Impact mechanics loading device and method based on electromagnetic coil transmitter block test

Abstract

The present application relates to material dynamic mechanical property testing technology, and specifically relates to an impact mechanical loading device and method based on electromagnetic coil transmitter locked-rotor test, the device comprising a pulse power module, an electromagnetic loading module, a constraint fixing module and a measurement and control system; the upper computer is used for setting the capacitor charging voltage, controlling the switch to conduct to discharge the electromagnetic loading module to generate pulse current, the electromagnetic coil generates pulse magnetic field to make the conductor armature induction eddy current to generate axial electromagnetic force; the rigid constraint armature position forms locked-rotor, the impact electromagnetic force is directly loaded on the sample through the impact head to form impact stress, and the working performance of monitoring devices such as voltage, current and impact force is monitored to carry out dynamic response, fatigue damage and aging accumulation experiments of materials. The device has the advantages of small volume, flexible adjustable impact stress wavelength and amplitude, high efficiency and the like, and solves the problems of large volume, difficult control of impact stress pulse width and low test efficiency of traditional mechanical impact devices.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of material dynamic mechanical property testing, and particularly relates to an impact mechanical loading device and method based on a locked-rotor test of an electromagnetic coil transmitter. BACKGROUND

[0002] Traditional impact test devices mainly include a drop hammer type tester and a Hopkinson bar. The drop hammer type tester realizes material impact resistance performance testing through free fall impact, and is suitable for evaluating the external impact resistance performance of engineering materials such as PVC-U pipes and PE plates. The Hopkinson bar device is based on one-dimensional elastic stress wave theory, and can realize dynamic mechanical property testing in a strain rate range of 100 s -1 ~10000 s -1 , and is widely used in mechanical response analysis of materials under dynamic compression, tension and torsion load conditions.

[0003] However, the traditional impact test device has the following limitations:

[0004] (1) Traditional mechanical impact devices (such as drop hammer type and Hopkinson bar) usually rely on heavy mechanical structures and have a large volume;

[0005] (2) The existing dynamic energy impact test device based on electromagnetic emission principle has the problem that the impact stress pulse width is not convenient to control and some are too short (μs level), which is mismatched with the ms level long pulse width stress borne by the transmitter cylinder wall in the actual electromagnetic emission scene, and cannot truly simulate the dynamic mechanical response of the cylinder wall material;

[0006] (3) High repetition frequency fatigue damage testing is limited by the mechanical structure reset efficiency, and it is difficult to meet the high frequency loading test demand of material fatigue cumulative effect.

[0007] Existing electromagnetic emission technology focuses on armature kinetic energy output, and has not applied the impact electromagnetic force loading mechanism under the locked-rotor constraint state to material dynamic stress wave response testing. Therefore, a new impact test device with adjustable stress pulse width and amplitude, supporting high repetition frequency loading, is needed to solve the technical defects of traditional devices in long pulse width load simulation and high frequency fatigue testing. SUMMARY

[0008] The application provides an impact mechanical loading device and method based on a locked-rotor test of an electromagnetic coil transmitter, which aims at the technical bottlenecks of large structure volume, low repetition frequency test efficiency, and inconvenient stress pulse width control of the traditional impact test in the prior art, realizes high-precision repetition frequency testing of material dynamic response characteristics, fatigue damage evolution and aging cumulative effect through a pulse electromagnetic force loading mechanism.

[0009] The application provides an impact mechanics loading device based on electromagnetic coil transmitter blockage test, comprising a pulse power supply module 101, an electromagnetic loading module 102, a sample 103, a constraint fixing module 104 and a measurement and control system 105; the measurement and control module 105 is sequentially connected with the pulse power supply module 101, the electromagnetic loading module 102 and the constraint fixing module 104, and the sample 103 is placed in the electromagnetic loading module 102.

[0010] The pulse power supply module 101 comprises a pulse capacitor 1011, a closed switch 1012, a charging machine 1013 and a freewheeling diode 1014, and is used for single or repeated frequency pulse discharge and continuous oscillation decay pulse discharge.

[0011] The electromagnetic loading module 102 comprises a coil 1021, a conductor armature 1022 and an impact head 1023.

[0012] The constraint fixing module 104 comprises a front steel frame 1041, a rear steel frame 1042, a horizontal steel plate 1043 and an insulating bottom column 1044, and is used for limiting the displacement of the armature.

[0013] The measurement and control system 105 comprises an upper computer 1051, a pressure sensor 1052, a voltage sensor 1053 and a current sensor 1054, and is used for monitoring and controlling pulse parameters.

[0014] According to the impact mechanics loading device based on electromagnetic coil transmitter blockage test, the charging machine 1013 is connected with both ends of the pulse capacitor 1011 to charge the pulse capacitor 1011, and after the pulse capacitor 1011 reaches the rated voltage, the closed switch 1012 is controlled to discharge the coil 1021, and the upper computer 1051 controls the charging machine 1013.

[0015] According to the impact mechanics loading device based on electromagnetic coil transmitter blockage test, when the freewheeling diode 1014 is reversely connected in parallel with both ends of the pulse capacitor 1011, a single-peak pulse waveform is formed; if the freewheeling diode 1014 is not connected, a continuous oscillation decay pulse waveform is formed.

[0016] According to the impact mechanics loading device based on electromagnetic coil transmitter blockage test, the conductor armature 1022 is placed in the coil 1021 after being raised by the insulating bottom column 1044; the impact electromagnetic force can be adjusted by adjusting the height of the insulating bottom column 1044, and the conductor armature 1022 obtains the maximum axial electromagnetic force when the bottom surface of the conductor armature 1022 is located in the middle of the coil 1021.

[0017] According to the impact mechanical loading device based on electromagnetic coil transmitter block test provided by the application, the front steel frame 1041 and the rear steel frame 1042 are vertically fixed on the upper surface of the horizontal steel plate 1043, are locked by bolts, and the spacing between the front steel frame 1041 and the rear steel frame 1042 is adjustable; the inner surface of the front steel frame 1041 is fixed with the pressure sensor 1052, the sample 103 is tightly attached to the surface of the pressure sensor 1052, and the spacing between the front and rear steel frames is adjusted to ensure that the impact head 1023 is tightly attached to the sample 103; the inner surface of the rear steel frame 1042 is fixed with the coil 1021 through the bottom flange, and is used for limiting the displacement of the coil 1021 during electromagnetic loading.

[0018] According to the impact mechanical loading device based on electromagnetic coil transmitter block test provided by the application, the conductor armature 1022 comprises a cylinder 1022-1 and a circular truncated cone 1022-2, the upper surface of the circular truncated cone 1022-2 is provided with a cylindrical groove 1022-3 for placing the impact head 1023; the impact head 1023 is connected with the cylindrical groove 1022-3 in an interference fit; the impact head 1023 is made of high-strength steel, and the impact head 1023 comprises a round head, a flat head or other shapes; the round head armature is composed of a hemisphere 1023-11 with a diameter of d and a cylindrical handle 1023-12 with a bottom surface diameter d2 and a height h; the flat head armature is composed of a cylinder 1023-21 with a diameter of d and a cylindrical handle 1023-22 with a bottom surface diameter d2 and a height h.

[0019] According to the impact mechanical loading device based on electromagnetic coil transmitter block test provided by the application, the measurement and control module 105 is internally provided with a pulse parameter feedback module, a voltage sensor 1053 and a current sensor 1054, which are used for monitoring the voltage amplitude and the current waveform, and the pressure sensor 1052 is used for monitoring the impact force waveform.

[0020] The application also provides an impact mechanical loading method based on electromagnetic coil transmitter block test, which sets the capacitor charging voltage through the upper computer 1051, controls the charging and discharging of the pulse power module 101 to generate transient pulse current, generates a pulse magnetic field through the coil 1021, makes the conductor armature 1022 generate eddy current to generate axial impact electromagnetic force, the pulse width can be adjusted by changing the capacitance value of the pulse capacitor 1011 and the inductance value of the coil 1021, the adjustment range is μs~ms level, the amplitude can be adjusted by changing the charging voltage value of the pulse capacitor 1011, the material and structure of the armature, and the axial relative position of the bottom surface of the conductor armature 1022 and the center line of the coil 1021; the position of the conductor armature 1022 is locked by rigid constraint to form block, the impact electromagnetic force generated on the conductor armature 1022 is directly loaded to the sample 103 through the impact head 1023, the test of the dynamic response, fatigue damage and aging accumulation of the material is realized; the specific steps are as follows:

[0021] S1 determines whether to install a freewheeling diode 1014 according to the type of the required impact force, and determines the corresponding pulse capacitor, coil inductance and charging voltage according to the pulse width and amplitude of the required impact force;

[0022] S2 charges the pulse capacitor to a voltage controlled by the upper computer 1051; U 0;

[0023] S3 after the charging is completed, the upper computer 1051 controls the closing of the switch 1012 to be conductive, and the pulse power module 101 discharges to the coil 1021 to generate a pulse current;

[0024] S4 the conductor armature 1022 induces eddy current to generate an axial electromagnetic force, the direction of which is perpendicular to the surface of the sample 103 and close to the sample 103, and the electromagnetic force is directly loaded to the sample 103 through the impact head 1023;

[0025] S5 the dynamic mechanical response is monitored by the pressure sensor 1052, and the impact waveform is displayed;

[0026] S6 after the single impact loading is completed, the process is stopped;

[0027] S7 repeats S1-S6, and through setting the number of loadings and the frequency, the periodic repeated impact fatigue loading test is carried out.

[0028] The application also provides an electronic device, which comprises a memory, a processor and a computer program stored in the memory, and the processor executes the computer program to realize the steps of the impact mechanical loading method based on the electromagnetic coil transmitter stall test.

[0029] The application also provides a computer readable storage medium, which stores a computer program / instruction, and the computer program / instruction is executed by the processor to realize the steps of the impact mechanical loading method based on the electromagnetic coil transmitter stall test.

[0030] The application also provides an electronic device, which comprises a memory, a processor and a computer program stored in the memory, and the processor executes the computer program to realize the steps of the pulse electromagnetic force loading method based on the electromagnetic stall principle.

[0031] The application also provides a computer readable storage medium, which stores a computer program / instruction, and the computer program / instruction is executed by the processor to realize the steps of the impact mechanical loading method based on the electromagnetic coil transmitter stall test.

[0032] Compared with the prior art, the beneficial effects of the present application are: the present application provides an impact mechanics loading device based on electromagnetic coil transmitter blocking test, which can be used in the field of material dynamic mechanics performance test technology, and provides a more efficient method for in-depth study of material dynamic impact, damage and aging accumulation. The method realizes flexible control of the pulse stress waveform of dynamic mechanics loading, significantly improves the test efficiency and data reliability. Flexible and adjustable, supporting single high-energy impact (such as explosion simulation) and high-frequency repeated loading (fatigue damage research); the device converts pulse electromagnetic energy into internal stress wave of the sample by rigidly restraining the armature displacement, and realizes dynamic mechanics test. The conductor armature and the impact head support rapid replacement, adapt to different test scenes; at the same time, the modular design and control meet the needs of various actual working conditions. The device of the present application is suitable for the test needs of composite materials, metal alloys, polymer materials and the like in high strain rate impact, fatigue damage and aging accumulation research. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the present application or prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0034] Figure 1 is a schematic diagram of the module connection relationship of the impact mechanics loading device based on electromagnetic coil transmitter blocking test provided by the embodiment of the present application with freewheel diode;

[0035] Figure 2 is a schematic diagram of the connection relationship of the module of the impact mechanics loading device based on electromagnetic coil transmitter blocking test provided by the embodiment of the present application without freewheel diode;

[0036] Figure 3 is a specific physical model schematic diagram of the electromagnetic loading module 102 and the constraint fixing module 104 provided by the embodiment of the present application;

[0037] Figure 4 is a schematic diagram of the split structure of the conductor armature 1022 and the impact head 1023 provided by the embodiment of the present application;

[0038] Figure 5 is a comparison diagram of electromagnetic blocking pulse electromagnetic force waveforms under different excitation voltage value settings when the capacitance value is fixed provided by the embodiment of the present application;

[0039] Figure 6 is a comparison diagram of magnetic blocking pulse electromagnetic force waveforms under different capacitance value settings when the excitation voltage value is fixed provided by the embodiment of the present application;

[0040] Figure 7 is an electromagnetic stall pulse electromagnetic force oscillation decay waveform diagram provided by an embodiment of the present application under a certain capacitance value and excitation voltage value setting;

[0041] Figure 8 is a structural schematic diagram of an electronic device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0042] To make the objectives, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described below in detail with reference to the drawings in the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0043] As shown in Figure 1 , the present embodiment is implemented by the following technical solutions, an impact mechanics loading device based on electromagnetic coil transmitter stall test, comprising a measurement and control module 105, a pulse power supply module 101, an electromagnetic loading module 102, a sample 103 and a constraint fixing module 104 connected in sequence. The measurement and control module 105 is connected to the pulse power supply module 101, the electromagnetic loading module 102 and the constraint fixing module 104 in sequence, and the sample 103 is placed in the electromagnetic loading module 102.

[0044] Among them, the pulse power supply module 101 includes a pulse capacitor 1011, a closed switch 1012, a charging machine 1013 and a freewheeling diode 1014, which is used for single or repeated frequency pulse discharge;

[0045] The electromagnetic loading module 102 includes a coil 1021, a conductor armature 1022 and an impact head 1023;

[0046] The constraint fixing module 104 includes a front steel frame 1041, a rear steel frame 1042, a horizontal steel plate 1043 and an insulating column 1044, which is used for limiting the displacement of the armature;

[0047] The measurement and control system 105 includes an upper computer 1051, a pressure sensor 1052, a voltage sensor 1053 and a current sensor 1054, which is used for pulse parameter monitoring and control.

[0048] The device sets the capacitor charging voltage through the upper computer 1051, controls the pulse power supply module 101 to generate transient pulse current by charging and discharging, the electromagnetic coil generates alternating magnetic field, the conductor armature 1022 generates induced eddy current to generate axial impact electromagnetic force; the position of the conductor armature 1022 is locked by rigid constraint to form stall, the impact electromagnetic force generated on the armature is loaded to the sample 103 through the impact head, realizing high-precision test of material dynamic response, fatigue damage and aging accumulation.

[0049] Charger 1013 is connected to the pulse capacitor 1011 both ends for charging, after reaching the rated voltage control to close the switch 1012 to the coil 1021 discharge, the host computer 1051 and the charger 1013 connection, to achieve the control of the charger 1013.

[0050] As shown in Figure 1 , Figure 2 , the freewheeling diode 1014 is connected in antiparallel to the pulse capacitor 1011 both ends, forming a single peak pulse waveform. If the freewheeling diode 1014 is not connected, a continuous oscillation decay pulse waveform is formed.

[0051] As shown in Figure 3 , the conductor armature 1022 bottom is raised through the insulating column 1044 and placed in the coil 1021 to form a coil transmitter, and is packaged and formed by pouring resin material; the height of the insulating column 1044 is selected according to the height of the coil 1021, and when the bottom surface of the conductor armature 1022 is located in the middle of the coil 1021, the optimal electromagnetic induction level can be achieved, and the conductor armature 1022 obtains the maximum axial electromagnetic force.

[0052] The conductor armature 1022 and the impact head 1023 adopt a split fatigue-resistant structure, as shown in Figure 4 , the conductor armature 1022 is generally a cylinder 1022-1 and a circular truncated cone 1022-2, the upper surface of the circular truncated cone 1022-2 is provided with a cylindrical recess 1022-3 with a diameter d1 and a depth h, for placing the impact head 1023. The impact head 1023 is made of high-strength steel, and the impact head 1023 includes a flat head, a round head or other shapes; the round head armature is composed of a hemisphere 1023-11 with a diameter d and a cylindrical handle 1023-12 with a diameter d2 and a height h; the flat head armature is composed of a cylinder 1023-21 with a diameter d and a cylindrical handle 1023-22 with a diameter d2 and a height h. The front impact head 1023 and the cylindrical recess 1022-3 of the conductor armature 1022 adopt an interference fit, and d1 is slightly larger than d2.

[0053] The coil transmitter is fixed at the bottom of the rear steel frame 1042, the impact head 1023 is constrained to the front steel frame 1041, the front steel frame 1041 and the rear steel frame 1042 are fixed on the horizontal steel plate 1043 through bolts, forming a rigid frame, realizing the precise positioning and load transmission of the electromagnetic loading module 102. Moreover, the distance between the front steel frame 1041 and the rear steel frame 1042 is adjustable; the pressure sensor 1052 is fixed on the inner surface of the front steel frame 1041, and the sample 103 is tightly attached to the surface of the pressure sensor 1052, and the distance between the front and rear steel frames is adjusted to ensure that the impact head 1023 is tightly attached to the sample 103; the inner surface of the rear steel frame 1042 and the coil 1021 are connected and fixed through the bottom flange, for limiting the displacement of the coil transmitter during electromagnetic loading.

[0054] The impact head 1023 should be closely attached to the sample 103 to prevent the generation of a gap due to not being closely attached, resulting in a small acceleration movement of the armature in the axial direction when the pulse is discharged, and causing the transmission of mechanical vibration and stress waves to be not concentrated.

[0055] The surface of the impact head 1023 made of high-strength steel is subjected to nitriding treatment, which greatly increases the hardness and greatly reduces the single-impact wear rate.

[0056] The core innovation points of the present application include the following modules and technical details:

[0057] 1. Electromagnetic stress wave loading mechanism: The armature position is forced to lock by rigid constraint to form locked-rotor, and the pulse electromagnetic energy is directly converted into internal stress waves of the sample, eliminating the interference of traditional kinetic energy type impact. For example, when single pulse loading, the peak pressure of the armature head can reach 1000 MPa.

[0058] 2. Waveform parameters can be flexibly adjusted: The pulse parameters such as pulse width can be adjusted by changing the parameters of the external RLC circuit, and the adjustment range is μs~ms level. The voltage, frequency and repetition number can also be controlled by the upper computer to realize single high-energy impact or higher frequency periodic loading, and the test efficiency is high. For example, when U=1kV, the capacitance C=4mF, the single pulse energy E=0.5CU 2 =2J, and the cumulative damage can be simulated by repeating the loading for 10 times.

[0059] 3. Split design of conductor armature and impact head: The high-strength steel impact transmission head has high yield strength and hardness to ensure the plastic deformation resistance under impact load; the conductive base can be selected from metals with high electrical conductivity and high thermal conductivity to optimize the efficiency of eddy current generation while considering heat dissipation.

[0060] 4. Waveform switching of freewheeling diode double-mode operation: The freewheeling diode can generate a single-peak pulse wave when connected; when the freewheeling diode is removed, the pulse current oscillates in the RLC circuit to generate a continuous decaying oscillation wave. This mode is particularly suitable for fatigue damage testing of high-elastic polymer such as rubber, matching the relaxation time and simulating the actual vibration working condition.

[0061] Embodiment

[0062] The glass fiber / epoxy resin composite material is taken as the test object to verify the dynamic response and damage characteristics of the device under the preset number of electromagnetic pulse loadings.

[0063] Step 1: initial circuit line connection of each module, as shown in Figure 1 .

[0064] Specifically, the input end of the charger 1013 is connected to a three-phase 380V industrial power supply, and the high-voltage terminal of the output end is connected to the positive electrode of the pulse capacitor 1011 through a cable; the low-voltage terminal of the pulse capacitor 1011 is grounded through the closed switch 1012, and the switch signal line is connected to the PWM control port of the upper computer 1051; a continuous current diode 1014 is connected in parallel to the high-voltage terminal of the pulse capacitor 1011, which is used to suppress reverse current.

[0065] Step 2: The sample 103 in the electromagnetic loading module 102 and the constraint fixing module 104 is installed and positioned, and the adjustment step is as shown in Figure 3

[0066] Specifically, the glass fiber / epoxy resin laminate sample is prepared with a 0° / 90° layer, a diameter of 80mm, and a thickness of 2mm. After cutting and polishing, the edge is chamfered by 0.5mm to avoid stress concentration; as shown in Figure 3 The sample 103 is placed in the circular sample groove 1044, the insulating column 1044 is placed in the coil 1021, and then the conductor armature 1022 is placed in the coil 1021. The front steel frame with the sample is moved to the surface of the sample to tightly contact the impact head 1023. The inside of the rear steel frame 1042 is provided with a coil 1021 mounting seat, and the coil 1021 bottom is fixed by flange connection. All the fixing devices are placed on the horizontal steel plate 1043 to ensure that the front steel frame 1041 and the coil 1021 are horizontally coaxial and collinear. The device is rigidly connected through bolt fixing limiting holes.

[0067] Step 3: The electromagnetic pulse parameter setting and loading execution step.

[0068] Specifically, the target parameters are input into the upper computer 1051, and different capacitor voltages U0 can be set. Taking the capacitor voltage U0=1.5kV as an example, in the case of RLC circuit parameters C=4mF, L=63μH, R=16mΩ, the actual pulse width can be adjusted according to the need to obtain different pulse widths. The RLC circuit parameters are set to periodic cycle loading mode, and the number of loadings is determined according to the specific test requirements. In this embodiment, 50 loadings are taken as an example.

[0069] The upper computer 1051 clicks the "Start" button, the charger 1013 charges the pulse capacitor 1011, and the real-time display of the charging voltage and current curve is realized. The real-time display of the voltage across the pulse capacitor 1011 is realized, and after the charging is completed, the system triggers the automatic stop charging indication, and the closed switch 1012 is actively triggered. The pulse capacitor 1011 is discharged through the coil 1021, and the oscilloscope records the pulse current peak value of about 8kA and the waveform.

[0070] ​The conductor armature 1022 induces eddy currents to generate axial electromagnetic force, which is sampled by a pressure sensor and recorded as a peak electromagnetic force of approximately 18 kN and waveform. The conductor armature 1022 and the impact head 1023 are constrained by a rigid base column and front and rear steel frames, and their positions are locked. The electromagnetic energy is converted into stress waves in the sample.

[0071] In addition, the specific implementation also includes, for example Figure 2 As shown, when no freewheeling diode is connected in the circuit, the pulse current generates an underdamped oscillation in the RLC circuit. When the pulse capacitor capacitance is set to 4mF and the excitation voltage is set to 1500V, the following occurs: Figure 7 The continuously decaying oscillating wave shown is an example. This waveform has multiple complete oscillation cycles, causing the specimen to be subjected to multi-cycle stress within a single loading, simulating actual vibration conditions.

[0072] In addition, during the implementation process, comparative tests were conducted using the same operating methods and with different excitation voltages and capacitance values. Figure 5 This is a comparison diagram of the impact electromagnetic force waveforms under different excitation voltage settings when the capacitance value is fixed in this embodiment. Figure 6 This is a comparison of the impulse electromagnetic force waveforms under different capacitance values ​​when the excitation voltage is fixed in this embodiment. The pulse width is defined using the commonly used full width at half maximum (FWHM) mode, which is the time interval between the electromagnetic force rising from 50% of its peak value to the peak value and then falling back to 50% of its peak value.

[0073] With fixed capacitance and other circuit parameters, voltage and peak electromagnetic force are positively correlated. When the voltage increases from 500V to 1500V, the peak electromagnetic force increases from 8kN to 18kN, and the pulse width is consistent. The full width at half maximum (FWHM) of the pulse remains at 0.6ms under different voltages, indicating that the pulse width is dominated by capacitance and circuit parameters and is independent of voltage.

[0074] With fixed excitation voltage and other circuit parameters, the capacitance values ​​were 1mF, 4mF, and 10mF, respectively. The pulse width (FWHM) increased from 400μs to 1ms, demonstrating a positive correlation between pulse width and capacitance value. Furthermore, by adjusting the circuit coil inductance, the pulse width can be precisely controlled in the μs to ms range to match the actual stress duration on the electromagnetic transmitter's cylinder wall, providing realistic load conditions for material fatigue damage research.

[0075] Step 4: Termination of dynamic impact loading experiment and test and analysis of sample results.

[0076] Specifically, after reaching the set number of stall loads, the experiment is stopped, the discharge resistor is connected to the capacitor terminal, the voltage drops to a safe range within 3 seconds, the high-frequency charger is turned off, the power supply is turned off, and the circuit connection is disconnected.

[0077] The sample surface condition can be preliminarily observed macroscopically, a small area of about 3-4 mm in diameter is depressed, the area is white in color, and there is no delamination phenomenon. The average impact strength is 40 kJ / m 2 The micro-morphology of the impact area, fiber fracture and matrix debonding can be observed by a scanning electron microscope (SEM).

[0078] This embodiment fully demonstrates the whole process of the electromagnetic stall test impact device from system initialization, sample installation, parameter setting, dynamic loading to damage evaluation by setting electromagnetic pulse loading under different capacitor voltages. This embodiment verifies the efficiency and accuracy of the present application in the current material dynamic mechanical test, and lays a technical foundation for further high-frequency fatigue, multi-pulse superposition and other complex working condition research.

[0079] This embodiment also provides an impact mechanics loading method based on the electromagnetic coil transmitter stall test, which is suitable for an impact mechanics loading device based on the electromagnetic coil transmitter stall test. The method sets the capacitor charging voltage through the upper computer 1051, controls the charging and discharging of the pulse power module 101 to generate a transient pulse current, generates a pulse magnetic field through the coil 1021, makes the conductor armature 1022 induce eddy current to generate axial impact electromagnetic force, the pulse width can be adjusted by changing the capacitance value of the pulse capacitor 1011 and the inductance value of the coil 1021, the adjustment range is μs-ms level, the amplitude can be adjusted by changing the charging voltage value of the pulse capacitor 1011, the material and structure of the armature, and the axial relative position of the bottom surface of the conductor armature 1022 and the center line of the coil 1021; the position of the conductor armature 1022 is locked by rigid constraint to form stall, the impact electromagnetic force generated on the conductor armature 1022 is directly loaded to the sample 103 through the impact head 1023, and the test of material dynamic response, fatigue damage and aging accumulation is realized; the specific steps are as follows:

[0080] S1 determines whether to install a freewheeling diode 1014 according to the type of impact force required for loading, determines the corresponding pulse capacitor, coil inductance and charging voltage and other parameters according to the pulse width and amplitude of the impact force required;

[0081] S2 controls the pulse capacitor to charge to U 0 through the upper computer 1051;

[0082] S3 after charging, controls the switch 1012 to be closed and conductive through the upper computer 1051, the pulse power module 101 discharges to the coil 1021 to generate a pulse current;

[0083] S4 the conductor armature 1022 induces eddy current to generate axial electromagnetic force, the direction is perpendicular to the surface of the sample 103 and closely contacts the sample 103, the electromagnetic force is directly loaded to the sample 103 through the impact head 1023;

[0084] S5 monitors the impact force waveform through the pressure sensor 1052;

[0085] S6 stops after the single impact loading is completed;

[0086] S7 repeats S1-S6, and by setting the number of loadings and the frequency, periodic repeated impact loading tests can be performed.

[0087] Figure 8 An example of a schematic diagram of the physical structure of an electronic device is shown in Figure 8 As shown, the electronic device can include a processor, a communications interface, a memory, and a communications bus, wherein the processor, the communications interface, and the memory complete mutual communication through the communications bus. The processor can invoke logical instructions in the memory to execute an impact mechanics loading method based on electromagnetic coil transmitter stall testing.

[0088] In addition, the logical instructions in the memory described above can be implemented in the form of a software functional unit and sold or used as an independent product, and can be stored in a computer-readable storage medium. Based on such understanding, the technical solutions of the present application essentially or the part that contributes to the prior art or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium, and includes a number of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, and various media that can store program codes.

[0089] In yet another aspect, the present application also provides a non-transitory computer-readable storage medium having a computer program stored thereon, the computer program being executed by a processor to implement the impact mechanics loading method based on electromagnetic coil transmitter stall testing provided by the above-mentioned methods.

[0090] The device embodiments described above are only schematic, wherein the units shown as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, i.e., they can be located in one place, or distributed on multiple network units. Part or all of the modules can be selected to achieve the purpose of the present embodiment scheme according to actual needs. Those skilled in the art can understand and implement it without creative labor.

[0091] Those skilled in the art can clearly understand the implementation of the embodiments by means of software and necessary general hardware platforms through the description of the above embodiments, and the embodiments can also be implemented by hardware. Based on such understanding, the above technical solutions can be embodied in the form of a software product, and the computer software product can be stored in a computer readable storage medium, such as a ROM / RAM, a magnetic disk, an optical disk, etc., and includes a plurality of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute the methods described in each embodiment or some parts of the embodiments.

[0092] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for some technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An impact mechanics loading device based on a stalling test of an electromagnetic coil transmitter, characterized by, The device comprises a pulse power module (101), an electromagnetic loading module (102), a sample (103), a constraint fixing module (104) and a measurement and control module (105); the measurement and control module (105) is sequentially connected with the pulse power module (101), the electromagnetic loading module (102) and the constraint fixing module (104), and the sample (103) is placed in the electromagnetic loading module (102); The pulse power module (101) comprises a pulse capacitor (1011), a closed switch (1012), a charging machine (1013) and a freewheeling diode (1014), and is used for single or repeated frequency pulse discharge and continuous oscillation decay pulse discharge. The electromagnetic loading module (102) comprises a coil (1021), a conductor armature (1022) and an impact head (1023). The constraint fixing module (104) comprises a front steel frame (1041), a rear steel frame (1042), a horizontal steel plate (1043) and an insulating bottom column (1044), and is used for limiting the displacement of the armature. The front steel frame (1041) and the rear steel frame (1042) are vertically fixed on the upper surface of the horizontal steel plate (1043) and are locked by bolts, and the distance between the front steel frame (1041) and the rear steel frame (1042) is adjustable; a pressure sensor (1052) is fixed on the inner surface of the front steel frame (1041), the sample (103) is tightly attached to the surface of the pressure sensor (1052), and the distance between the front steel frame (1041) and the rear steel frame (1042) is adjusted to ensure that the impact head (1023) is tightly attached to the sample (103); the inner surface of the rear steel frame (1042) is connected and fixed with the coil (1021) through a bottom flange, and is used for limiting the displacement of the coil (1021) during electromagnetic loading. The conductor armature (1022) comprises a cylinder (1022-1) and a circular truncated cone (1022-2), and a circular cylindrical groove (1022-3) is formed on the upper surface of the circular truncated cone (1022-2) and is used for placing the impact head (1023); the impact head (1023) is connected with the circular cylindrical groove (1022-3) through interference fit; the impact head (1023) is made of high-strength steel and comprises a round head or a flat head; the round head armature is composed of a hemisphere (1023-11) with a diameter of d and a cylindrical handle (1023-12) with a bottom diameter of d2 and a height of h; the flat head armature is composed of a cylinder (1023-21) with a diameter of d and a cylindrical handle (1023-22) with a bottom diameter of d2 and a height of h; The measurement and control module (105) comprises an upper computer (1051), a pressure sensor (1052), a voltage sensor (1053) and a current sensor (1054), and is used for monitoring and controlling pulse parameters.

2. The impact mechanics loading device based on the electromagnetic coil transmitter stall test of claim 1, wherein, The charging machine (1013) is connected between the two ends of the pulse capacitor (1011) to charge the pulse capacitor (1011), and after the pulse capacitor (1011) reaches the rated voltage, the closed switch (1012) is controlled to discharge the coil (1021); the upper computer (1051) controls the charging machine (1013).

3. The impact mechanics loading device based on the electromagnetic coil transmitter stall test of claim 1, wherein, When the freewheeling diode (1014) is connected in reverse parallel with the two ends of the pulse capacitor (1011), a single-peak pulse waveform is formed; if the freewheeling diode (1014) is not connected, a continuous oscillation decay pulse waveform is formed.

4. The impact mechanics loading device based on the electromagnetic coil transmitter stall test of claim 1, wherein, The conductor armature (1022) is placed in the coil (1021) after being raised by the insulating column (1044) at the bottom; and the impact electromagnetic force is adjusted by adjusting the height of the insulating column (1044).

5. The impact mechanics loading device based on the electromagnetic coil transmitter stall test of claim 1, wherein, The control and measurement module (105) is provided with a pulse parameter feedback module, a voltage sensor (1053) and a current sensor (1054) for monitoring the voltage amplitude and current waveform, and a pressure sensor (1052) for monitoring the impact force waveform.

6. An impact mechanics loading method based on a stalling test of an electromagnetic coil transmitter, characterized by, The impact mechanics loading device suitable for the electromagnetic coil transmitter stall test in any one of claims 1-5 generates a transient pulse current by controlling the pulse power module (101) to charge and discharge through the upper computer (1051) to set the capacitor charging voltage, generates a pulse magnetic field through the coil (1021), and makes the conductor armature (1022) generate an axial impact electromagnetic force by inducing eddy current, the pulse width is adjusted by changing the capacitance value of the pulse capacitor (1011) and the inductance value of the coil (1021), the adjustment range is μs~ms, the amplitude is adjusted by changing the charging voltage value of the pulse capacitor (1011), the material and structure of the armature, and the axial relative position of the bottom surface of the conductor armature (1022) and the center line of the coil (1021); the position of the conductor armature (1022) is locked by rigid constraint to form stall, the impact electromagnetic force generated on the conductor armature (1022) is directly loaded to the sample (103) through the impact head (1023), and the test of the dynamic response, fatigue damage and aging accumulation of the material is realized; the specific steps are as follows: S1, according to the type of the impact force required for loading, determine whether to install a freewheeling diode (1014); according to the pulse width and amplitude of the required impact force, determine the corresponding pulse capacitor, coil inductance and charging voltage; S2 controls the pulse capacitor charging voltage to U 0; S3, after charging is completed, the upper computer (1051) is controlled to close the switch (1012) to conduct, and the pulse power module (101) discharges to the coil (1021) to generate a pulse current; S4, the conductor armature (1022) induces eddy current to generate an axial electromagnetic force, which is perpendicular to the surface of the sample (103) and closely contacts the sample (103), and the electromagnetic force is directly loaded to the sample (103) through the impact head (1023); S5, the impact force waveform is monitored through the pressure sensor (1052); S6, stop after single impact loading is completed; S7, repeat S1-S6, set the loading times and frequency to perform periodic repeated impact loading test.

7. An electronic device comprising a memory, a processor, and a computer program stored on the memory, wherein the computer program comprises instructions that, when executed by the processor, cause the electronic device to perform the method of any one of claims 1-6. The processor executes the computer program to realize the steps of the method of claim 6.

8. A computer readable storage medium having stored thereon computer programs / instructions, characterized in that, The computer program / instructions are executed by the processor to realize the steps of the method of claim 6.

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