Young modulus measuring device for experiment teaching

Abstract

The utility model discloses a Young modulus measuring device for experiment teaching, which comprises a test frame, a cylinder, a pressure piece, a piston and a graduated tube, a fixing assembly is arranged on the test frame, and a piece to be measured is fixed on the fixing assembly; the cylinder is arranged on the test frame; the pressure piece is connected to the piece to be tested; the piston is arranged in the air cylinder and is connected with the pressure piece; the graduated tube is arranged on one side of the testing frame and is connected with the air cylinder through a connecting tube; according to the device, the metal wire can be stretched through the pressure piece, the piston is pressed downwards, so that the detection liquid in the air cylinder flows into the graduated tube, a hydraulic transmission mechanism is formed, the Young modulus of the piece to be detected can be obtained by detecting the liquid level change height of the air cylinder and the change height of the liquid level in the graduated tube and combining a Young modulus calculation formula, the structure is simple, and the operation is convenient. The device is simple in structure, convenient to operate, low in manufacturing cost, suitable for school experiment teaching, and capable of realizing measurement of tiny length and improving the measurement precision.

Description

Technical Field

[0001] The utility model relates to the technical field of material research and application, in particular to a Young's modulus measuring device for experimental teaching. Background Art

[0002] Young's modulus is a physical quantity that characterizes the properties of a material and depends only on the physical properties of the material itself. Young's modulus is a physical quantity that reflects the relationship between the size of the material's deformation and its internal stress. The determination of Young's modulus is of great significance in studying the mechanical properties of various materials such as metal materials, optical fiber materials, semiconductors, nanomaterials, polymers, ceramics, rubber, etc. It can also be used in the fields of mechanical parts design, biomechanics, geology, etc.

[0003] In existing physical experiments, the methods for measuring Young's modulus generally include stretching method, beam bending method, vibration method, etc. There are also experimental techniques and methods using optical fiber displacement sensors, moiré fringes, eddy current sensors, and wave transmission technology (microwave or ultrasonic). The stretching method and bending method require more parameters to be measured and have low accuracy; the vibration method has a high cost and is difficult to operate. In addition, some experimental methods using sensors involve precision instruments, which are expensive and are not suitable for university physics experimental teaching. Therefore, it is necessary to design a teaching device for measuring Young's modulus that is simple to operate and saves time and cost. Utility Model Content

[0004] In view of the above-mentioned deficiencies of the prior art, the purpose of the present invention is to provide an experimental teaching device for measuring Young's modulus, aiming to solve the problems of low measurement accuracy and high cost of tiny length quantities in the prior art.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] In a first aspect, a Young's modulus measuring device for experimental teaching comprises:

[0007] A test stand, wherein a fixing assembly is provided on the test stand, and a test piece is fixed on the fixing assembly;

[0008] A cylinder, which is arranged on the test frame and located at the lower end of the test piece, and is filled with a test liquid;

[0009] A pressure piece, connected to the test piece and located at the upper end of the cylinder;

[0010] A piston, disposed in the cylinder and connected to the pressure member;

[0011] The calibrated tube is arranged on one side of the test frame and connected to the cylinder through a connecting tube.

[0012] Furthermore, the test stand comprises:

[0013] Base;

[0014] The bracket is arranged on the base.

[0015] Further, the fixing assembly comprises:

[0016] A first fixture, disposed at the upper end of the bracket and connected to one end of the test piece;

[0017] A second fixture is disposed in the middle of the bracket, and a through hole is opened in the middle of the second fixture to accommodate the test piece;

[0018] The third fixer is arranged at the lower end of the bracket and is connected to the cylinder.

[0019] Furthermore, the pressure member comprises:

[0020] A tray, connected to one end of the test piece facing the cylinder and connected to the piston;

[0021] A weight is placed on the tray to apply pressure to the piston.

[0022] Furthermore, the tray and the piston are connected via a connecting rod.

[0023] Furthermore, the test piece includes a metal wire.

[0024] Furthermore, the graduated tube comprises a glass tube, and the glass tube is engraved with graduations.

[0025] Furthermore, the connecting pipe comprises a rubber tube.

[0026] Furthermore, the calibrated tube is fixedly connected to one side of the test stand via a fixing clamp.

[0027] The technical solution adopted by the utility model has the following beneficial effects:

[0028] In the present application, the metal wire can be stretched by the pressure piece and the piston can be pressed down, so that the detection liquid in the cylinder can flow into the calibrated tube to form a hydraulic transmission mechanism. By detecting the change in the liquid level in the cylinder and the change in the liquid level in the calibrated tube, combined with the Young's modulus calculation formula, the Young's modulus of the test piece can be obtained. The structure is simple, the operation is easy, the production cost is low, and it can be applied to school experimental teaching. It can realize the measurement of tiny length quantities and improve the measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The utility model provides a structural schematic diagram of a Young's modulus measuring device for experimental teaching.

[0030] 1. Base; 2. Bracket; 3. First fixture; 4. Cylinder; 5. Piston; 6. Measured object; 7. Tray; 8. Connecting pipe; 9. Second fixture; 10. Scale tube; 11. Fixing clip; 12. Weight; 13. Third fixture; 14. Connecting rod. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and effect of the utility model clearer and more specific, the utility model is further described in detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0032] It should be noted that when a component is referred to as being "fixed to" or "disposed on" another component, it can be directly on the other component or indirectly on the other component. When a component is referred to as being "connected to" another component, it can be directly connected to the other component or indirectly connected to the other component.

[0033] It should also be noted that the same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the drawings, it is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as limitations on this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0034] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0035] A Young's modulus measurement device for experimental teaching, please refer to Figure 1 , which includes a test stand, a cylinder 4, a pressure piece, a piston 5, and a graduated tube 10. The test stand is provided with a fixing assembly, and a test piece 6 is fixed on the fixing assembly; the cylinder 4 is provided on the test stand; the pressure piece is connected to the test piece 6; the piston 5 is provided in the cylinder 4 and connected to the pressure piece; the graduated tube 10 is provided on one side of the test stand and connected to the cylinder 4 through a connecting pipe 8;

[0036] In this embodiment, please refer to Figure 1 The metal wire can be stretched by the pressure piece, and the piston 5 is pressed down, so that the detection liquid in the cylinder 4 flows into the graduated tube 10, forming a hydraulic transmission mechanism. By detecting the change height of the liquid level in the cylinder 4 and the change height of the liquid level in the graduated tube 10, combined with the Young's modulus calculation formula, the Young's modulus of the test piece 6 can be obtained. It has a simple structure, easy operation, low production cost, and is suitable for school experimental teaching. It can realize the measurement of tiny length quantities and improve the measurement accuracy.

[0037] In the implementation of the present utility model, please refer to Figure 1 , the test piece 6 is a metal wire, and the test frame is composed of a base 1 and a bracket 2, and the bracket 2 is arranged on the base 1; in addition, the fixing assembly includes a first fixture 3, a second fixture 9 and a third fixture 13; the first fixture 3 is arranged at the upper end of the bracket 2, and is connected to one end of the test piece 6 to fix the test piece 6; the second fixture 9 is arranged in the middle of the bracket 2, and a through hole is opened in the middle of the second fixture 9 to accommodate the test piece 6, which can keep the test piece 6 stable, thereby improving the measurement accuracy of the Young's modulus of the test piece 6; the third fixture 13 is arranged at the lower end of the bracket 2, and is connected to the cylinder 4.

[0038] In this example, see Figure 1 The pressure member includes a tray 7 and a weight 12. The tray 7 is connected to one end of the test piece 6 facing the cylinder 4 and is connected to the piston 5. The weight 12 is placed on the tray 7 to apply pressure to the piston 5. By increasing or decreasing the weight 12, the size of the force of squeezing the piston 5 and the length of the stretched wire can be changed.

[0039] In this example, see Figure 1 The tray 7 and the piston 5 are connected by a connecting rod 14 so that the tray 7 and the piston 5 can be in close contact, ensuring that the liquid level in the cylinder 4 can change with the change of the weight 12, thereby improving the measurement accuracy.

[0040] In the embodiments of the present invention, please refer to Figure 1 The graduated tube 10 comprises a glass tube with graduations engraved thereon. When the detection liquid changes, the amount of change in the liquid level can be recorded by reading the graduation value, which is convenient for data recording.

[0041] In this example, see Figure 1 The connecting tube 8 is a rubber tube. When a certain liquid column is squeezed out of the outer glass tube, bubbles can be discharged by squeezing the rubber tube to ensure the air tightness of the instrument.

[0042] In this example, see Figure 1The calibrated tube 10 is fixedly connected to one side of the test stand by a fixing clamp 11 to ensure the stability of the calibrated tube 10 .

[0043] In order to better demonstrate the specific effect of this device, a specific embodiment is provided below:

[0044] First, fix the test piece 6 to the upper beam (first fixture 3), put a weight 12 with a mass of m0 on the tray 7, straighten the test piece 6 to be taut, measure the length L of the test piece 6 once with a ruler, measure the diameter d of the test piece 6 at six different positions with a micrometer and record them in a table, then adjust the lower beam (third fixture 13) to a suitable position, make the tray 7 and the piston 5 rigidly fixedly connected through the connecting rod 14, use the connecting pipe 8 to connect the graduated tube 10 and the cylinder 4, and ensure that the rubber tube has no sharp bends.

[0045] Inject water into the cylinder 4. If bubbles appear in the liquid column, push the cylinder piston 5 to discharge the liquid column with bubbles until there are no bubbles in the connecting tube 8 and the graduated tube 10 after pushing the cylinder piston 5. Squeeze the connecting tube 8 to adjust the liquid level of the graduated tube 10 to a suitable position (generally not exceeding 1 / 2 of the total length), and write down the reading of the liquid column on the graduated tube 10.

[0046] First, read the liquid level L1 in the graduated tube 10, then add 7 weights 12 (320g / each) with a mass of m0 on the tray 7 in sequence, squeeze the piston 5 to stretch and change the deformation of the test piece 6, and record the reading of the graduated tube 10 each time the weight 12 is added, and 8 different liquid level readings are obtained and recorded in a table.

[0047] Subtract the 7 weights 12 on the weight tray in turn to reduce the pressure on the piston 5, change the deformation of the test piece 6, and record the reading of the graduated tube 10 each time the weight 12 is subtracted, and obtain 8 different liquid level readings again and record them in the table.

[0048] The data obtained by adding and subtracting weight 12 are averaged, and the deformation variable ΔL of the test piece can be obtained by using the difference method to process the data, and the value of Young's modulus can be calculated. The measurement uncertainty and relative error can be obtained through data analysis. The experiment lasts 12 minutes.

[0049] The diameter of the cylinder 4 is D1, the diameter of the graduated tube 10 is D2, the small change of the liquid level in the cylinder 4 is L1, and the large change of the liquid level in the graduated tube 10 is L2. The relationship between L1 and L2 is:

[0050]

[0051] The final calculation formula of Young's modulus is:

[0052]

[0053] Among them, σ is the uniaxial stress; ε is the strain; F is the tension on the wire, which is numerically equal to the gravity of weight 4; A is the cross-sectional area of ​​the wire; L is the initial length of the wire; ΔL is the elongation of the wire under the action of force F, which is numerically equal to the change in the liquid level in the piston L1; m0 is the weight of the weight on the tray; D1 is the diameter of the cylinder 4; D2 is the diameter of the graduated tube 10; L1 and L2 are the changes in the liquid level in the cylinder 4 and the changes in the liquid level in the graduated tube 10 respectively; d is the diameter of the wire.

[0054] Finally, the Young's modulus of the test piece 6 is obtained.

[0055] It can be seen from the embodiments that the Young's modulus measurement method provided by the utility model takes up little space, does not require the experimenter to move back and forth, and effectively saves time and space; requires very little data to be measured, saving experimental time; has a simple structure, does not use precision instruments, and greatly reduces experimental costs. Therefore, the Young's modulus measurement device provided by the utility model is suitable for widespread use in higher education experimental teaching.

[0056] Those skilled in the art will readily come up with other embodiments of the present invention after considering the specification and practicing the solutions disclosed herein. The present invention is intended to cover any variations, uses or adaptations of the present invention, which follow the general principles of the present invention and include common knowledge or customary technical means in the art that are not disclosed in the present disclosure. The specification and examples are to be regarded as exemplary only, and the true scope and spirit of the present invention are indicated by the claims.

Claims

1. A Young's modulus measuring device for experimental teaching, characterized in that: It includes: A test stand, wherein a fixing assembly is provided on the test stand, and a test piece is fixed on the fixing assembly; A cylinder, which is arranged on the test frame and located at the lower end of the test piece, and is filled with a test liquid; A pressure piece, connected to the test piece and located at the upper end of the cylinder; A piston, disposed in the cylinder and connected to the pressure member; The calibrated tube is arranged on one side of the test frame and connected to the cylinder through a connecting tube.

2. The Young's modulus measuring device for experimental teaching according to claim 1, characterized in that: The test frame comprises: Base; The bracket is arranged on the base.

3. The Young's modulus measuring device for experimental teaching according to claim 2, characterized in that: The fixed components include: A first fixture, disposed at the upper end of the bracket and connected to one end of the test piece; A second fixture is disposed in the middle of the bracket, and a through hole is opened in the middle of the second fixture to accommodate the test piece; The third fixer is arranged at the lower end of the bracket and is connected to the cylinder.

4. The Young's modulus measuring device for experimental teaching according to claim 1, characterized in that: The pressure piece comprises: A tray, connected to one end of the test piece facing the cylinder and connected to the piston; A weight is placed on the tray to apply pressure to the piston.

5. The Young's modulus measuring device for experimental teaching according to claim 4, characterized in that: The tray and the piston are connected via a connecting rod.

6. The Young's modulus measuring device for experimental teaching according to claim 1, characterized in that: The object to be tested includes a metal wire.

7. The Young's modulus measuring device for experimental teaching according to claim 1, characterized in that: The graduated tube comprises a glass tube, and graduations are engraved on the glass tube.

8. The Young's modulus measuring device for experimental teaching according to claim 1, characterized in that: The connecting pipe comprises a rubber tube.

9. The Young's modulus measuring device for experimental teaching according to claim 1, characterized in that: The calibrated tube is fixedly connected to one side of the test frame through a fixing clamp.

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