Device for measuring shear modulus of regular solid material based on optical detection technology

Abstract

The utility model discloses a device for measuring the shear modulus of a regular solid material based on an optical detection technology. The device comprises a light source, a pressure gauge, a wedge interference plate and a reading microscope, the pressure gauge is placed on an objective table of the reading microscope, one end of the wedge interference plate is lapped on a workbench of the pressure gauge, and the light source is located right opposite to the reading microscope; the pressure gauge applies pressure to an object to be measured to deform the object, a reflective mirror in the reading microscope reflects light rays through a light source, the light rays pass through the wedge interference plate and an objective lens and an eyepiece in the reading microscope, and the change of aperture stripe displacement is read by the reading microscope. According to the utility model, the problems that the existing traditional instrument for detecting the shear modulus is low in measurement accuracy, limited in material measurement types and the like are solved, and the cost of high-precision test equipment is reduced.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the field of measurement based on optical detection technology, especially relates to a device for measuring the shear modulus of regular solid materials based on optical detection technology. BACKGROUND

[0002] Optical detection is a method of non-contact, high-precision and high-efficiency measurement and detection of measured objects using optical principles and techniques. It is based on the basic principles of light propagation, scattering, reflection and refraction, and by collecting, processing and analyzing the light signal, the shape, size, surface roughness and defects of the measured object are obtained. Shear modulus is a physical quantity representing the ability of a material to resist shear strain, and is one of the mechanical properties of materials.

[0003] Shear modulus is an important parameter in material mechanics, and is of great significance for understanding and predicting the behavior of materials under shear stress. In engineering applications, accurate measurement and evaluation of the shear modulus of materials are crucial to ensure the safety and reliability of structures. The existing shear modulus technology has limitations in measurement error and testing method. The instrument measurement accuracy is not high, and the measurement method is complex. Secondly, high-precision shear test equipment usually has high cost, and needs to be maintained and calibrated regularly to ensure its accuracy and reliability, which increases the cost and time of measurement. SUMMARY

[0004] The utility model aims at providing a kind of device for measuring the shear modulus of regular solid materials based on optical detection technology, the device has the advantages such as structure is convenient for measurement and observation, phenomenon is stable and data processing result is more accurate, to solve the technical problems of the instrument measurement precision not being high and the limitation of material measurement type of existing traditional detection shear modulus.

[0005] To solve the above technical problems, the specific technical scheme of the utility model is as follows:

[0006] A kind of device for measuring the shear modulus of regular solid materials based on optical detection technology, including light source, pressure gauge, wedge interference plate, reading microscope;Pressure gauge is placed on the stage of reading microscope, wedge interference plate one end is placed on the workbench of pressure gauge, light source is located in the opposite side of reading microscope;Pressure gauge exerts pressure on the measured object to make it deform, the reflecting mirror in reading microscope reflects light through light source, makes light pass through wedge interference plate and objective lens and ocular lens in reading microscope, the change of aperture fringe displacement is read out using reading microscope.

[0007] Further, the wedge interference plate is composed of two glass plates and a metal plate, and one end of the two glass plates is fixed together under the action of the metal plate.

[0008] Further, the two glass plates have a thickness of 2-3 mm, a width of 5-6 cm, and a length of 65-80 cm.

[0009] Further, the pressure gauge comprises a load frame, an actuator, a controller connection port, a limiting device and a pressure sensor.

[0010] The load frame comprises a column, an upper beam, a movable beam, a workbench and a ball screw; the column is vertically installed on both sides of the workbench, and the upper end is fixedly connected with the upper beam, and the lower end is fixedly connected with the workbench, thereby forming a rigid frame; the ball screw is installed on both sides of the frame, and the upper end is connected with the upper beam 14 bearing, and the lower end is connected with the pulley at both ends of the lower part of the frame table, thereby forming a stable portal structure for supporting and guiding the movement of the movable beam; the movable beam is movably connected with the nut part of the ball screw at both ends; the transmission system of the movable beam is connected with the movable beam by using the rolling screw, and the up-down movement of the movable beam is realized by driving the motor; the motor is embedded in the bottom of the load frame.

[0011] The actuator is fixed on the movable beam, and the pressure applied to the object is adjusted according to the instruction of the controller until the set pressure value is reached.

[0012] The controller is embedded in the upper beam, receives the instruction and controls each component of the testing machine.

[0013] The connection port is fixed on the upper beam, so that the pressure gauge is connected with the computer.

[0014] The limiting device is embedded below the column, and prevents the movable beam from exceeding the running range.

[0015] The pressure sensor is embedded in the upper beam, and is used for detecting the actual pressure value applied to the object.

[0016] The device for measuring the shear modulus of regular solid material based on the optical detection technology has the following advantages: the device is designed by using the optical detection technology and the light interference principle, has the advantages of convenient measurement and observation, stable phenomenon and relatively accurate data processing result, solves the problems of low measurement accuracy of the existing traditional shear modulus detection instrument, limitation of material measurement types and the like, and reduces the cost problem of high-precision test equipment. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 The device for measuring the shear modulus of regular solid material based on the optical detection technology is designed as a block diagram structure schematic view.

[0018] Figure 2 The shear modulus measurement device structure schematic view is designed as a block diagram structure schematic view.

[0019] Figure 3 The pressure gauge is a schematic view of the utility model;

[0020] Figure 4 The small deformation schematic view is generated by the stretching of the object to be measured of the utility model;

[0021] Figure 5 The light path diagram at the optical interferometer of the utility model;

[0022] Figure 6 The wedge interference plate composition and principle schematic view of the utility model. DETAILED DESCRIPTION

[0023] In order to better understand the purpose, structure and function of the utility model, the device for measuring the shear modulus of regular solid material based on optical detection technology will be further described in detail below in combination with the drawings.

[0024] A device for measuring the shear modulus of regular solid material based on optical detection technology, as shown in Figure 1 The device mainly comprises a light source 7, a pressure gauge 3, a wedge interference plate and a reading microscope; the pressure gauge 3 is placed on the object table of the reading microscope, one end of the wedge interference plate is placed on the workbench of the pressure gauge 3, and the light source 7 is located opposite the reading microscope.

[0025] The reading microscope comprises a coarse focusing screw 1, a fixed mirror 4, an eyepiece 6, a fine focusing screw 8 and an objective lens 9.

[0026] The light source 7 further comprises an adjusting knob 11, which is used for adjusting the height of the light source 7 so that the light can irradiate the mirror 4.

[0027] The wedge interference plate is composed of two glass plates 10 and a metal plate 5, wherein the two glass plates have a thickness of 2-3 mm, a width of 5-6 cm and a length of 65-80 cm, and the other end of the two glass plates 10 is fixed together under the action of the metal plate 5.

[0028] The pressure gauge adopts a similar model WDW-1E / 2E / 5E electronic universal testing machine, which mainly comprises a load frame, a limiting device 17, a pressure sensor, a controller, an actuator 12 and a wiring port 2.

[0029] The main part is the load frame and the actuator 12, which is usually composed of a column 13, an upper beam 14, a movable beam 15, a workbench 16 and a ball screw, the column 13 is vertically installed on both sides of the workbench, the upper end is fixedly connected with the upper beam, and the lower end is fixedly connected with the workbench, thereby forming a rigid frame, the ball screw is installed in the frame, the upper end is connected with the upper beam 14 through a bearing, and the lower end is connected with the frame table through a pulley or other ways, thereby forming a stable portal structure for supporting and guiding the movement of the movable beam 15, and the transmission system is driven by a motor (which is embedded in the bottom of the frame and connected with the movable beam through the ball screw), so that the movable beam moves up and down;

[0030] The actuator 12 is fixed on the movable beam 15, and according to the instruction of the controller, the pressure applied to the object is adjusted until the set pressure value is reached;

[0031] In the secondary part, the wiring port 2 is fixed on the upper beam, so that the pressure gauge can be connected with the computer;

[0032] The limiting device 17 is embedded below the column to prevent the movable beam from exceeding the running range;

[0033] The pressure sensor is embedded in the upper beam 14, which is used for detecting the actual pressure value applied to the object;

[0034] The controller is embedded in the upper beam 14, which receives instructions and controls each component of the testing machine.

[0035] The utility model device schematic view is as shown in Figure 2 The utility model device schematic view is as shown in

[0036] First, one end of the two glass plates 10 is fixed together with the metal plate 5, and the other end is placed on the workbench 16 of the pressure gauge 3. Turn on the light source 7, adjust the fixed mirror 4, so that a bright field of view appears in the ocular lens 6, then adjust the coarse focusing screw 1 and the fine focusing screw 8, and detect whether the aperture fringe can be clearly appeared in the ocular lens 6. The wiring port 2 is fixed on the upper beam 15 of the pressure gauge 3, the pressure value is input on the computer connected with the pressure gauge 3 through the wiring port 2, then the actuator 12 in the pressure gauge 3 is driven by the movable beam 15 to apply pressure to the measured object, so that the measured object is slightly deformed, thereby changing the displacement of the aperture fringe, and finally the shear modulus is calculated through the formula.

[0037] The derivation process of the formula is introduced as follows. The shear measuring instrument mainly relies on the shear Hook's law of the tension meter to measure the tension and the optical interference principle to measure the wavelength, so the derivation of the formula involves two parts.

[0038] After the instrument is installed according to the above process, the sample to be measured is placed in the pressure gauge 3. The sample to be measured will be shortened in the height direction under the action of external force, that is, deformation occurs. Assuming that the shear surface area of the sample to be measured is A and the height is H. A pressure F is applied in the height direction, so that the sample to be measured is shortened , the ratio is the force per unit cross section, called stress; the ratio is the relative shortening of the object, called strain, which represents the size of the deformation of the object.

[0039] According to the basic formula of shear modulus in Hook's law,

[0040] (1)

[0041] In the formula, G represents the shear modulus, represents the shear stress, represents the shear strain, and from the force and area, it can also be represented as

[0042] (2)

[0043] Since the regular solid is used as the material, and can be measured by a general measuring tool, and F can be displayed on the computer connected with the pressure gauge in the experiment.

[0044] The shear modulus of the sample to be measured can be measured by the optical interference principle and the pressure gauge system. The specific device and measuring means are as follows: the sample to be measured is placed in the pressure gauge, and the other end of the two glass plates is placed on the upper and lower sides of the sample to be measured, respectively. The fringe spacing d is measured by adjusting the reading microscope; the pressure gauge applies pressure to the sample to be measured, so that it is slightly deformed For a wedge (wedge-shaped film), assuming that the change of the included angle of the wedge is (a very small angle), and the length of the wedge is L. They approximately satisfy the relationship

[0045] (3)

[0046] Assuming that the included angle of the wedge changes from to , the fringe displacement is . Generally, when the angle change is very small, a simpler formula can be obtained according to the approximate relationship. Assuming that the initial angle of the wedge is ,if ,and ,So

[0047] (4)

[0048] In the formula, N is the number of aperture fringes that are displaced. For wedge interference, the fringe spacing d and the initial wedge angle are... Wavelength of light The relevant formula is... ,So Substituting it into (4) yields

[0049] (5)

[0050] Substituting equations (3) and (5) into equation (2), we get:

[0051] (6)

[0052] The shear modulus of the test item can be calculated using equation (6).

[0053] The following is an embodiment of this utility model: (e.g.) Figure 2 Assemble the instrument as shown. Place the pressure gauge 3 on the stage of the reading microscope. Fix one end of the two glass plates 10 together with the metal plate 5, and then place the other end of the two glass plates 10 on the worktable 16 of the pressure gauge 3. Next, place the object to be measured between the two glass plates 10. Connect the pressure gauge 3 to the computer via the wiring port 2. This allows the magnitude of the force applied by the pressure gauge to be converted into an electrical signal and reflected in real time on the computer screen. The pressure sensor and controller in the pressure gauge 3 can be used to check whether the pressure gauge is working properly. Place the light source 7 directly in front of the reading microscope.

[0054] First, the interferometer needs initial adjustment. Turn on the light source 7 (helium-neon laser source, laser wavelength), and adjust the height of the light source using knob 11 until it is at the same height as the fixed reflector 4. Then adjust the fixed reflector 4 as follows. Figure 5 As shown, the light from the light source 7 is reflected by the fixed mirror 4 onto the two glass plates 10, and then onto the objective lens 9, thus creating a bright field of view in the eyepiece 6. First, rotate the coarse adjustment knob 1 to slowly lower the objective lens 9 until it approaches the pressure gauge 3; look into the eyepiece 6 with your left eye, and at the same time, rotate the coarse adjustment knob 1 in the opposite direction to slowly raise the objective lens 9 until the image is clear. Then, slightly rotate the fine adjustment knob 8 to make the image even clearer, and check whether the aperture fringes can be clearly seen in the eyepiece 6.

[0055] After observing the clear aperture fringe, rotate the fine focus screw 8, measure the interval d of the aperture fringe, and output a constant pressure value F to the computer connected with the pressure gauge 3, as shown in Figure 3 The pressure gauge 3 receives and transmits instructions through the internal pressure sensor and the controller, and the movable weighing scale 15 moves, and the actuator 12 applies corresponding pressure to the measured object according to the instructions of the controller, as shown in Figure 4 , so that the measured object is slightly deformed, according to the principle shown in Figure 6 The displacement of the aperture fringe changes, the fine focus screw 8 is rotated again, the number N of the aperture fringe and the displacement are read out, the height H of the measured regular object is measured by the screw micrometer, and the length and width are calculated, and the shear surface area A of the measured object is calculated, then the length L of the split tip is measured by the vernier caliper. The above values are substituted into the following formula to calculate the shear modulus of the measured object:

[0056] .

[0057] It can be understood that the utility model is described through some embodiments, and those skilled in the art know that various changes or equivalent replacements can be made to these features and embodiments without departing from the spirit and scope of the utility model. In addition, under the guidance of the utility model, these features and embodiments can be modified to adapt to specific conditions and materials without departing from the spirit and scope of the utility model. Therefore, the utility model is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of the present application belong to the scope protected by the utility model.

Claims

1. A device for measuring the shear modulus of regular solid materials based on optical detection technology, characterized in that, The instrument includes a light source (7), a pressure gauge (3), a wedge interference plate, and a reading microscope. The pressure gauge (3) is placed on the stage of the reading microscope, and one end of the wedge interference plate rests on the worktable of the pressure gauge (3). The light source (7) is located directly opposite the reading microscope. The pressure gauge (3) applies pressure to the object to be measured to cause it to deform. The mirror (4) in the reading microscope reflects light through the light source (7), allowing the light to pass through the wedge interference plate and the objective lens (9) and eyepiece (6) in the reading microscope. The change in the aperture fringe displacement is then read out using the reading microscope.

2. The device for measuring the shear modulus of regular solid materials based on optical detection technology according to claim 1, characterized in that, The wedge interference plate consists of two glass plates (10) and a metal plate (5), with one end of the two glass plates (10) fixed together by the metal plate (5).

3. The device for measuring the shear modulus of regular solid materials based on optical detection technology according to claim 2, characterized in that, The two glass plates are 2-3 mm thick, 5-6 cm wide, and 65-80 cm long.

4. The device for measuring the shear modulus of regular solid materials based on optical detection technology according to claim 1, characterized in that, The pressure gauge includes a load frame, an actuator (12), a controller connection port (2), a limit device (17), and a pressure sensor; The load frame includes a column (13), an upper crossbeam (14), a movable crossbeam (15), a worktable (16), and a ball screw. The column (13) is vertically installed on both sides of the worktable, with its upper end fixedly connected to the upper crossbeam (14) and its lower end fixedly connected to the worktable, forming a rigid frame. The ball screw is installed on both sides inside the frame, with its upper end connected to the upper crossbeam 14 bearing and its lower end connected to the pulleys at both ends of the lower part of the frame table, forming a stable portal structure for supporting and guiding the movement of the movable crossbeam (15). The two ends of the movable crossbeam (15) are movably connected to the nut part of the ball screw. The transmission system of the movable crossbeam (15) is connected to the movable crossbeam (15) using a rolling screw and driven by a motor to realize the up and down movement of the movable crossbeam (15). The motor is embedded in the bottom of the load frame. The actuator (12) is fixed on the movable crossbeam (15); The controller is embedded inside the upper crossbeam (14); The wiring port (2) is fixed on the upper crossbeam; The limiting device (17) is embedded below the column to prevent the movable crossbeam (15) from exceeding the operating range; The pressure sensor is embedded inside the upper crossbeam (14).

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