Magnetic induced strain measurement device suitable for experiment teaching

Abstract

The utility model discloses a magnetic-induced strain measuring device suitable for experiment teaching, relates to the technical field of test equipment, and solves the problem that an existing magnetic-induced strain measuring device cannot enable alloy to completely recover deformation. An alloy sample is vertically placed in the middle of an electromagnet through a non-magnetic clamp; the electromagnet is connected with the adjustable direct-current stabilized power supply; a laser displacement sensor is arranged right above the alloy sample, and the laser displacement sensor, the controller and the power supply are connected in sequence; the controller is also connected with the data processor; the strain recovery device comprises a dial indicator and a base, the dial indicator is arranged on the base, a sample groove is formed in the base, the alloy sample is placed in the sample groove in the base, and the alloy sample is recovered through the dial indicator. According to the utility model, the original size of the sample is completely recovered by using the pressure, and the magnetic-induced strain of the sample can be intuitively expressed from the dial indicator, so that the magnetic-induced strain test experimental teaching platform can be used as a magnetic-induced strain test experimental teaching platform.

Description

Technical Field

[0001] The utility model relates to the technical field of testing equipment, in particular to a magnetic induced strain measuring device suitable for experimental teaching. Background Art

[0002] Ferromagnetic shape memory alloys, represented by Ni-Mn-based alloys, can reorient martensitic twin variants under the action of an external magnetic field, thereby generating large reversible strain, namely magnetic field induced strain (MFIS). This achieves a combination of large output strain and high response frequency, and has broad application prospects in key fields such as aerospace and robotics, and is expected to become a new generation of driving and sensing materials.

[0003] Obviously, the precise measurement of magnetically induced strain is of great significance for its engineering application. At present, relevant patents have proposed a test platform for magnetically induced strain. The Chinese patent with publication number CN106646293A discloses "A device and method for high-precision, large-scale, non-contact measurement of magnetostrictive strain", which calculates the sample strain through the change of the reflection loop generated by the laser emitted by the laser displacement sensor on the sample surface, realizes non-contact measurement, avoids the problem of traditional strain gauge method hindering sample deformation, and improves measurement accuracy. The Chinese patent with publication number CN208297419U discloses "A cyclic magnetically induced strain test platform", which also uses a laser rangefinder to accurately measure the dimensional changes of the sample, and proposes the use of alternating electromagnets to change the size and direction of the magnetic field to achieve cyclic measurement of magnetically induced strain.

[0004] However, we know that due to factors such as internal friction, residual stress, and hysteresis effects generated by the twin rearrangement process, the alloy cannot usually be completely restored to its original shape by changing the direction of the magnetic field. That is, there will be a certain amount of strain loss in each measurement. This method is not well suited for cyclic measurements of magnetically induced strain. Utility Model Content

[0005] To address the aforementioned issue of existing magnetically induced strain measurement devices failing to fully restore alloy deformation, this utility model proposes a magnetically induced strain measurement device suitable for experimental teaching. This device utilizes pressure to fully restore a sample to its original dimensions. The magnetically induced strain of the sample can be visually displayed on a dial gauge, providing strong evidence of the strain measured by the laser displacement sensor. This device can serve as a platform for magnetically induced strain testing in experimental teaching, possessing significant practical value.

[0006] The utility model proposes a magnetic induced strain measuring device suitable for experimental teaching, which specifically comprises an electromagnet, an adjustable DC regulated power supply, a laser displacement sensor, a controller, a power supply, a data processor, a fixture and a strain recovery device. The alloy sample is vertically placed in the middle of the electromagnet through the fixture; the electromagnet is connected to the adjustable DC regulated power supply; a laser displacement sensor is arranged directly above the alloy sample, and the laser displacement sensor, the controller and the power supply are connected in sequence; the controller is also connected to the data processor; the strain recovery device comprises a dial indicator and a base, the dial indicator is arranged on the base, a sample slot is arranged in the base, the alloy sample that has undergone magnetic induced strain is placed in the sample slot, and the alloy sample is restored to its original state through the dial indicator; and the fixture is a non-magnetic fixture.

[0007] Furthermore, the fixture includes an aluminum fixture and a brass block, and the aluminum fixture is arranged on the brass block.

[0008] Furthermore, the invention further comprises a gaussmeter, which is arranged on one side of the electromagnet.

[0009] Furthermore, the gaussmeter is powered by a power supply.

[0010] Furthermore, it also includes a camera, which is facing the alloy sample to record the deformation process of the alloy sample.

[0011] Furthermore, the adjustable DC regulated power supply is powered by a power supply.

[0012] Furthermore, the power supply is powered by a power supply.

[0013] The beneficial effects of the magnetic induced strain measurement device suitable for experimental teaching described in the utility model are:

[0014] (1) The magnetic induced strain measuring device suitable for experimental teaching described in the utility model overcomes the problem that the existing magnetic induced strain measuring device cannot completely restore the deformation of the alloy. The strain recovery device uses pressure to completely restore the sample to its original size, and the magnetic induced strain of the sample can be intuitively displayed on the dial. It is a powerful proof of the strain obtained by the laser displacement sensor and can be used as a magnetic induced strain test experimental teaching platform with important practical value.

[0015] (2) The magnetically induced strain measurement device described in the present invention is suitable for experimental teaching. It uses an ultra-high-speed / high-precision CMOS laser displacement sensor to achieve precise measurement of micron-level strain with a measurement accuracy of ±1.2μm; and has a fast response frequency of up to 50kHz. A camera is used to record the sample deformation process during measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention.

[0017] In the attached figure:

[0018] Figure 1 This is a structural diagram of a magnetic induced strain measuring device suitable for experimental teaching described in the utility model;

[0019] Figure 2 This is a structural diagram of a strain recovery device of a magnetically induced strain measuring device suitable for experimental teaching according to the utility model;

[0020] Figure 3 This is a structural diagram of a Gaussmeter of a magnetically induced strain measuring device suitable for experimental teaching according to the utility model;

[0021] Figure 4 This is a structural diagram of a camera of a magnetically induced strain measuring device suitable for experimental teaching according to the utility model;

[0022] Figure 5 This is a magnetic induced strain curve of an alloy sample obtained by the first test of a magnetic induced strain measuring device suitable for experimental teaching described in the utility model;

[0023] Figure 6 This is a magnetic induced strain curve of the alloy sample of the second test of the magnetic induced strain measuring device suitable for experimental teaching described in the utility model;

[0024] Figure 7 This is the magnetic induced strain curve of the alloy sample of the third test of the magnetic induced strain measuring device suitable for experimental teaching described in the utility model;

[0025] Among them: 1-alloy sample, 2-electromagnet, 3-adjustable DC regulated power supply, 4-laser displacement sensor, 5-controller, 6-power supply, 7-data processor, 8-Gaussmeter, 9-camera, 10-strain recovery device, 11-power supply, 12-aluminum fixture, 13-brass block. DETAILED DESCRIPTION

[0026] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0027] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0028] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0029] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0030] Specific implementation method 1: See Figure 1-Figure 7 The present embodiment is described in detail. The magnetically induced strain measurement device suitable for experimental teaching described in this embodiment specifically includes an electromagnet 2, an adjustable DC regulated power supply 3, a laser displacement sensor 4, a controller 5, a power supply 6, a data processor 7, a fixture and a strain recovery device 10. The alloy sample 1 is a single crystal nickel-manganese-gallium alloy, a rectangular thin sheet with a size of 1mm×2.75mm×20mm. When the alloy sample 1 is installed, the thickness direction of the sample (thickness is 1mm) is placed vertically in the fixture along the direction perpendicular to the magnetic field. The transformation temperature of the alloy sample 1 from martensite to austenite is 55°C, which meets the requirement that the sample is in a martensitic state under room temperature testing.

[0031] Electromagnet 2 is connected to an adjustable DC regulated power supply 3 via copper wire. When powered, it generates a horizontal magnetic field. Adjusting the knobs on the left and right sides of electromagnet 2 controls the magnetic field gap, and thus the magnitude of the field. The magnetic field gap can be adjusted from 0 to 20 mm. The magnetic field can reach a maximum of 2 Tesla. One end of the adjustable DC regulated power supply 3 is connected to electromagnet 2, and the other end is connected to power supply 11. The voltage is continuously adjustable from 0 to 32 V, and the output current is 0 to 10.0 A. It provides overvoltage protection (OVP), overcurrent protection (OCP), and overtemperature protection (OTP), which can be set as needed.

[0032] A laser displacement sensor 4 is provided directly above the alloy sample 1; the laser displacement sensor 4 is an ultra-high-speed / high-precision CMOS laser displacement sensor with an acquisition frequency of up to 50kHz and a measurement accuracy of ±1.2μm. It is fixed above the sample using a magnetic bracket, which is fixed on a desktop. The laser displacement sensor 4 detects the strain of the alloy sample 1; the laser displacement sensor 4, the controller 5, and the power supply 6 are connected in sequence; the controller 5 is connected to the laser sensing head of the laser displacement sensor 4 via a cable and is placed away from the magnetic field environment; the power supply 6 is connected to the controller 5 via a copper wire, and the power supply 6 inputs an AC voltage of 100V to 240V, an input frequency of 50 / 60Hz, an input current of 2.2A, and outputs a stable DC voltage of 24V and 6.5A; the controller 5 is also connected to a data processor 7, which collects, stores, and reads data through the PC-side configuration software LK-Navigator2, and uses Origin for data processing to draw the sample's magnetically induced strain-time curve;

[0033] The strain recovery device 10 includes a dial indicator and a base. The dial indicator is set on the base. A sample slot is set in the base. The alloy sample 1 that has magnetically induced strain is placed in the sample slot. By pressing the button on the dial indicator, the sample is completely restored to its original size by pressure. The dial indicator can intuitively display the magnetically induced strain of the sample and the process of the sample recovering its deformation after pressure is applied.

[0034] The fixture is a non-magnetic fixture to avoid affecting the magnetic field generated by the electromagnet 2 and causing displacement changes.

[0035] The fixture includes an aluminum fixture 12 and a brass block 13 , and the aluminum fixture 12 is clamped in the brass block 13 .

[0036] The device further comprises a gaussmeter 8, which is arranged on one side of the electromagnet 2. A Hall probe connected to the gaussmeter 8 is placed in the magnetic field gap to detect the magnitude of the magnetic field generated by the electromagnet 2. The gaussmeter 8 is powered by a power supply 11.

[0037] The device further comprises a camera 9 , which faces the alloy sample 1 and records the deformation process of the alloy sample 1 .

[0038] The adjustable DC regulated power supply 3 is powered by a power supply 11 .

[0039] The power supply 6 is powered by a power source 11 .

[0040] The power supply 11 is a 220V AC power supply.

[0041] The specific measurement process of the magnetic induced strain measurement device suitable for experimental teaching described in this utility model is explained as follows:

[0042] like Figure 1 As shown, disconnect the power cord and connect the devices. Once the connections are complete and the wiring is correct, begin the experiment. Place the sample in the strain recovery device 10 and gently place the dial indicator's measuring pointer on the sample surface, ensuring the pointer is stable and in good contact with the sample. Manually rotate the outer dial on the dial indicator until the pointer is aligned with zero. After zeroing, secure the dial to prevent it from shifting during measurement.

[0043] Turn on the switch on the back of adjustable DC regulated power supply 3 and adjust the current and voltage knobs to 32V and 10A (clockwise rotation increases the output voltage and current; counterclockwise rotation decreases them). Press and hold the current adjustment knob to lock the current; the lock indicator will illuminate, putting the power supply in CC steady-state operation. Press the OVP overvoltage protection button. Then, press the ON / OFF button. The indicator will illuminate, indicating the output function is enabled. At this point, electromagnet 2 is energized and operating.

[0044] Turn on Gaussmeter 8 and reset the reading to zero. Then place the Hall probe of Gaussmeter 8 in the magnetic field gap. The magnetic field strength is displayed on the LED screen. Adjust the knobs on the left and right sides of electromagnet 2 to reach a magnetic field strength of 1.38T. Remove the Hall probe and turn off adjustable DC regulated power supply 3.

[0045] Place alloy sample 1 in aluminum fixture 12 and within the magnetic field gap, with the sample centered at the center of the magnetic field. Connect power supply 6 to a 220V AC power source. All settings and commands are sent to controller 5 via the computer-side configuration software, LK-Navigator 2. Laser displacement sensor 4 outputs a laser beam that strikes the surface of alloy sample 1. First, observe the waveform of the received light in the software. Generally, a sharp peak in the middle is optimal, and the indicator light above laser displacement sensor 4 should illuminate green.

[0046] After completing the above debugging steps, disconnect and reconnect the power supply to officially begin testing. In the LK-Navigator2 software, set the acquisition frequency to 5 kHz and send the set value to the controller. Then, reset the measured value in the measurement display to zero. Open the data storage module and set the data storage capacity to 150,000 (i.e., the acquisition time is 30 seconds).

[0047] Click "Save Start" to start data collection. Laser displacement sensor 4 then begins collecting data. Then, press the ON / OFF button on adjustable DC regulated power supply 3 to output a constant current. Electromagnet 2 is momentarily energized to generate a magnetic field, causing alloy sample 1 to deform until data point collection is complete. Simultaneously, camera 9 captures and records the deformation process of alloy sample 1 in real time.

[0048] After the acquisition is complete, press the ON / OFF button again to turn off the magnetic field. Remove alloy sample 1 and place it in the strain recovery device 10. Gently place the measuring pointer on the sample surface. The dial indicator pointer rotates one circle clockwise, indicating that alloy sample 1 has undergone a height displacement of 1.23 mm.

[0049] Open the stored data in the LK-Navigator2 software and read out the displacement change. The laser displacement sensor records a displacement change of 1.233 mm, which is consistent with the reading on the dial indicator. Finally, gently press the button on the dial indicator until the pointer rotates counterclockwise to zero, and the sample completely returns to its original size. Repeat these steps three times.

[0050] The data was imported into the Origin plotting software. Based on the 20mm height of alloy sample 1, the displacement (unit: mm) was converted to strain. The number of collected data points was converted to time (unit: s). A strain-time curve for the sample under magnetic field drive was plotted, with time as the horizontal axis and strain as the vertical axis. The response time of the sample to magnetic field-driven strain was further determined based on the variation range. The endpoint coordinates of the variation range (t1, x1) and (t2, x2) were read from the curve; the response time Δt = t2 - t1, and the response frequency f = 1 / Δt = 1 / (t2 - t1), both in Hz. Figure 5-Figure 7 The magnetic induced strain curves under three tests are shown in Table 1. The sample size is 1mm×2.75mm×20mm. In the first test, the magnetic induced strain is 6.1%, the response time is 0.134s, and the response frequency is 7.4Hz. In the second test, the magnetic induced strain is 6.3%, the response time is 0.140s, and the response frequency is 7.1Hz. In the third test, the magnetic induced strain is 6.2%, the response time is 0.137s, and the response frequency is 7.3Hz. The test results are shown in Table 1.

[0051] Table 1

[0052]

[0053]

[0054] Summarizing the above implementation cases, the magnetically induced strain measurement device suitable for experimental teaching described in the utility model overcomes the problem that existing magnetically induced strain measurement devices cannot completely restore the deformation of the alloy. The strain recovery device 10 uses pressure to completely restore the sample to its original size, and the magnetically induced strain of the sample can be intuitively displayed on the dial gauge, which is a strong proof of the strain obtained by the laser displacement sensor 4. It can be used as a magnetically induced strain test experimental teaching platform and has important practical value. The magnetically induced strain measurement device suitable for experimental teaching described in the utility model uses an ultra-high-speed / high-precision CMOS laser displacement sensor to achieve precise measurement of micron-level strain with a measurement accuracy of ±1.2μm; and has a fast response frequency of up to 50kHz; while measuring, a camera 9 is used to record the sample deformation process.

[0055] The specific embodiments described above further illustrate the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above description is merely a specific embodiment of the present invention and is not intended to limit the present invention. Reasonable combinations of the features described in the above embodiments are also possible. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A magnetically induced strain measurement device suitable for experimental teaching, characterized by: The invention comprises an electromagnet (2), an adjustable DC voltage-stabilized power supply (3), a laser displacement sensor (4), a controller (5), a power supply (6), a data processor (7), a fixture and a strain recovery device (10), wherein the alloy sample (1) is vertically placed in the middle of the electromagnet (2) through the fixture; the electromagnet (2) is connected to the adjustable DC voltage-stabilized power supply (3); a laser displacement sensor (4) is arranged directly above the alloy sample (1); the laser displacement sensor (4), the controller (5) and the power supply (6) are connected in sequence; and the controller (5) is also connected to the data processor (7); The strain recovery device (10) comprises a dial indicator and a base, wherein the dial indicator is arranged on the base, and a sample slot is arranged in the base. The alloy sample (1) that has undergone magnetically induced strain is placed in the sample slot, and the alloy sample (1) is restored to its original state by the dial indicator; The clamp is non-magnetic.

2. The magnetically induced strain measuring device suitable for experimental teaching according to claim 1, characterized in that: The clamp comprises an aluminum clamp (12) and a brass block (13), wherein the aluminum clamp (12) is arranged on the brass block (13).

3. The magnetically induced strain measuring device suitable for experimental teaching according to claim 1, characterized in that: The device further comprises a gauss meter (8), which is arranged on one side of the electromagnet (2).

4. The magnetically induced strain measuring device suitable for experimental teaching according to claim 3 is characterized in that: The gaussmeter (8) is powered by a power supply (11).

5. The magnetically induced strain measuring device suitable for experimental teaching according to claim 1, characterized in that: The invention also includes a camera (9), which faces the alloy sample (1) and records the deformation process of the alloy sample (1).

6. The magnetically induced strain measuring device suitable for experimental teaching according to claim 1, characterized in that: The adjustable DC regulated power supply (3) is powered by a power supply (11).

7. The magnetically induced strain measuring device suitable for experimental teaching according to claim 1, characterized in that: The power supply (6) is powered by a power source (11).

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