CN103018109A - Tester for Young's modulus - Google Patents

Abstract

The invention discloses a Young's modulus tester, which is characterized in that it comprises a cylindrical container and a disc installed at the mouth of the cylindrical container, and a communicating conduit is arranged on the cylindrical container, and one end of the conduit is There is a liquid injection chamber, which is connected with a thin glass tube for display, and a dial corresponding to the thin glass tube for display. It also includes a weight, which is connected to the metal to be measured on the bracket. The wire is connected so that the weight acts on the disc. Therefore, by measuring the mass of the weight, the radius of the thin glass tube, and the rising height of the solution in the thin glass tube, the strength of the wire pulling force can be calculated, and then the length and cross-sectional area of the metal wire can be measured to calculate Yang. modulus. It solves the complicated operation of the current experimental equipment and the error problem of measurement data.

Description

Young's modulus tester

technical field

The invention relates to a Young's elastic modulus tester used for measuring metal by a static stretching method. Effectively improve the accuracy of measurement data.

Background technique

Young's modulus of elasticity is an important physical quantity to describe the elastic deformation ability of solid materials, and it is also one of the basis for selecting mechanical component materials, and it is also a commonly used parameter in engineering technology.

Young's modulus is a physical quantity that describes the ability of a solid material to resist deformation. A wire of length L and cross-sectional area S is stretched by ΔL under the action of a force F. F/S is called stress, and its physical meaning is the force per unit cross-sectional area of the metal wire; ΔL/L is called strain, and its physical meaning is the elongation corresponding to the unit length of the metal wire. The ratio of stress to strain is called modulus of elasticity, also known as Young's modulus.

After measuring the quantities on the right side of the equal sign according to the above formula, Young's modulus can be calculated. Among them, F, L and S can be measured by general methods, but the value of elongation ΔL is very small, and it is difficult to measure accurately with general tools.

Due to the shortcomings of the above-mentioned experimental process, the operation of the instrument is complicated, and the error of the experimental data is large, in order to solve this problem, the disclosed instrument and experimental method have been improved. like:

1 Gao Hailin of Henan Industrial Vocational and Technical College improved the experimental device with a vernier caliper, and properly improved the experimental method and process, which improved the reliability and measurement accuracy of the experiment.

2 Chen Weiwei and Liu Yanfeng from the Physics Department of Mudanjiang Normal University improved the telescope and optical lever, which reduced the difficulty of adjustment, simplified the experimental process, reduced the experimental error, and improved the measurement accuracy of Young's modulus.

3 Dou Jinlan, Wang Xinchun, Shen Jiawang, and Wang Kunlin from the Department of Physics and Electronic Technology of Chuxiong Normal University combined the principle of light amplification and used a one-time increase (decrease) weight to repeatedly read the scale value of the scale.

4 Zhu Wei and Yang Qinglei, College of Mathematics and Physics, Qingdao University of Science and Technology, through the improvement of the optical system, the adjustment process is more intuitive, which overcomes the blindness of adjustment and relatively shortens the adjustment time of the instrument.

5 Department of Physics, Qiongzhou University, Huang Huairen modified the measurement device, which simplifies the measurement process relatively, reduces the chance of error generation and improves the measurement accuracy to a certain extent.

6 Zhao Min, Qiang Xiaoming, and Zhang Weifang from the School of Electronic Information Engineering, Hefei Normal University replaced the original scale telescope with a micro-laser, which relatively improved the measurement accuracy and significantly improved the operability of the experiment.

To sum up, through the above-mentioned improvements, compared with traditional tools, there is indeed a certain improvement in measurement. However, it is still relatively complicated for the operation of the experimental equipment, and the measured data also has certain errors, and the amount of amplification of the elongation ΔL is not very large.

Contents of the invention

In view of the above-mentioned present situation, the purpose of the present invention is to provide an improved static stretching method for measuring Young's elastic modulus tester of metal, which can quickly and accurately measure the elongated length of the metal wire to be tested.

In order to achieve the above object, the technical solution of the present invention is: a Young's modulus tester, comprising a cylindrical container, and a disc installed at the mouth of the cylindrical container, on which a connected Conduit, one end of the conduit is provided with a liquid injection cavity, a display thin glass tube is connected with the liquid injection cavity, and there is a dial corresponding to the display thin glass tube, and a weight is configured, and the weight is connected to the bracket The metal wire to be tested on is connected so that the weight acts on the disc. When the liquid medium is placed in the cylindrical container, the metal wire to be tested is stretched, the liquid in the cylindrical container is discharged, and the liquid level in the thin glass tube is recorded by the dial.

In the present model, the center of the end surface on one side of the disc involved has a concave arc. When used in contact with a weight, keep the weight in the center of the disc.

In the present invention, it also includes a liquid-insulating membrane or a liquid-insulating bag installed in the cylindrical container. The liquid in the cylindrical container can be prevented from overflowing during the test process by using a liquid barrier film or a liquid barrier bag.

The positive effect of the present invention is: use the weight to act on the metal wire to be tested, the metal wire is elongated, and the height of the solution in the thin glass tube is used to calculate the tiny elongation of the metal wire to be tested to form a special testing instrument . By measuring the mass of the weight, the radius of the thin glass tube, and the rising height of the solution in the thin glass tube, the force of pulling the wire can be calculated, and then the length and cross-sectional area of the metal wire can be measured to calculate Young's modulus quantity. It has the characteristics of easy operation and high testing accuracy. Compared with the measurement of traditional tools, the present invention has a certain improvement. However, it is still relatively complicated for the operation of the experimental equipment, and there are still certain errors in the measured data, and the amount of amplification of the elongation ΔL is not very large.

Description of drawings

Fig. 1 is the schematic diagram of the present invention.

Detailed ways

The present invention will be further described below in conjunction with the embodiments of the accompanying drawings.

See the Young's modulus tester shown in Fig. 1, comprise cylindrical container 5, be provided with the conduit 12 that communicates with on described cylindrical container 5, this conduit 12 one ends are provided with an injection chamber 11, and injection chamber 11 is connected with a display thin glass tube 10, and has a dial 9 corresponding to the display thin glass tube 10. A sealing plug 13 is installed at the injection port of the liquid injection chamber 11 in this embodiment. Also includes a disk 4, the disk 4 is installed in the mouth of the cylindrical container 5 parts. The center of one side end surface of the disk 4 described in this embodiment has a concave arc 14 . When used in contact with a weight, keep the weight in the center of the disc. In the present invention, a weight 3 is also arranged, and the weight 3 is connected with the metal wire 2 to be tested connected to the support 1 , so that the weight 3 acts on the disk 4 . The above-mentioned support 1 is installed on a tripod stand 8 with a pallet 7 . In application, a liquid medium is placed in the cylindrical container 5 , and a liquid barrier film 6 is placed on the liquid medium in the cylindrical container 5 . The liquid in the cylindrical container 5 can be prevented from overflowing during the test process through the liquid barrier film 6 .

In the present model, in addition to selecting the mode of the liquid barrier film 6 for use, the liquid barrier bag (plastic bag) can also be selected for use. During use, the outlet of the liquid-separating bag should be connected with the inlet of the conduit 12 .

Experimental principle

Measurement of elongation ΔL:

When the weight of the weight increases, the metal wire to be tested is stretched to make it elongate by ΔL, and the weight descends at the same time, squeezing the disc 4, and the disc 4 also descends, squeezing the liquid in the cylindrical container 5 to make the cylindrical shape A part of the liquid in the device 5 flows into the thin glass tube 10 through the conduit 12, and the liquid level in the thin glass tube 10 will rise to a certain height.

By measuring the rising height of the liquid in the thin glass tube 10 , the radius of the thin glass tube 10 and the radius of the cylindrical container 5 , the elongation ΔL of the metal wire 2 to be measured can be obtained.

Assuming that the radius R=20cm of the thin glass tube 10 and the radius r=1mm of the cylindrical container 5, the magnification factor k=40000, which is equivalent to magnifying the elongation ΔL by 40000 times. At the same time, when R increases, r decreases Hours, the value of k will increase. The amplification of ΔL can be larger, and the enlarged length can be directly observed with the naked eye. At the same time, the error of the data is greatly reduced, the accuracy of the experiment is improved, and the operation of the experimental instrument becomes very simple.

Calculation of pulling force T:

Analyze the overall force of the weight and the disc, the upward buoyancy F floats, the upward pulling force T of the metal wire, and the downward gravity G=mg (m is the weight of the weight).

By measuring the mass of the weight, the radius of the thin glass tube, and the rising height of the solution in the thin glass tube, the force T of the wire pulling force can be calculated, and then the Young's modulus can be calculated by measuring the length and cross-sectional area of the wire. Y.

Steps

First record the height of the liquid level in the thin glass tube, then increase the mass of the weight, the metal wire to be tested is stretched, the liquid in the container is discharged, record the height of the liquid level in the thin glass tube again, and record the mass of the weight at the same time .

Claims (3)

1. Young modulus tester, it is characterized in that, comprise hydrostatic column (5), and be installed in the disk (4) of hydrostatic column (5) port part, be provided with the conduit (12) of connection at described hydrostatic column (5), these conduit (12) one ends are provided with a fluid injection chamber (11), be connected one with fluid injection chamber (11) and show thin glass tube (10), and with show that thin glass tube (10) is corresponding an index dial (9) arranged, also comprise and dispose counterweight (3), this counterweight (3) is connected with tinsel to be measured (2) on being connected to support (1), and counterweight (3) is acted on the disk (4).

2. a kind of Young modulus tester according to claim 1 is characterized in that, wherein the center of disk (4) one side end faces has a concave arc.

3. a kind of Young modulus tester according to claim 1 is characterized in that, also comprise be installed in the hydrostatic column (5) every liquid film (6) or every the liquid bag.

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