0121] For example, the comparison results of performance indicators can be shown in Table 1 below:

[0122]

[0123] In the embodiments of this application, the Lorentz force enhancement mechanism is as follows: When the planar multi-sub-coils discharge synchronously, the current superposition effect increases the total current to 2.92 times that of the traditional radial series 4-group. According to the Lorentz force formula F=BIL, the force value increases with the square of the current, so the Lorentz force is increased to 5.95 times that of the traditional radial series 4-group. Magnetic field uniformity optimization: The planar array arrangement improves the uniformity of the magnetic field distribution on the specimen contact surface (the difference in field strength between the edge and the center is ≤10%, compared to 45% for the traditional radial series 4-group), and the effective action area is expanded to 550% (compared to 180% for the traditional radial series 4-group). Superiority of trapezoidal stress wave: Through time-division discharge (delay difference of 100μs), after the half-sine waves generated by the 4 sub-coils are superimposed, the pulse width of the trapezoidal wave plateau segment reaches 300μs (compared to 150μs for the traditional radial series 4-group), and the fluctuation is only ±3% (compared to ±15% for the traditional radial series 4-group), meeting the constant strain rate loading requirements of ductile materials (such as titanium alloys and aluminum alloys).

[0124] For example, such as Figure 4 As shown, this is a top view of the main coil 3. The main coil 3 is composed of four sub-coils located on the same plane arranged in a symmetrical ring array. Based on the top view, the winding method and spacing of the sub-coils distributed in a "planar spiral" manner can be seen.

[0125] For example, such as Figure 5 As shown, each sub-coil in the main coil 3 is connected to a corresponding independent capacitor. For example, there are four sub-coils: sub-coil A, sub-coil B, sub-coil C, and sub-coil D. The positive terminal of sub-coil A can be connected to the positive terminal of the first capacitor 201, and the negative terminal of sub-coil A can be connected to the negative terminal of the first capacitor 201. The positive terminal of sub-coil B can be connected to the positive terminal of the second capacitor 202, and the negative terminal of sub-coil B can be connected to the negative terminal of the second capacitor 202. The positive terminal of sub-coil C can be connected to the positive terminal of the third capacitor 203, and the negative terminal of sub-coil C can be connected to the negative terminal of the third capacitor 203. The positive terminal of sub-coil D can be connected to the positive terminal of the fourth capacitor 204, and the negative terminal of sub-coil D can be connected to the negative terminal of the fourth capacitor 204.

[0126] In some embodiments of this application, each sub-coil is made of high-conductivity copper with a conductivity of 98% IACS, a tensile strength of 320MPa, and IACS being the International Annealed Copper Standard. The cross-section is 10mm × 3mm. The capacitor 2 has a capacitance of 150μF and a voltage of 30kV. Each group of capacitors 2 can be connected in series with a 50nH inductor compensation module. The spacing between adjacent sub-coils is 1.4mm (including a 0.5mm composite insulation layer).

[0127] In some embodiments of this application, the inductance compensation module can suppress current oscillations, make the magnetic field and Lorentz force more stable, correct the current waveform, make the stress wave a regular trapezoid, and prevent instantaneous changes in current, thus avoiding instantaneous impact damage to capacitor 2 or coil.

[0128] In some embodiments of this application, the multi-parallel coil electromagnetic Hopkinson rod 0 may also include an incident rod.

[0129] For example, before performing the test, the structure of the multi-parallel coil electromagnetic Hopkinson bar 0 can be assembled first, and the four sub-coils can be arranged as follows: Figure 2 and Figure 3 The planar array shown is arranged with an adjacent spacing of 1.4 mm and filled with epoxy resin for curing. The positive terminal of the sub-coil is connected to the positive terminal of the capacitor bank via laser welding, and the negative terminal is connected to the negative terminal of the capacitor bank. The output terminal of the FPGA controller is connected to the trigger terminal of the capacitor bank. Next, the circuit is debugged. The four capacitor banks are charged to 30 kV. The trigger mode is set to "synchronous discharge" (delay time difference < 10 ns) through the FPGA controller. The insulation resistance between the sub-coils is checked to be ≥ 100 MΩ to ensure no short circuit. Then, a loading test is performed. The FPGA controller is triggered, and the four capacitor banks discharge simultaneously. The sub-coils generate a total current of 350 kA and generate a Lorentz force of 12.5 MN. The stress wave signal is collected by strain gauges on the surface of the incident rod (TC4 titanium alloy, radius 7 mm). The trapezoidal stress wave parameters are recorded: rise time 45 μs, plateau pulse width 300 μs, fall time 42 μs, plateau fluctuation ± 2.8%. The test is repeated 10 times. The peak fluctuation of the Lorentz force is ≤ 3%, the repeatability error of the stress wave waveform is ≤ 2%, and the system temperature rise is 75℃, which meets the requirements of high-energy impact experiments.

[0130] In some embodiments of this application, such a multi-parallel coil electromagnetic Hopkinson bar may include a planar multi-parallel main coil, a distributed capacitor module, an FPGA controller, and an anti-instability component; the planar multi-parallel main coil consists of M independent sub-coils arranged in an array on the same plane, M≥2, and the number of turns of each sub-coil n=N / M; the sub-coils are made of copper and have a "planar spiral" structure, with the spacing between adjacent sub-coils fixed at 1.4mm, and the spacing is filled with a composite insulation layer; the distributed capacitor module includes M groups of independent capacitors, each group of capacitors is connected to one sub-coil; the FPGA controller is used to control the discharge time of the M groups of capacitors, with a discharge time difference >10ns; the anti-instability component includes a fiberglass cloth reinforcement layer.

[0131] In some embodiments of this application, the sub-coil has a cross-sectional dimension of 10mm×3mm, is made of high-conductivity copper with a conductivity ≥98%IACS and a tensile strength ≥320MPa; the composite insulation layer is an epoxy resin structure with a breakdown field strength ≥25kV / mm.

[0132] In some embodiments of this application, the capacitor type of the distributed capacitor module is either direct discharge type or indirect energy storage and release type; the capacitance of the direct discharge type capacitor is 50~500μF and the voltage is 10~50kV; the indirect energy storage and release type capacitor is connected in series with an inductor compensation module of 50~100nH.

[0133] In some embodiments of this application, the fiberglass cloth reinforcement layer in the anti-instability component has a thickness of 0.2 mm and a tensile strength ≥ 800 MPa.

[0134] In some embodiments of this application, when testing using the multi-parallel coil electromagnetic Hopkinson rod 0 with the above-described structure, the FPGA controller can be triggered when it is determined that all M groups of capacitors 2 are charged to the set voltage. The controller instructs the M groups of capacitors 2 to discharge according to the set synchronous discharge or time-sharing discharge mode. The sub-coils generate current superposition effect, generating Lorentz force and trapezoidal stress wave. The stress wave signal is collected by strain gauges to complete the loading test.

[0135] In some embodiments of this application, the discharge time difference in the synchronous discharge mode is <10ns, and the total current Itotal = K represents the sequence number of the sub-coil. Since there are M sub-coils in total, the maximum value of K is M. This represents the discharge current of the Kth conducting sub-coil; the synchronous discharge mode is used to maximize the Lorentz force, and the time-sharing discharge mode has a discharge delay difference of 50~200μs between adjacent sub-coils, which is used to generate trapezoidal stress waves.

[0136] In some embodiments of this application, the rising edge of the trapezoidal stress wave is ≤50μs, the pulse width of the plateau segment is 200~500μs, the falling edge is ≤50μs, and the plateau segment fluctuation is ≤±3%.

[0137] In some embodiments of this application, the planar multi-parallel main coil in the multi-parallel coil electromagnetic Hopkinson rod 0 can be replaced with a non-planar multi-parallel main coil, and the number of sub-coils M ≥ 2.

[0138] In the embodiments of this application, the structure of the above-mentioned multi-parallel coil electromagnetic Hopkinson rod 0 and the loading test performed using the structure can be used for aerospace composite material delamination testing, dynamic response analysis of nuclear industry structural components, or impact resistance performance evaluation of armor materials.

[0139] In this embodiment, the functional modules can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional module.

[0140] If the integrated unit is implemented as a software functional module and is not sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this embodiment, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) or processor to execute all or part of the steps of the method of this embodiment.

[0141] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of hardware embodiments, software embodiments, or embodiments combining software and hardware aspects. Furthermore, this application can take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk storage and optical storage) containing computer-usable program code.

[0142] This application is described with reference to schematic and / or block diagrams illustrating the implementation of methods, apparatus (systems), and computer program products according to embodiments of this application. It should be understood that each step and / or block in the schematic and / or block diagrams, as well as combinations thereof, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, produce functions for implementing one or more steps in the schematic diagrams and / or the functions specified in one or more blocks in the block diagrams.

[0143] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means that implement the function specified in one or more processes in an implementation flow diagram and / or one or more blocks in a block diagram.

[0144] These computer program instructions can also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0145] The above embodiments are merely preferred embodiments provided to fully illustrate this application, and the scope of protection of this application is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on this application are all within the scope of protection of this application.

Claims

1. A multi-parallel coil electromagnetic Hopkinson rod, characterized in that, include: A controller used to control the discharge time of multiple capacitors; The plurality of capacitors are respectively used to discharge according to the discharge time; The main coil is used to generate a corresponding target Lorentz force in response to the discharge of the capacitor, so as to apply an impact load to the test piece using the target Lorentz force and complete the dynamic mechanical property test of the test piece. The main coil comprises multiple sub-coils arranged in a symmetrical ring array, with a spacing of 1.4 mm between each sub-coil. A 0.5 mm composite insulation layer, made of epoxy resin, is provided between adjacent sub-coils. Each sub-coil has a ring-shaped spiral structure, and any two adjacent sub-coils are different sub-coils. Anti-instability components are attached to two opposing surfaces of each sub-coil. These anti-instability components are 0.2 mm thick glass fiber cloth reinforcement layers with a tensile strength ≥800 MPa, cured by epoxy resin injection. Each capacitor is connected to its corresponding sub-coil.

2. The multi-parallel coil electromagnetic Hopkinson rod according to claim 1, characterized in that, Also includes: The composite insulation layer is used to achieve insulation isolation between adjacent sub-coils.

3. The multi-parallel coil electromagnetic Hopkinson rod according to claim 2, characterized in that, Also includes: The anti-instability component is used to suppress the deformation of the sub-coil under the action of Lorentz force.

4. The multi-parallel coil electromagnetic Hopkinson rod according to claim 3, characterized in that, Each sub-coil is provided with positive and negative electrodes to achieve electrical connection between the sub-coil and the capacitor; The positive terminal of the sub-coil is connected to the positive terminal of the capacitor, and the negative terminal of the sub-coil is connected to the negative terminal of the capacitor.

5. The multi-parallel coil electromagnetic Hopkinson rod according to claim 4, characterized in that, The capacitor is a direct discharge type capacitor or an indirect energy storage and release type capacitor; The direct discharge capacitor is used to directly output pulse current; The indirect energy storage and release capacitor is connected in series with an inductor compensation module, which is used to optimize the pulse current waveform.

6. The multi-parallel coil electromagnetic Hopkinson rod according to any one of claims 1 to 5, characterized in that, The multiple sub-coils arranged in a symmetrical ring array in the main coil are located on the same plane; or, the multiple sub-coils are not located on the same plane.

7. The multi-parallel coil electromagnetic Hopkinson rod according to claim 6, characterized in that, The number of turns of each sub-coil is equal to the ratio of the total number of turns of the main coil to the number of sub-coils.

8. A cooperative control method, characterized in that, An electromagnetic Hopkinson bar with multiple parallel coils as described in any one of claims 1 to 7 is provided, wherein the electromagnetic Hopkinson bar with multiple parallel coils includes a controller, multiple capacitors, and a main coil; the main coil includes multiple sub-coils arranged in a symmetrical ring array, the spacing between each sub-coil is 1.4 mm, and a 0.5 mm composite insulation layer, which is epoxy resin, is provided between adjacent sub-coils; each sub-coil has a ring spiral structure, and any two adjacent sub-coils are different sub-coils; an anti-instability component is attached to two opposing surfaces of each sub-coil, the anti-instability component being a 0.2 mm thick glass fiber cloth reinforcement layer with a tensile strength ≥800 MPa, the glass fiber cloth reinforcement layer being cured by injecting epoxy resin; The plurality of capacitors are respectively connected to the plurality of sub-coils; the method includes: The controller sends a discharge control signal to the plurality of capacitors, so that the plurality of capacitors discharge in response to the discharge control signal; The main coil responds to the discharge of the multiple capacitors to generate a corresponding target Lorentz force, and the target Lorentz force is used to apply an impact load to the test piece to complete the dynamic mechanical performance test of the test piece.

9. The cooperative control method according to claim 8, characterized in that, The step of generating a corresponding target Lorentz force by responding to the discharge of the plurality of capacitors through the main coil includes: When the discharge control signal is a synchronous discharge control signal, the target Lorentz force is generated by the main coil responding to the synchronous discharge of the multiple capacitors, based on the total current formed by the superposition of the currents of each sub-coil.

10. The cooperative control method according to claim 8, characterized in that, The step of generating a corresponding target Lorentz force by responding to the discharge of the plurality of capacitors through the main coil includes: When the discharge control signal is a time-sharing discharge control signal, the main coil responds to the time-sharing discharge of the multiple capacitors according to a preset delay time, and the Lorentz forces generated by each sub-coil are superimposed based on the preset delay time to obtain the target Lorentz force.

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