CN116609175A - Young modulus measuring device and measuring method thereof - Google Patents

Abstract

The invention relates to a Young modulus measuring device and a measuring method thereof, wherein the measuring device comprises a first measuring mechanism, a second measuring mechanism and a third measuring mechanism, wherein the first measuring mechanism comprises a first base, an upper chuck, a lower chuck and a weight adjustable component; the upper clamping head is fixed on the first base, the upper clamping head and the lower clamping head respectively clamp the end parts of the metal wires, and the metal wires are straightened out by the upper clamping head and the lower clamping head; the lower chuck is connected with a weight-adjustable component; the metal wire is provided with an induction unit for monitoring the length change of the metal wire; a second measuring mechanism comprising a second base, a container, a conduit and a measuring cylinder; the second base supports a container, liquid is filled in the container, and a liquid outlet is formed in the container; the guide pipe is connected with the liquid outlet and the measuring cylinder and is provided with an automatic control valve; the control unit is respectively and electrically connected with the induction unit and the automatic control valve; the control unit collects the length change of the metal wire collected by the sensing unit and controls the opening or closing of the automatic control valve. The invention has simple structure and convenient use, and is beneficial to improving the accuracy of measurement.

Description

A Young's modulus measuring device and its measuring method

technical field

The invention relates to the technical field of experimental devices, in particular to a Young's modulus measuring device and a measuring method thereof.

Background technique

In the existing physical experiments, the optical lever method is usually used to measure the Young's modulus of the metal wire. The existing optical lever method requires the use of a scale telescope. The distance between the Young's modulus measuring instrument and the scale telescope is generally required to be about 1.5m. In order to facilitate debugging and observation, the two experimental instruments should be placed on two tables. , this will not only lead to a large space occupation, but also during the experiment, the experiment operator will go back and forth between the two instruments to adjust, observe and measure, and will inadvertently touch the table, which will lead to the failure of the experiment in serious cases;

In addition, before the optical lever method is measured, the experimenter needs to spend a lot of time and energy to call out the relationship between the telescope-optical lever small mirror-scale and the object-mirror-image incidence and reflection.

During the experiment, the small optical lever mirror is often damaged due to the careless drop of the experimenter, and the maintenance cost is high.

Therefore, there is an urgent need to design a Young's modulus measuring device that is simple to operate and saves space and time.

Contents of the invention

Aiming at the deficiencies of the prior art, the invention discloses a Young's modulus measuring device and a measuring method thereof.

The technical scheme adopted in the present invention is as follows:

A Young's modulus measuring device, comprising:

The first measuring mechanism includes a first base, an upper clamp, a lower clamp and an adjustable weight assembly; the upper clamp is fixed on the first base, the upper clamp and the lower clamp The ends of the metal wire are clamped respectively, and the metal wire is straightened at the upper clamp and the lower clamp; the lower clamp is connected to the weight adjustable component; the metal wire is provided with an induction unit, to monitor the change in length of said wire;

The second measuring mechanism includes a second base, a container, a conduit and a measuring cylinder; the second base supports the container, the container is filled with liquid and the container offers a liquid outlet; one end of the conduit is connected to the The liquid outlet is equipped with an automatic control valve, and the other end of the conduit is connected to the measuring cylinder;

A control unit is electrically connected to the sensing unit and the automatic control valve; the control unit collects the length change of the metal wire collected by the sensing unit, and controls the opening or closing of the automatic control valve.

In some embodiments, the adjustable weight assembly includes a weight plate and at least one weight, and the weight plate includes a hook, a connecting rod and a supporting base, and the connecting rod connects the hook and the supporting base respectively , the weight can be placed on the support seat; the lower chuck has a connecting portion, and the connecting portion is provided with a through hole for hanging the hook.

In some embodiments, the first base includes an upper beam, a lower beam, a base, and a set of uprights, a set of uprights are vertically fixed to the base, and the upper beam and the lower beam are sheathed on the base. The upright column, and the upper beam and the lower beam are parallel to each other; the upper beam supports the upper chuck; the lower beam is provided with a through hole, and the end of the metal wire passes through the through hole.

In some embodiments, the cross-sectional shape of the container is the same at different heights.

In some embodiments, the cross section of the container may be one of circular, elliptical and polygonal.

In some embodiments, the liquid is water.

In some embodiments, the control unit is a STM32 series microcontroller; the sensing unit is a length sensor.

In some embodiments, the first base and the second base are respectively provided with at least one counterweight, and the counterweight prevents the first base and the second base from rolling over. .

A kind of measuring method, utilizes Young's modulus measuring device as described above to measure, comprises the following steps:

Measure the initial diameter of the wire, the diameter of the container and the initial length of the wire between the upper beam and the induction unit;

The metal wire is deformed through the weight adjustable component. When the sensing unit senses the change in the length of the metal wire, the control unit controls the automatic control valve to open, and the liquid in the container flows into the measuring cylinder through the catheter until the sensing unit cannot sense the change of the metal wire. So far, the control unit controls the automatic control valve to close, and reads out and records the volume inside the measuring cylinder.

In some embodiments, the formula for calculating Young's modulus is as follows:

In the formula, Y is the Young's modulus, mg is the weight of the weight-adjustable component, _L0 is the initial length of the wire between the upper beam and the induction unit, D is the diameter of the container, and ΔV is the changing volume of the liquid in the container , d is the initial diameter of the wire.

The above technical solution of the present invention has the following advantages compared with the prior art:

The Young's modulus measuring device of the present invention is based on the existing Young's modulus measuring instrument, adding induction units, platforms, containers, conduits, automatic control valves and measuring cylinders, and reducing polished rods, telescopes and ruler devices.

The Young's modulus measuring device of the present invention can only be placed on one experimental table, and occupies a small area; it does not require the experimenter to walk back and forth between the two tables, effectively preventing the experimenter from touching the table inadvertently; and does not require debugging The complex optical path system saves experimental time; no optical lever is used, which greatly reduces maintenance costs.

The Young's modulus measuring device of the invention is simple in structure, easy to use, and beneficial to improving the accuracy of measurement.

Description of drawings

In order to make the content of the present invention more clearly understood, the present invention will be further described in detail below according to the specific embodiments of the present invention and in conjunction with the accompanying drawings.

Fig. 1 is a schematic diagram of a Young's modulus measuring device in the present invention.

Fig. 2 is a functional block diagram of the sensing unit, the control unit and the automatic control valve in the present invention.

Description of reference signs in the manual: 1. Upper chuck; 2. Column; 3. Lower beam; 4. Lower chuck; 5. Weight; 6. Weight plate; 7. Base; 8. Upper beam; 9. Metal 10, induction unit; 11, second base; 12, container; 13, liquid; 14, automatic control valve; 15, catheter; 16, measuring cylinder.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, so that those skilled in the art can better understand the present invention and implement it, but the examples given are not intended to limit the present invention.

The aforementioned and other technical contents, features and effects of the present invention will be clearly presented in the following detailed description of the embodiments with reference to the accompanying drawings. The directional terms mentioned in the following embodiments, such as: up, down, left, right, front or back, etc., are only referring to the directions of the drawings. Therefore, the directional terms used are used to illustrate and not to limit the present invention. Moreover, the same reference numerals represent the same elements throughout the embodiments.

It is found through experimental research that the existing optical lever method is used to measure the Young's modulus of the metal wire, the experiment occupies a large space, the experiment operation is cumbersome and complicated, and the experiment process is easy to damage the experiment equipment, resulting in the failure of the experiment.

Therefore, the present invention proposes a Young's modulus measuring device and a measuring method thereof.

Referring to Fig. 1, a Young's modulus measuring device includes a first measuring mechanism, a second measuring mechanism and a control unit.

Wherein, the first measuring mechanism includes a first base, an upper clamp 1, a lower clamp 4 and an adjustable weight assembly; the upper clamp 1 is fixed on the first base, and the upper clamp 1 and the lower clamp 4 clamp respectively Hold the end of the metal wire 9, and the metal wire 9 is straightened on the upper chuck 1 and the lower chuck 4; the lower chuck 4 is connected to the weight-adjustable component; the metal wire 9 is provided with an induction unit 10 to monitor the length of the metal wire 9 Variety. Preferably, the metal wire 9 is a steel wire, and the steel wire has ductility and malleability.

Specifically, the first base includes an upper beam 8, a lower beam 3, a base 7 and a set of columns 2, a set of columns 2 are vertically fixed to the base 7, the upper beam 8 and the lower beam 3 are sleeved on the column 2, and the upper beam 8 and the lower beam 3 are parallel to each other; the upper beam 8 supports the upper chuck 1; the lower beam 3 has a through hole through which the end of the wire 9 passes.

The weight adjustable assembly includes a weight plate 6 and at least one weight 5. The weight plate 6 includes a hook, a connecting rod and a support base. The connecting rods are respectively connected to the hook and the support base. The weight 5 can be placed on the support base; the lower clip The head 4 has a connecting portion, and the connecting portion is provided with a through hole for hanging a hook. Specifically, the connecting portion may be a mounting block fixedly connected to the lower chuck 4, a through hole penetrating through the mounting block is opened along the length direction of the mounting block, and the hook is hung on the through hole. Wherein, the way of fixed connection may be one of integral molding, welding, bolt connection, riveting and bonding.

The second measuring mechanism comprises a second base 11, a container 12, a conduit 15 and a measuring cylinder 16; the second base 11 supports the container 12, and the container 12 is equipped with a liquid 13 and the container 12 offers a liquid outlet; one end of the conduit 15 is connected to the liquid outlet The mouth is equipped with an automatic control valve 14, and the other end of the conduit 15 is connected with a graduated cylinder 16. Wherein, the second base 11 is liftable and adjustable in level. For example, the second base 11 includes a platform plate, a lifting drive source such as a single-acting cylinder and a base plate, and the action part of the lifting drive source is connected to the platform plate. The fixing of the lifting drive source The part is installed on the bottom plate, and the platform plate supports the container 12. When the second base 11 needs to be adjusted in height, the lifting drive source is started, and the action part of the lifting drive source acts on the platform plate, and the platform plate is lifted to achieve height adjustment; in addition, The mounting part of the lifting drive source can be fixed on the base plate by bolts. When the second base 11 needs to adjust the horizontal position, loosen the bolts, reselect the installation position of the lifting drive source on the base plate, and fix it by bolts.

Specifically, the cross-sectional shape of the container 12 at different heights is the same, and the cross-sectional shape of the container 12 may be one of circular, elliptical and polygonal. In this embodiment, the cross-section of the container 12 is circular, which is convenient for measuring and calculating the cross-sectional area of the container 12 . Liquid 13 is water or other solution.

The control unit is electrically connected with the sensing unit 10 and the automatic control valve 14 respectively; as shown in FIG.

Specifically, the control unit is a STM32 series single-chip microcomputer. Further, STM32F103C8T6 is used in this embodiment, and the sensing unit 10 is a length sensor. Preferably, the length sensor can be an inductive sensor with a tubular structure.

Preferably, the first base and the second base 11 are respectively provided with at least one counterweight to prevent the first base and the second base 11 from rolling over.

Installation principle of the present invention is as follows:

The metal wire 9 to be tested is fixed and straightened through the upper chuck 1 and the lower chuck 4, the weight plate 6 is connected to the lower chuck 4, the sensing unit 10 is fixed on the metal wire 9 to be tested and aligned with the container 12, the container 12 is placed on the second base 11 to ensure that the second base 11 is level, pour liquid into the container 12 until it is at the same level as the sensor unit 10 or slightly higher, and the automatic control valve 14 is installed near the container 12 to discharge the liquid One end of the conduit 15 of mouth, the other end of conduit 15 stretches into measuring cylinder 16.

The working principle of the present invention is as follows:

Measure the initial diameter of the wire 9, the diameter of the container 12 and the initial length of the wire 9 between the upper beam 8 and the induction unit 10;

The metal wire 9 is deformed by the adjustable weight assembly. When the sensing unit 10 senses the change in the length of the metal wire 9, the control unit controls the automatic control valve 14 to open, and the liquid 13 in the container 12 flows into the measuring cylinder 16 through the conduit 15 until the induction unit 10 senses the change of the length of the wire 9. Until the unit 10 senses no changes in the metal wire 9, the control unit controls the automatic control valve 14 to close, reads and records the volume inside the measuring cylinder 16, and calculates the Young's modulus by the following formula:

In the formula, Y is Young's modulus, mg is the weight of the adjustable weight component, _L0 is the initial length of the metal wire 9 between the upper beam 8 and the sensing unit 10, D is the diameter of the container 12, and ΔV is the diameter of the container 12 The changing volume of the inner liquid 13, d is the initial diameter of the wire 9.

The following compares the Young's modulus measurement method provided by the present invention with the existing optical lever method to prove the reliability and convenience of the measurement method provided by the present invention.

Example 1:

S1. Measuring the length: First, put a weight 5 with a mass of 0.36kg on the weight plate 6, straighten and tighten the metal wire 9, and measure the distance between the upper beam 8 and the induction unit 10 with a meter ruler. The length L ₀ of the metal wire 9, the diameter d of the six different positions of the metal wire 9 measured by the screw micrometer, and the inner diameter D of the six different positions of the vernier caliper measuring container 12 are recorded in the data form (see Table 1);

S2. Adjust the liquid level of the liquid 13 in the container 12: put the container 12 on the second base 11, add water to the container 12 to a height slightly higher than the sensing unit 10, turn on the power, and the sensing unit 10 senses When the length of the metal wire 9 changes, the control unit controls the automatic control valve 14 to open, and the liquid 13 in the container 12 enters the measuring cylinder 16 through the conduit 15 until the sensing unit 10 cannot detect the change in the length of the metal wire 9, and the control unit controls the automatic control valve 14 closure.

S3, measurement reading: first directly read the volume of the liquid 13 in the measuring cylinder 16, then put each weight 5 with a mass of 0.36kg on the weight plate 6 one by one, and read the volume of the liquid 13 in the measuring cylinder 16 successively, A total of five weights 5 are added to obtain six different volume readings V, which are recorded in the table.

S4. Calculation: Calculate the volume change ΔV corresponding to the weight 5 before and after the calculation, find out the Young's modulus Y, calculate the uncertainty and write out the result.

Table 1 embodiment raw data and calculation table

Comparative example 1:

S1. Measure the length; firstly, put a weight with a mass of 0.36kg on the weight plate, straighten and tighten the wire, and measure the length L of the wire between the upper beam and the lower beam with a meter ruler. ₀ , measure the optical lever constant Z with a vernier caliper, measure the distance D between the optical lever and the telescope with a meter ruler, and measure the diameter d of six different positions of the metal wire with a screw micrometer, and record it in the data table (see Table 2);

S2, adjust the optical path system;

S2.1. Place the two front legs of the optical lever in the groove of the workpiece platform, and the rear legs on the plane of the lower chuck. Adjust the plane of the plane mirror to make it perpendicular to the table.

S2.2. Adjust the height of the telescope lens barrel and the plane mirror so that the telescope lens barrel is perpendicular to the plane mirror.

S2.3. Preliminary search for the image of the ruler. Use your eyes to directly observe the reflection of the plane mirror from outside the telescope barrel, and see if there is an image of the scale in the mirror. If not, move the telescope scale holder left and right, and observe the plane mirror until the image of the scale is seen in the plane mirror.

S2.4. Adjust the telescope to find the image of the ruler. First adjust the telescope eyepiece to see a clear crosshair; then adjust the focus handwheel to make the image of the scale on the crosshair plane clear.

S2.5. Adjust the mirror surface of the plane mirror so that it is perpendicular to the optical axis of the telescope, and make the horizontal line of the telescope crosshair just press the zero scale line of the scale or be close to the zero scale.

S3. Use a scale telescope to measure the reading of the cross wire: read the position reading of the cross wire on the scale, then place each weight with a mass of 0.36kg on the weight plate one by one, and read the position of the cross wire on the scale in turn For the reading, add 5 weights in total to get the reading A of six positions, and record it in the form.

S4. Calculation: Calculate ΔA, find Young's modulus Y, calculate uncertainty and write out the result.

Table 2 The experimental raw data and calculation form of the comparative example

Table 3 embodiment and comparative example result contrast

As can be seen from Table 3, the Young's modulus measurement method provided by the present invention does not require the experimenter to walk back and forth between the two tables, effectively preventing the experimenter from touching the table inadvertently; it also does not need to debug a complicated optical path system, saving experimental time ; Light levers are not used, greatly reducing maintenance costs. Therefore, the Young's modulus measuring device provided by the present invention has a simple structure, is convenient to use, and is beneficial to improving measurement accuracy.

In the description of the embodiments of the present invention, it should also be noted that, unless otherwise specified and limited, the terms "setting" and "connection" should be interpreted in a broad sense, for example, it can be a fixed connection or an optional connection. Detachable connection, or integral connection; it can be mechanical connection or electrical connection; it can be direct connection or indirect connection through an intermediary, and it can be the internal communication of two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention in specific situations.

Apparently, the above-mentioned embodiments are only examples for clear description, and are not intended to limit the implementation. For those of ordinary skill in the art, on the basis of the above description, other changes or changes in various forms can also be made. It is not necessary and impossible to exhaustively list all the implementation manners here. However, the obvious changes or changes derived therefrom are still within the scope of protection of the present invention.

Claims (10)

1. A young's modulus measuring device, characterized in that: comprising the following steps:

the first measuring mechanism comprises a first base, an upper chuck (1), a lower chuck (4) and a weight-adjustable component; the upper clamping head (1) is fixed on the first base, the upper clamping head (1) and the lower clamping head (4) respectively clamp the end parts of the metal wires (9), and the metal wires (9) are straightened out on the upper clamping head (1) and the lower clamping head (4); the lower chuck (4) is connected with the weight-adjustable component; the wire (9) is provided with a sensing unit (10) to monitor the length change of the wire (9);

a second measuring mechanism comprising a second base (11), a container (12), a conduit (15) and a measuring cylinder (16); the second base (11) supports the container (12), liquid (13) is filled in the container (12), and a liquid outlet is formed in the container (12); one end of the guide pipe (15) is connected with the liquid outlet and is provided with an automatic control valve (14), and the other end of the guide pipe (15) is connected with the measuring cylinder (16);

the control unit is electrically connected with the induction unit (10) and the automatic control valve (14) respectively; the control unit collects the length change of the metal wire (9) collected by the sensing unit (10) and controls the automatic control valve (14) to be opened or closed.

2. Young's modulus measuring device according to claim 1, characterized in that: the weight-adjustable assembly comprises a weight tray (6) and at least one weight (5), wherein the weight tray (6) comprises a hook, a connecting rod and a supporting seat, the connecting rod is respectively connected with the hook and the supporting seat, and the weight (5) can be placed on the supporting seat; the lower chuck (4) is provided with a connecting part, and the connecting part is provided with a through hole for hanging the hook.

3. Young's modulus measuring device according to claim 1, characterized in that: the first base comprises an upper cross beam (8), a lower cross beam (3), a base (7) and a group of upright posts (2), wherein the group of upright posts (2) are vertically fixed on the base (7), the upper cross beam (8) and the lower cross beam (3) are sleeved on the upright posts (2), and the upper cross beam (8) and the lower cross beam (3) are parallel to each other; the upper cross beam (8) supports the upper chuck (1); the lower cross beam (3) is provided with a through hole, and the end part of the metal wire (9) passes through the through hole.

4. Young's modulus measuring device according to claim 1, characterized in that: the cross-sectional shape of the container (12) at different heights is the same.

5. Young's modulus measuring device according to claim 1, characterized in that: the cross-section of the container (12) may be one of circular, elliptical and polygonal.

6. Young's modulus measuring device according to claim 1, characterized in that: the liquid (13) is water.

7. Young's modulus measuring device according to claim 1, characterized in that: the control unit is a singlechip of STM32 series; the sensing unit (10) is a length sensor.

8. Young's modulus measuring device according to claim 1, characterized in that: the first base and the second base (11) are respectively provided with at least one balancing weight, and the balancing weights are used for preventing the first base and the second base (11) from turning on one side.

9. A measurement method using the young's modulus measuring device according to any one of claims 1 to 8, characterized by comprising the steps of:

measuring the initial diameter of the wire (9), the diameter of the container (12) and the initial length of the wire (9) between the upper cross beam (8) and the induction unit (10), respectively;

the metal wire (9) is deformed through the weight-adjustable component, when the sensing unit (10) senses the length change of the metal wire (9), the control unit controls the automatic control valve (14) to be opened, liquid (13) in the container (12) flows into the measuring cylinder (16) through the guide pipe (15) until the sensing unit (10) cannot sense the change of the metal wire (9), and the control unit controls the automatic control valve (14) to be closed, reads and records the inner volume of the measuring cylinder (16).

10. The measurement method according to claim 9, characterized in that: the formula for calculating Young's modulus is as follows:

wherein Y is Young's modulus, mg is the weight of the weight-adjustable component, L ₀ The initial length of the wire (9) between the upper beam (8) and the sensing unit (10), D is the diameter of the container (12), deltaV is the changing volume of the liquid (13) in the container (12), and D is the initial diameter of the wire (9).