CN102636123A

CN102636123A - Young's modulus of metal wire measured by Michelson interference

Info

Publication number: CN102636123A
Application number: CN2012101073227A
Authority: CN
Inventors: 胡再国; 邹旭敏; 王维果
Original assignee: Sichuan University
Current assignee: Sichuan University
Priority date: 2012-04-13
Filing date: 2012-04-13
Publication date: 2012-08-15

Abstract

The invention discloses a Young's modulus of a metal wire measured by Michelson interference and relates to the field of measuring of Young's modulus. The current Young's modulus measuring apparatus has the defects of small metal wire variation, poor measuring precision of many length parameters due to limits of the apparatus and difficulty in regulation of the apparatus. In order to overcome the defects of the current Young's modulus measuring apparatus and obtain more accurate measurement, the tiny elongation of the metal wire is measured by using a Michelson interference method disclosed by the invention. The technical scheme is as follows: one end of the metal wire is fixed at a plane mirror of a Michelson interferometer device; force is slowly applied to elongate the metal wire so that interference fringes move; and the number of the interference fringes is counted, the count variation of a tension sensor is obtained, the length of the metal wire is determined, the diameter of the metal wire is measured by using a micrometer, and then the Young's modulus of the metal wire is calculated. The Young's modulus of the metal wire measured by the Michelson interference has the advantages of accurate measurement, intuitive variation and simplicity in operation, reflects the mutual technology integration when being used for college physics experiments and improves the interests of students in conducting experiments.

Description

Michelson interferometry tinsel Young modulus

Technical field

The present invention relates to the measurement of Young modulus, particularly use Michelson interference technique measuring young modulus.

Background technology

Young modulus is the classical experiment of of Experiment of College Physics; But elongation is smaller during owing to measurement; The general optical lever that adopts is amplified, the number of increase and decrease counterweight, and the scale mark number that a certain straight line of graticule crossed in the scale image drift in the observation telescope obtains the variable quantity of tinsel length.

Young modulus causes measurement length to have any problem because variable quantity is little, and tinsel is sandwiched between two chucks; The distance of measuring light lever and scale generally adopts the unsettled measurement of tape measure, and whether wait vertical with scale all can be brought the error of measurement with tape measure in the bending of tape measure; The optical lever rear foot is also lower to the range measurement accuracy of minute surface; The level crossing of telescope, optical lever and the relative adjustment between the scale are also relatively more difficult.

Summary of the invention

In order to overcome the difficulty of existing modulus measurer, in order to measure Young modulus wiry more accurately, the method that the present invention adopts Michelson to interfere is measured small elongation wiry.

The technical scheme that the present invention solves its technical matters employing is: the bottom, the other end that an end wiry are fixed on Michelson interferometer are fixed on the level crossing of Michelson interference device; After the tinsel tensile elongation, cause level crossing to move and bring optical path difference; Interference fringe is moved; When the weight change that stretches is slow; Just can observe moving of striped one by one, can adopt the infusion set of similar hospital to obtain a pulling force that slowly changes, obtain the variable quantity of pulling force through pulling force sensor.

The invention has the beneficial effects as follows: measure accurately; Change directly perceived; Simple to operate; Be used for the mutual fusion that Experiment of College Physics more can embody technology, improve student experimenting interest.

Description of drawings

Fig. 1 is a Michelson interferometry Young modulus synoptic diagram.

Wherein, 1, the tinsel point of fixity, 2, tinsel, 3, fixed pulley, 4, level crossing; 5, level crossing base sleeve, 6, beam splitter, 7, level crossing, 8, film viewing screen, 9, pulling force sensor; 10, support, 11, water container, 12, the water flow velocity control handle, 13, metal drum.

Embodiment

Tinsel 2 every interval 1mm spray a kind of color, make tinsel carry length measurement function, advise that every interval 10mm spraying is red, other position spray black, if technology allows, and the best ring-type spraying of color.Also can be when the design Michelson interferometer, fixing two reference positions (level crossing 4 is in one of them reference position), the distance that makes two reference positions is a fixed length, so just can omit measurement of length.

Water container 11 is formed the device that similar hospital infuses with water flow velocity control handle 12, and flow speed control is proper 100 milliliters-200 milliliters of per minutes, and water container 11 is suspended on the firm support 10.

Tinsel point of fixity 1 is a starting point wiry, and tinsel is walked around two fixed pulleys 3 then, is fixed on the level crossing base sleeve 5, and tinsel continues forward through a fixed pulley, and the hanging metal bucket 13 then.

Michelson is interfered and is made up of semiconductor laser, beam expanding lens, beam splitter 6, level crossing 4 and level crossing 7.Open laser power supply; The position of regulating laser instrument makes laser can shine level crossing 4 and level crossing 7, and the position of adjusting level crossing 7 and inclination angle make sees on the film viewing screen 8 that the little interference fringe that occurs after two spots coincide (for simplifying regulating step, can make level crossing 4 and level crossing 7 equal to the distance of beam splitter 6 during manufacturing; So only need to regulate the inclination angle of level crossing 7; The little interference fringe that occurs after two spots coincide is got final product), beam expanding lens is introduced light path, on film viewing screen, see bigger interference fringe this moment; The inclination angle of fine setting level crossing 7 makes sees round striped on the film viewing screen, the position that changes level crossing 7 can change the size of round striped.

When the striped on the film viewing screen is suitable; The reading of record pulling force sensor 9 at this moment; The flow velocity of the control water of the flow speed control of fetching boiling water knob 12, water flows to metal drum 13 from water container 11 through liquid-transport pipe-line, and the reading of observing change of interference fringes number and pulling force sensor 9 changes.

According to optical maser wavelength and number of interference fringes obtain elongation wiry, according to the reading of pulling force sensor 9 change the black number that the size, the number that obtain pulling force go out beauty's chromatic number (cms) and the two point of fixity redness outside between two point of fixity of tinsel obtain length wiry, with miking diameter wiry, just can calculate Young modulus wiry after these data have been arranged.

Claims

1. Michelson interferometry tinsel Young modulus of the present invention; Be to use Michelson interferometry elongation wiry, it is characterized in that: bottom, the other end that an end wiry is fixed on Michelson interferometer are fixed on the level crossing of Michelson interference device; Cause level crossing to move after the pulling force that slowly changes slowly extends tinsel and bring optical path difference to change, observe moving of striped one by one; When the striped on the film viewing screen is suitable; The reading of record pulling force sensor at this moment; The flow velocity of the control water of the flow speed control of fetching boiling water knob; Water flows to metal drum from water container through liquid-transport pipe-line, and the reading of observing change of interference fringes number and pulling force sensor changes, and reading length wiry just can be calculated Young modulus wiry with measurement diameter wiry.

2. Michelson interferometry tinsel Young modulus according to claim 1; It is characterized in that: the every interval 1mm of tinsel sprays a kind of color; Make tinsel carry length measurement function, advise that every interval 10mm spraying is red, other position spray black; If technology allows, the best ring-type spraying of color.

3. Michelson interferometry tinsel Young modulus according to claim 1; It is characterized in that: the pulling force that slowly changes is to form the device that similar hospital infuses through water container and water flow velocity control handle to realize; Liquid flows to the metal drum that is suspended on the tinsel; Flow speed control is proper 100 milliliters-200 milliliters of per minutes, and water container is suspended on the firm support.