Device for measuring shear modulus of material based on wedge interference principle

Abstract

The utility model discloses a device for measuring the shear modulus of a material based on a wedge interference principle, relates to the field of the shear modulus of the material, aims to solve the problem of high requirement on a detection environment in the prior art, and adopts the technical scheme that a Cabendish torsion balance structure and a wedge interference device are combined for use, so that the shear modulus of the material is measured. A linkage plate is arranged on a stress application frame of the Cabendish torsion balance, the linkage plate is connected with an upper glass sheet of the wedge interference device, a tiny torsion angle of a detected object is associated with a wedge change angle, and then the shear modulus of the detected object is associated with wedge interference fringe change. And the shear modulus of the detected object is obtained by observing the variation of the interference fringes. The measuring device is easy to operate, small in size and high in measuring method precision, the wedge interference method can be directly used for direct measurement of microcosmic quantity, the light path is short, the structure is compact, and the requirement for environment brightness is low.

Description

TECHNICAL FIELD

[0001] The utility model relates to material shear modulus detection technical field, concretely to a device of shear modulus of material based on wedge interference principle measurement. BACKGROUND

[0002] The shear modulus of material is an important mechanical parameter of solid material and is one of the design bases for engineering safety and durability. The existing shear modulus detection methods include torsion method, three-point overhanging beam bending method, dynamic method, optical lever method and strain gauge method. The torsion method clamps the detection material by a torsion tester, causes the detection material to twist after applying torsional force, and calculates the shear modulus by detecting the torsion angle with a micrometer. This method has poor detection accuracy.

[0003] Chinese patent CN117571506B discloses a shear modulus measurement device and method based on Michelson equal-thickness interference. The technical solution is to apply a horizontal tension to the torsion bar by adding weights, so that the torsion bar drives the measured material to twist. Two plane mirrors are arranged in the middle of the torsion bar. The sodium light lamp generates interference ripples. The Michelson interferometer detects the changes of the interference ripples during the twisting of the measured material, and then calculates the shear modulus of the measured material according to the change amount of the interference ripples.

[0004] Although this measurement method has high detection accuracy, it uses Michelson interference for detection. Michelson interference can measure length changes, but it relies more on the precise control of optical path difference, which is usually used to measure wavelength, refractive index or macroscopic displacement. The Michelson interference optical path is long and needs to propagate over a long distance after beam splitting. The observation of the fringes must be carried out in a dark environment, and the conversion between bright light and dark light during the test process requires a high detection environment. UTILITY MODEL CONTENT

[0005] The utility model solves the technical problem of overcoming the existing defects and provides a device and method for measuring the shear modulus of material based on wedge interference principle, which can effectively solve the problems in the background technology.

[0006] In order to achieve the above object, the utility model discloses a first device based on wedge interference principle measurement material's shear modulus first, the technical scheme is, including the bottom plate, the bottom plate has the fixing frame, the fixing frame has the first locking mechanism, still including the force frame, the force frame has the second locking mechanism and the torsion exerting mechanism, still be equipped with the linkage on the force frame, the bottom plate has the wedge interference device, the wedge interference device includes the upper glass sheet and lower glass sheet, both ends are flat, the upper glass sheet with the linkage is directly connected or indirectly connected, still including the light source, the light source with the wedge interference device position corresponding. The light source can form interference fringes on the wedge interference device, and the torsion exerting mechanism makes the detection object twist, and the force frame and the linkage can make the upper glass sheet rotate and form the wedge, thereby converting the torsion angle into the wedge angle, and further making the pitch of interference fringes change, the pitch change of interference fringes is obtained by calculating the wedge angle change, and the wedge interference can be carried out in the bright light environment, and the requirement of detection environment is low.

[0007] As a preferred technical scheme of the utility model, the first locking mechanism includes a first locking block, the second locking mechanism includes a second locking block, and a through hole and a locking screw hole communicated with the through hole are formed on the first locking block and the second locking block. A first bolt and a second bolt are respectively engaged in the two locking screw holes. The detection object can be fixed by the bolt and the locking block, and rapid installation and positioning can be realized.

[0008] As a preferred technical scheme of the utility model, the torsion exerting mechanism is a counterweight, and the counterweight is hung on one side of the force frame. The counterweight can apply a constant torsional force, and the torsional force can be stably adjusted.

[0009] As a preferred technical scheme of the utility model, a slide rail is arranged on the bottom plate, a sliding seat is slidably connected to the slide rail, a through positioning screw hole is formed in the sliding seat, a third bolt is engaged in the positioning screw hole, and the end face of the third bolt is connected with the slide rail. A supporting mechanism is connected to the sliding seat. The detection object can be supported to maintain its horizontal state.

[0010] As a preferred technical scheme of the utility model, a lifting platform is further arranged on the bottom plate, a reading microscope is arranged on the lifting platform, and the wedge interference device is arranged on the object stage of the reading microscope. The reading microscope can make the observation of the interference fringes more accurate, the height of the reading microscope can be adjusted by the lifting platform, and the height of the wedge interference device can be adjusted.

[0011] As an optimal technical scheme of the utility model, the eyepiece of the reading microscope is connected with a CCD light intensity sensor, and the CCD light intensity sensor is electrically connected with a computer. The CCD light intensity sensor can obtain the change of the fringes, and then the computer can obtain the change video of the interference fringes.

[0012] As an optimal technical scheme of the utility model, the eyepiece of the reading microscope is connected with a CCD light intensity sensor, and the CCD light intensity sensor is electrically connected with a computer. The CCD light intensity sensor can obtain the change of the fringes, and then the computer can obtain the change video of the interference fringes.

[0013] Compared with the prior art, the utility model has the beneficial effects that: the utility model combines the Cavendish torsion balance and the wedge interference device, associates the small torsion angle of the detection object with the wedge change angle, then associates the shear modulus of the detection object with the wedge interference fringe change, obtains the shear modulus of the detection object by observing the change amount of the interference fringes. The measuring device is simple to operate, small in size, high in measurement precision, and the wedge interference method can be directly used for direct measurement of micro-quantity, short in optical path and compact in structure, can directly observe in bright light environment, and has low requirements on the test environment. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 It is the device structure schematic view of the utility model Figure 1 ;

[0015] Figure 2 It is the device structure schematic view of the utility model Figure 2 ;

[0016] Figure 3 It is the device structure schematic view of the utility model Figure 3 ;

[0017] Figure 4 It is the wedge interference device structure schematic view of the utility model.

[0018] Figure 5 It is the connecting ring structure schematic view of the utility model.

[0019] In the diagram: 1. Base plate; 2. Fixing frame; 3. First locking block; 4. First bolt; 5. Detection object; 6. Force-applying frame; 601. Linkage plate; 7. Second locking block; 8. Second bolt; 9. Slide rail; 10. Slide seat; 11. Third bolt; 12. Support rod; 13. Support block; 14. Weight; 15. Sodium lamp; 16. Lifting platform; 17. Reading microscope; 18. Connecting ring; 1801. Upper ring; 1802. Lower ring; 1803. Expansion joint; 19. CCD light intensity sensor; 20. Wedge interference device; 201. Upper glass plate; 202. Lower glass plate; 203. Flexible connector. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0021] Example 1

[0022] like Figures 1 to 5 As shown, this utility model first discloses a device for measuring the shear modulus of a material based on the wedge interference principle. The technical solution adopted includes a base plate 1. In order to fix the object to be tested 5, a fixing frame 2 is set on the base plate 1. The fixing frame 2 has a first through hole. A first locking block 3 is set at the first through hole. The first locking block 3 has a first through hole and a first locking threaded hole. The first locking threaded hole and the first through hole are perpendicular. The object to be tested 5 is an aluminum alloy round tube, one end of which passes through the first through hole and the first through hole. A first locking threaded hole is engaged in the first locking threaded hole. A bolt 4 is used to fix the test object 5 by connecting its end face to the test object 5. The other end of the test object 5 is connected to a force-applying frame 6. A second through hole is provided on the force-applying frame 6, and a second locking block 7 is provided at the second through hole. The second locking block 7 has a second through hole and a second locking threaded hole. The second locking threaded hole is perpendicular to the second through hole. The free end of the test object 5 passes through the second through hole and the second through hole. A second bolt 8 is engaged in the second locking threaded hole. The end face of the second bolt 8 is connected to the test object 5, thus connecting the force-applying frame 6 to the test object 5.

[0023] In order to prevent the detection object 5 from bending or sinking under the action of gravity, the slide rail 9 is arranged on the bottom plate 1, the slide seat 10 is slidably connected on the slide rail 9, the positioning threaded hole is arranged on the top surface of the slide seat 10, the third bolt 11 is engaged in the positioning threaded hole, and the bottom surface of the third bolt 11 is in contact with the slide rail 9. The support rod 12 is connected to the slide seat 10, the supporting block 13 is connected to the support rod 12, and the detection object 5 is lifted by the supporting block 13.

[0024] In order to apply a torsional force to the detection object 5, a hook is arranged on one side of the force frame 6, a counterweight is hung on the hook, the counterweight is a weight 14, and a constant torsional force is applied through the weight 14.

[0025] In order to accurately detect the torsional angle of the detection object 5, the linkage plate 601 is arranged on the side, away from the weight 14, of the force frame 6, the torsional angle is detected by using the wedge interference principle, and the wedge interference device 20 is arranged on the linkage plate 601. Figure 4 As shown in the figure, the wedge interference device 20 comprises an upper glass sheet 201 and a lower glass sheet 202, one end of the upper glass sheet 201 and the lower glass sheet 202 is flush and connected through a flexible connecting piece 203, the length of the upper glass sheet 201 is greater than that of the lower glass sheet 202, in order to generate interference fringes on the wedge interference device 20, a light source is arranged on the bottom plate 1, the light source is a sodium light lamp 15 with a wavelength of 589 nm, in order to clearly observe the change of the interference fringes, the wedge interference device 20 is arranged on the reading microscope 17, the stage of the reading microscope 17 has a pressing piece, and the wedge interference device 20 is pressed by the pressing piece. In order to make the upper glass sheet 201 in contact with the linkage plate 601, the lifting table 16 is arranged between the bottom plate 1 and the reading microscope 17. In order to facilitate subsequent calculation, the effective length of the upper glass sheet 201 is controlled to be equal to the length of the force arm of the force frame 6, at this time, the change of the angle of the wedge is equal to the angle of rotation of the force frame 6, that is, the change of the angle of the wedge is equal to the torsional angle of the detection object 5.

[0026] In order to further facilitate reading and calculation of the interference fringes, the connecting ring 18 is sleeved on the eyepiece of the reading microscope 17, as shown in the figure. Figure 5 As shown in the figure, the connecting ring 18 comprises an upper ring 1801 and a lower ring 1802, the lower ring 1802 is connected with the eyepiece, in order to facilitate sleeving, the expansion joint 1803 is arranged on the side wall of the lower ring 1802, the upper ring 1801 is in contact with the lower ring 1802, the CCD light intensity sensor 19 is inserted into the upper ring 1801, and the CCD light intensity sensor 19 is electrically connected with the computer.

[0027] The utility model discloses further disclose a kind of material shear modulus measurement method based on above-mentioned measuring device, the technical scheme adopted is as follows:

[0028] Step 1, the diameter D of detection object 5 is measured, when measuring diameter, average value is taken after detection in six different positions;

[0029] Step 2, one end of the detection object 5 is fixed on the fixed frame 2 through the first locking mechanism, and the other end is fixed on the force frame 6 through the second locking mechanism. When fixing, the distance between the force frame 6 and the fixed frame 2 is kept at 250mm (i.e. the effective torsion length L), and the force frame 6 is ensured to be horizontal through the level. After moving the sliding seat 10 to the appropriate position, supporting the detection object 5 through the supporting block 13 to maintain the horizontal (verified by the level), and screwing the third bolt 11, the third bolt 11 is tightly positioned against the sliding rail 9 to the sliding seat 10;

[0030] Step 3, place the wedge interference device 20, and place the wedge interference device 20 so that the end of the soft connecting piece 203 of the wedge interference device 20 is away from the linkage plate 601. After pressing the wedge interference device 20 on the object table using the pressing sheet, adjust the height of the lifting table 16 so that the bottom surface of the upper glass sheet 201 is just connected with the top of the linkage plate 601. The effective length of the upper glass sheet 201 and the length of the force arm of the force frame 6 are both kept at 150mm.

[0031] Step 4, after the sodium light lamp 15 is turned on and preheated for 10 minutes to reach the stable state, the height of the sodium light lamp 15 is adjusted so that the light outlet is directly opposite the half-reflective half-transmissive lens of the reading microscope 17. The half-reflective half-transmissive lens is adjusted so that the stripe contrast in the computer display screen reaches the highest. At this time, the stripes on the wedge interference device 20 are observed, and the stripe spacing is obtained through image processing, and the initial stripe spacing D1 is obtained.

[0032] Step 5, the force frame 6 is subjected to a torsion force through the hanging weight 14, so that the end surface of the detection object 5 is subjected to an external moment to be twisted. The force frame 6 drives the upper glass sheet 201 to rotate, causing the glass sheet to produce a small angle change.

[0033] Step 6, the interference stripe spacing change is obtained through image processing, the changed stripe spacing D2 is obtained, and the wedge angle change amount is calculated through the change angle calculation formula:

[0034]

[0035] Wherein, λ is the wavelength of the incident light, D1 is the initial stripe spacing, and D2 is the changed stripe spacing.

[0036] Step 7, since the effective length of the upper glass sheet 201 is equal to the length of the force arm of the force frame 6, at this time

[0037]

[0038] The shear modulus is calculated through the shear modulus calculation formula:

[0039]

[0040] Wherein, T is the external force torque; L is the effective torsion length of the round rod; I is the polar moment of inertia of the cross section; is the total torsion angle of the end face; D is the diameter of the detection object 5.

[0041] Comparative Example 1: Chinese Patent CN117571506B, a shear modulus measuring device and measuring method based on Michelson equal thickness interference.

[0042] According to the disclosure text of Chinese Patent CN117571506B, the relative error of the shear modulus measured by the measuring method disclosed in Comparative Example 1 is 0.39%.

[0043] According to the measuring method disclosed in Example 1, the shear modulus of the detection object 5 was measured using a device for measuring the shear modulus of the material based on the wedge interference principle:

[0044] In a laboratory environment of 22℃ and 45% humidity, a 6061 type cylindrical aluminum alloy rod was used as the detection object 5, and the measuring device parameters were as follows:

[0045] Name Length of force frame / m Length of force arm / m Length of material to be tested / m Polar moment of inertia of cross section / m Size 0.3 0.15 0.25 4.0192*10 -10 ]]>

[0046] The diameter was measured from six points on the left, middle and right of the detection object 5, and the average value was taken, as follows:

[0047]

[0048] In each measurement, first measure and record the fringe spacing without adding weights; after adding a certain amount of weights, measure and record the resulting fringe spacing, calculate the corresponding wedge angle change, and use the formula to calculate the shear modulus of the material to be measured.

[0049] The shear modulus G was measured using 10 groups of weights from 10g to 100g, and the results were as follows:

[0050]

[0051]

[0052] Given that the standard value of the shear modulus G of 6061 type aluminum alloy is 25.9Gpa, the relative error of the measuring device and measuring method of Example 1 is calculated as follows:

[0053]

[0054] From the above comparison results, it can be seen that the present application has very high precision, and can ensure a relative error of less than 1% under the premise of weakening the requirements for the detection environment, and the entire device is more compact, making it more convenient for detection work.

[0055] The circuit and mechanical connection involved in the utility model are the common means adopted by the person skilled in the art, and can be obtained by limited tests, which belong to the common knowledge.

[0056] The components not described in detail in the present application are prior art.

[0057] Although the embodiments of the utility model have been shown and described, it can be understood by those of ordinary skill in the art that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and spirits of the utility model, and the scope of the utility model is defined by the appended claims and their equivalents.

Claims

1. An apparatus for measuring the shear modulus of a material based on the wedge interference principle, characterized by: The utility model relates to a kind of glass cutting machine, including bottom plate (1), the fixed frame (2) on the bottom plate (1), the first locking mechanism on the fixed frame (2), still including force frame (6), the second locking mechanism and torsion exerting mechanism on the force frame (6), linkage is further equipped on the force frame (6);The bottom plate (1) has wedge interference device (20), the wedge interference device (20) includes upper glass sheet (201) and lower glass sheet (202), both ends are flat, the upper glass sheet (201) is directly connected with linkage or indirectly connected;It further includes light source, the light source is position corresponding with the wedge interference device (20).

2. The apparatus for measuring the shear modulus of a material based on the wedge interference principle according to claim 1, characterized in that: The first locking mechanism includes first locking block (3), the second locking mechanism includes second locking block (7), the first locking block (3) and the second locking block (7) are all set with perforation and locking screw hole being communicated with the perforation, and first bolt (4) and second bolt (8) are engaged in two locking screw holes respectively.

3. The apparatus for measuring the shear modulus of a material based on the wedge interference principle according to claim 1, characterized in that: The torsion exerting mechanism is counterweight, and the counterweight is hung on one side of the force frame (6).

4. The apparatus for measuring the shear modulus of a material based on the principle of the wedge interference according to claim 1, characterized in that: The bottom plate (1) has slide rail (9), the slide rail (9) is slidably connected with slide base (10), the slide base (10) is set with the through positioning screw hole, the third bolt (11) is engaged in the positioning screw hole, and the end surface of the third bolt (11) is connected with the slide rail (9);Support mechanism is connected on the slide base (10).

5. The apparatus for measuring the shear modulus of a material based on the wedge interference principle according to claim 1, wherein: The bottom plate (1) also has lifting platform (16), the reading microscope (17) is on the lifting platform (16), and the wedge interference device (20) is on the object table of the reading microscope (17).

6. The apparatus for measuring the shear modulus of a material based on the wedge interference principle according to claim 5, characterized in that: The eyepiece of the reading microscope (17) is connected with CCD light intensity sensor (19), and the CCD light intensity sensor (19) is electrically connected with computer.

7. The apparatus for measuring the shear modulus of a material based on the principle of the wedge interference according to claim 6, characterized in that: The eyepiece of the reading microscope (17) is connected with the CCD light intensity sensor (19) by connecting ring (18), and the connecting ring (18) includes upper ring (1801) and lower ring (1802), the upper ring (1801) is connected with the lower ring (1802), the lower ring (1802) is connected with the eyepiece of the reading microscope (17), and the upper ring (1801) is connected with the CCD light intensity sensor (19).

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