CN106018555A - Experimental device and method for measuring Young modulus with beam bending method based on resonance principle - Google Patents
Experimental device and method for measuring Young modulus with beam bending method based on resonance principle Download PDFInfo
- Publication number
- CN106018555A CN106018555A CN201610462707.3A CN201610462707A CN106018555A CN 106018555 A CN106018555 A CN 106018555A CN 201610462707 A CN201610462707 A CN 201610462707A CN 106018555 A CN106018555 A CN 106018555A
- Authority
- CN
- China
- Prior art keywords
- beams
- metal
- frequency
- sinusoidal signal
- spring oscillator
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/04—Analysing solids
- G01N29/045—Analysing solids by imparting shocks to the workpiece and detecting the vibrations or the acoustic waves caused by the shocks
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09B—EDUCATIONAL OR DEMONSTRATION APPLIANCES; APPLIANCES FOR TEACHING, OR COMMUNICATING WITH, THE BLIND, DEAF OR MUTE; MODELS; PLANETARIA; GLOBES; MAPS; DIAGRAMS
- G09B23/00—Models for scientific, medical, or mathematical purposes, e.g. full-sized devices for demonstration purposes
- G09B23/06—Models for scientific, medical, or mathematical purposes, e.g. full-sized devices for demonstration purposes for physics
- G09B23/08—Models for scientific, medical, or mathematical purposes, e.g. full-sized devices for demonstration purposes for physics for statics or dynamics
- G09B23/10—Models for scientific, medical, or mathematical purposes, e.g. full-sized devices for demonstration purposes for physics for statics or dynamics of solid bodies
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2291/00—Indexing codes associated with group G01N29/00
- G01N2291/01—Indexing codes associated with the measuring variable
- G01N2291/014—Resonance or resonant frequency
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2291/00—Indexing codes associated with group G01N29/00
- G01N2291/02—Indexing codes associated with the analysed material
- G01N2291/023—Solids
- G01N2291/0234—Metals, e.g. steel
Abstract
The invention relates to a device and a method for measuring Young modulus and discloses an experimental device and method for measuring the Young modulus with a beam bending method based on a resonance principle to solve the problems that the experimental principle is single and abstract, and a telescope is difficult to adjust in the current beam bending method for measuring the Young modulus. The device comprises two stand columns arranged on the base, wherein two ends of a metal beam with a rectangular section are freely placed at knife edges at upper ends of the stand columns in a crossing manner respectively, the metal beam is sleeved with a copper frame, a vibration exciter and a movable armature are arranged at the lower end of the metal frame, and the vibration exciter is connected with a signal source; a measuring device comprises a differential bridge consisting of two inductance coils and two resistors, an alternating voltage source, an amplification unit and an oscilloscope. According to the method, a sinusoidal signal is converted into mechanical vibration by the vibration exciter, so that a metal beam spring oscillator performs forced oscillation, the forced oscillation is converted into an electrical signal by the bridge formed by a variable inductor, the signal frequency is adjusted, the inherent frequency of a metal beam spring oscillator is obtained when the waveform amplitude is the highest, and the Young modulus is calculated. The experimental device and method are applicable to measurement of the Young modulus.
Description
Technical field
The present invention relates to a kind of Experiment of College Physics device, be specifically related to the beam deflection of a kind of resonance principle
Method surveys experimental provision and the method for Young's modulus.
Background technology
Under external force, the change of shape that solid is occurred, referred to as deformation.It can be divided into elastic deformation and
Plastic deformation two class.External force removes the complete restorable deformation of energy of rear object, referred to as elastic deformation.If
The external force being added on object is excessive, so that after external force is removed, object can not restore to the original state completely, and stays surplus
Remaining deformation, the most referred to as plastic deformation.In this experiment, elastic deformation is only studied.To this end, should control
The size of external force, with ensure this external force remove after object resilient.Simplest deformation is bar-like object
(or tinsel) is by the elongation after external force and shortening.If an a length of L of object, sectional area is S, along length side
After force F, object elongation (or shortening) is Δ L.Ratio F/S is the active force in unit are, is referred to as
Stress, which determine the deformation of object；Ratios delta L/L is the specific elongation of object, referred to as strain, and it represents
The size of object deformation.According to Hooke's law, the elastic limit internal stress at object is directly proportional to strain, than
Example coefficientIt is referred to as Young's modulus.
Experiment shows, Young's modulus is unrelated with the size of external force F, length L of object and sectional area S, and only
Depend on the material of rod (or tinsel).Young's modulus is describe solid material elastic deformation ability one
Important mechanics parameter, is one of foundation selecting mechanical component material, is parameter conventional in engineering.
No matter it is elastomeric material, such as various metal materials, or fragile material, such as glass, pottery etc., or
Other various new materials, such as fiberglass, carbon fibre composite etc., in order to ensure the use of normal safe,
Their Young's modulus will be measured.For a long time, the Young's modulus measuring material generally uses static stretch
Method, is typically carried out on universal testing machine.This method load is big, and loading velocity is slow, there is relaxation
Process, can increase measurement error, and be difficult to fragile material measure, measure also under condition of different temperatures
Inconvenient.The eighties in 20th century, there are people's laser-holographic interferometry and laser speckle photography method to aerospace field
The Young's modulus of carbon composite measure, carry out the impact on Young's modulus of the research material defect with this,
Achieve good effect.The nineties in 20th century, the kinetics i.e. hang wire of Young's modulus measuring method bends
Resonance method recommends to perform as national technical standard.This method can be measured in the range of bigger high/low temperature
The Young's modulus of various materials, and certainty of measurement is higher.Static method, except static stretch method, also has static state to turn round
Robin, the method for Static bending etc.；Dynamic method except lateral resonance, also longitudinal resonance, torsional resonance etc..Separately
Wave speed measurement method can also be used outward, utilize continuous wave or impulse wave to measure Young's modulus.
Although kinetics Young's modulus measuring method i.e. hang wire flexural resonance method has many good qualities, but by
Complicated in theoretical formula, principle is the most readily understood, and equipment is the most more complicated, and experiment difficulty is big, therefore the biggest
Learn in Physical Experiment frequently with beam deflection method, measure the Young mould of metal material according to optical lever amplification principle
Amount.Optical lever amplification principle has been widely used in measurement technology, such as ballistic galvanometer and light spot galvanometer
Measure low-angle change.The most also there is the some other more advanced micro-displacement measurement method of employing,
Such as current vortex sensor method, Michelson's interferometer method, optical fibre displacement sensor method etc. measure metal material
The Young's modulus of material.Experiment of College Physics central sill bending method surveys the experimental provision of metal material Young's modulus at present
It is primarily present following deficiency:
One, generally uses static stretch method to survey metal material Young's modulus, and principle is more single.
Its two, according to optical lever amplification principle, the amplification system formed by optical lever, telescope and scale
Measuring sag curved under beams of metal midpoint, square-section, although method is ingenious, but principle is more abstract, no
Readily understood, telescopical regulation difficulty is bigger, and points for attention are the most, and directly utilized by human eye
Telescope carries out observing to be measured, and is very easy to fatigue, easily data is mistaken, affect the accurate of measurement result
Property.
Its three, general use counterweight to apply pulling force to beams of metal, calculate pulling force with the nominal mass of counterweight and forbidden
Really, thus affect the accuracy of experimental result.
Summary of the invention
In order to overcome the above-mentioned deficiency of prior art, the present invention proposes the beam deflection method of a kind of resonance principle and surveys
The experimental provision of Young's modulus and method, experimental principle of the present invention is easily understood, and described experimental provision utilizes and swashs
The sinusoidal signal that sine signal source exports is converted to the mechanical vibration of same frequency by the device that shakes, and passes to by square-section
The beams of metal spring oscillator that beams of metal is constituted with copper framework, moving armature, iron block, makes beams of metal spring oscillator
Making forced vibration, this vibration is converted to periodically variable bridge output voltage by the change of inductance value,
The waveform of amplified bridge output voltage is observed on analog oscilloscope, by regulating the frequency of sinusoidal signal,
Until the wave-shape amplitude maximum of bridge output voltage, now the frequency of sinusoidal signal is exactly resonant frequency,
The namely natural frequency of beams of metal spring oscillator, experimental phenomena is directly perceived, observe with measure more convenient.
The present invention solves the experimental provision surveying Young's modulus by the beam deflection method of resonance principle of its technical problem
It is: two columns are set on pedestal each two column upper ends to fix a steel edge of a knife, two edges of a knife
Blade is parallel to each other, and beams of metal two ends, square-section freely ride upon on the edge of a knife of two column upper ends,
Overlapping a copper framework on the beams of metal of square-section, copper framework and beams of metal contact position, square-section are also one
The edge of a knife, and the copper framework edge of a knife is located exactly at the edge of a knife middle of two column upper ends, sets in copper framework lower end
Putting vibrator, vibrator is connected with a moving armature by attachment means, moving armature by attachment means and
One iron block is connected.Vibrator is connected with sine signal source by interface, the sinusoidal signal of sine signal source output
Voltage amplitude and frequency size can be continuously adjusted by knob, and can show on a display screen.
The sinusoidal signal that sine signal source exports is converted to the mechanical vibration of same frequency by vibrator, passes to and is cut by rectangle
The beams of metal spring oscillator that face beams of metal is constituted with copper framework, moving armature, iron block, makes beams of metal spring vibration
Son makees forced vibration.Two identical iron cores of specification are separately positioned on two fixtures, and fixture is arranged on
On column, fixture can move to change position along column, two identical inductance coils of specification rotating around
On two iron cores.Two inductance coils and two adjustable resistances collectively form a differential bridge, by adjustable
Alternating-current voltage source provides power supply, the sinusoidal signal voltage amplitude of adjustable alternating-current voltage source output and frequency to electric bridge
Size can be adjusted by knob, and can show on adjustable alternating-current voltage source display screen.Electric bridge
Outfan concatenation operation amplifier one, as a backward voltage amplifier, voltage amplification factor can be led to
The size crossing change adjustable feedback resistance and adjustable input resistance is adjusted, and is amplified by the output voltage of electric bridge,
Exporting through the operational amplifier two as output buffer, operational amplifier two is by interface and simulation oscillography again
Device is connected, and the waveform of the bridge output voltage after amplifying can be shown by analog oscilloscope, observes
With measurement.
The beam deflection method of resonance principle of the present invention is surveyed the experimental provision of Young's modulus and is surveyed metal material poplar
The experimental technique of family name's modulus, the detailed process of the method comprises the following steps:
Step one, by observing pedestal level gauge, adjust the pedestal leveling serew on pedestal, make square-section
Beams of metal level；
Step 2, along column movable clamp one and fixture two, make moving armature be positioned in iron core one and iron core two
Between, by adjustable alternating-current voltage source function switching key, adjustable alternating-current voltage source display screen shows respectively
The sinusoidal signal voltage amplitude of adjustable alternating-current voltage source output and frequency size, by adjustable alternating-current voltage source electricity
Pressure adjusting knob and adjustable alternating voltage source frequency adjusting knob are adjusted, and are exported by adjustable alternating-current voltage source
Sinusoidal signal voltage amplitude and frequency regulation suitable；By changing adjustable feedback resistance and adjustable input resistance
Size the voltage amplification factor of operational amplifier one is regulated suitable, after being amplified by analog oscilloscope
The waveform of bridge output voltage shows, observes the electric bridge after amplifying by analog oscilloscope display screen and exports
The waveform of voltage, carefully adjusts fixture one and the position of fixture two further, makes bridge output voltage along column
Being zero, now moving armature is positioned at iron core one and the middle of iron core two；
Step 3, by sinusoidal signal voltage amplitude adjusting knob and sinusoidal signal voltage amplitude display screen, will
The sinusoidal signal voltage amplitude regulation of sine signal source output is suitable, is revolved by regulation sinusoidal signal frequency coarse adjustment
Button is gradually increased the frequency of the sinusoidal signal of sine signal source output, and sine signal source is just being exported by vibrator
String signal is converted to the mechanical vibration of same frequency, pass to by square-section beams of metal and copper framework, moving armature,
The beams of metal spring oscillator that iron block is constituted, makes beams of metal spring oscillator make forced vibration, when the frequency of sinusoidal signal
When rate is away from the natural frequency of beams of metal spring oscillator, copper framework, moving armature, iron block are the most motionless or shake
Dynamic the faintest；When the frequency of sinusoidal signal moves closer to the natural frequency of beams of metal spring oscillator, based on
Resonance principle, copper framework, moving armature, the Oscillation Amplitude of iron block be gradually increased, and moving armature moves up and down
Time air gap be changed, the therefore change of the inductance value of inductance coil one and inductance coil two generating period therewith,
And one increase and one subtract, so that bridge output voltage the most periodically changes；
Step 4, this periodically variable bridge output voltage are after operational amplifier one amplifies, then through conduct
The operational amplifier two of output buffer exports, and waveform shows on analog oscilloscope, in simulation oscillography
Observe the waveform of the bridge output voltage after amplifying on device display screen, revolved by regulation sinusoidal signal frequency fine tuning
Button, the most carefully the frequency size of the sinusoidal signal of regulation sine signal source output, until electric bridge output electricity
Till the wave-shape amplitude maximum of pressure, the frequency now read from sinusoidal signal frequency display screen resonates frequently exactly
Rate, namely natural frequency f of beams of metal spring oscillator；
Step 5, treat beams of metal spring oscillator stop vibration, measure copper framework, moving armature, iron block total
Quality m, i.e. quality m of beams of metal spring oscillator beams of metal midpoint hanging object；
Step 6, measure the effective length of square-section beams of metal with meter ruler, namely lay this beam two
Distance l in the middle of two edges of a knife of column upper end, measures the width of beams of metal square-section, square-section with slide gauge
Degree b and height d；
Step 7, by length l of square-section beams of metal, width b, highly d, beams of metal midpoint hanger
Quality m of body, and the natural frequency f substitution formula of beams of metal spring oscillatorCan ask
Go out Young's modulus Y of beams of metal material.
Theoretical basis by the beam deflection method survey Young's modulus of resonance principle:
If an a length of l, width are b, height is the square-section beams of metal of d, when its two ends freely across
Putting on the pair of parallel horizontal edge of a knife, when midpoint is by downward pulling force F effect, beam will be bent downwardly,
If sag curved under beam midpoint is h, if the Young's modulus of beams of metal material is Y, if disregarding the weight of beam, and
And bending is in elastic limit, as h ＜ ＜ l, has
(1) formula is become
According to (2) formula as, this square-section beams of metal can be regarded a coefficient of elasticitySpring.
The object that a mass is m, then beams of metal spring and this object structure is hung in this square-section beams of metal midpoint
Become a beams of metal spring oscillator, apply certain pulling force to this system, then discharge, then object will be in vertically side
Upwards doing simple harmonic oscillation, its cycle can be obtained by the Period Formula of spring oscillator, i.e.
The natural frequency of beams of metal spring oscillator is can be obtained fom the above equation
Coefficient of elasticity by beams of metal spring(4) formula of substitution, can obtain
According to (5) formula, Young's modulus Y wiry can be obtained, i.e.
Applied vibration source is acted on beams of metal spring oscillator, makes beams of metal spring oscillator make forced vibration.When
When the frequency in applied vibration source is not equal to the natural frequency of beams of metal spring oscillator, beams of metal spring oscillator is almost
Do not vibrate or Oscillation Amplitude is the least；When the frequency in applied vibration source is equal to the natural frequency of beams of metal spring oscillator
Time, based on resonance principle, the Oscillation Amplitude of beams of metal spring oscillator will increase suddenly.Measure the most additional shaking
Frequency f in dynamic source, i.e. natural frequency f of beams of metal spring oscillator.Measure square-section beams of metal length l,
Width b, highly d, quality m of beams of metal spring oscillator beams of metal midpoint hanging object, it is possible to according to public affairs
Formula (6), obtains Young's modulus Y of beams of metal material.
The invention has the beneficial effects as follows:
One, the present invention proposes a kind of new method surveying Young's modulus by the beam deflection method of resonance principle, should
The method method that the usual beam deflection method used surveys metal material Young's modulus with Physical Experiments exists
Essence different, and the experimental principle of the method institute foundation is the simplest, it is simply that common mass-spring model
And resonance principle, high school physics class just has been directed to correlation formula, course of University Physics also has detailed
Analyze, be easily understood.If therefore this invention is incorporated in Physical Experiments, it is remarkably contributing to rich
Rich Experiment of College Physics content, the thinking of open student, the initiative spirit of training student, strengthen student flexible
Use knowledge problem-solving ability.
Its two, it is the most multiple that what the present invention proposed surveys the experimental provision of Young's modulus by the beam deflection method of resonance principle
Miscellaneous, improve a little on the basis of existing experimental provision, be easier to realize.
Its three, the present invention propose experimental provision utilize vibrator the sinusoidal signal that sine signal source exports to be turned
It is changed to the mechanical vibration of same frequency, passes to by square-section beams of metal and copper framework, moving armature, iron block structure
The beams of metal spring oscillator become, makes beams of metal spring oscillator make forced vibration, this vibration change by inductance value
Change and be converted to periodically variable bridge output voltage, analog oscilloscope is observed amplified electric bridge defeated
Go out the waveform of voltage, by regulating the frequency of sinusoidal signal, until the wave-shape amplitude of bridge output voltage is maximum
Till, now the frequency of sinusoidal signal is exactly resonant frequency, namely the natural frequency of beams of metal spring oscillator,
Experimental phenomena is directly perceived, observe with measure more convenient.
Accompanying drawing explanation
The present invention is further described with embodiment below in conjunction with the accompanying drawings.
Fig. 1 is the structural representation one of the present invention.
Fig. 2 is the structural representation two of the present invention.
1. pedestal in figure, 2. pedestal level gauge, 3. pedestal leveling serew, 4. column, 5. the column edge of a knife,
6. square-section beams of metal, 7. copper framework, 8. the copper framework edge of a knife, 9. vibrator, 10. moving armature,
11. sine signal sources, 12. sinusoidal signal frequency display screens, 13. sinusoidal signal frequency coarse adjustment knobs, 14. just
String signal frequency fine tuning knob, 15. sinusoidal signal voltage amplitude display screens, 16. sinusoidal signal voltage amplitudes are adjusted
Joint knob, the interface between 17. vibrators and sine signal source, 18. iron blocks, 19. inductance coils one, 20.
Inductance coil two, 21. iron cores one, 22. iron cores two, 23. attachment means, 24. fixtures one, 25. fixtures two,
26. adjustable resistances one, 27. adjustable resistances two, 28. adjustable alternating-current voltage sources, 29. adjustable alternating-current voltage sources show
Display screen, 30. adjustable alternating-current voltage source voltage-regulation knobs, 31. adjustable alternating voltage source frequency adjusting knobs,
32. adjustable alternating-current voltage source function switching keys, 33. adjustable feedback resistance, 34. operational amplifiers one, 35.
Adjustable input resistance, 36. operational amplifiers two, 37. analog oscilloscopes, 38. analog oscilloscope display screens, 39.
Analog oscilloscope switch key.
Detailed description of the invention
In figure, pedestal 1 arranges two columns 4, each two column 4 upper ends fixes a steel edge of a knife,
The i.e. column edge of a knife 5, the blade of two edges of a knife is parallel to each other, and square-section beams of metal 6 two ends freely ride upon
On the edge of a knife of two column 4 upper ends, square-section beams of metal 6 overlaps a copper framework 7, copper framework 7 with
Square-section beams of metal 6 contact position is also an edge of a knife, i.e. the copper framework edge of a knife 8, and the copper framework edge of a knife 8 is proper
It is positioned at well the edge of a knife middle of two column upper ends, vibrator 9, vibrator are set in copper framework 7 lower end
9 are connected with a moving armature 10 by attachment means, and moving armature 10 is by attachment means 23 and an iron block
18 are connected.Vibrator 9 is by the interface 17 between vibrator with sine signal source and sine signal source 11 phase
Even, the sinusoidal signal voltage amplitude of sine signal source 11 output can be by the regulation rotation of sinusoidal signal voltage amplitude
Button 16 continuously adjusts, and can show on sinusoidal signal voltage amplitude display screen 15；Sinusoidal letter
Number frequency size can be entered by sinusoidal signal frequency coarse adjustment knob 13 and sinusoidal signal frequency fine tuning knob 14
Row continuously adjusts, and can show on sinusoidal signal frequency display screen 12.Vibrator 9 is by sinusoidal signal
The sinusoidal signal of source 11 output is converted to the mechanical vibration of same frequency, passes to by square-section beams of metal 6 and copper
The beams of metal spring oscillator that framework 7, moving armature 10, iron block 18 are constituted, makes beams of metal spring oscillator be subject to
Compel vibration.Two i.e. iron cores 1 of the identical iron core of specification and iron core 2 22 are separately positioned on two folders
On tool i.e. fixture 1 and fixture 2 25, fixture 1 and fixture 2 25 are arranged on column 4, fixture
1 and fixture 2 25 can move to change position along column 4, two identical inductance coils of specification
I.e. inductance coil 1 and inductance coil 2 20 are rotating around on iron core 1 and iron core 2 22.Two electricity
Sense coil i.e. inductance coil 1, inductance coil 2 20 and two i.e. adjustable resistances 1 of adjustable resistance, can
Resistance 2 27 is adjusted to collectively form a differential bridge.Power supply is provided to electric bridge by adjustable alternating-current voltage source 28,
Sinusoidal signal voltage amplitude and the frequency size of the output of adjustable alternating-current voltage source 28 can be respectively by adjustable exchanges
Voltage source voltage-regulation knob 30 and adjustable alternating voltage source frequency adjusting knob 31 are adjusted, and can be
Show on adjustable alternating-current voltage source display screen 29.The outfan concatenation operation amplifier 1 of electric bridge, fortune
Calculation amplifier 1 is as a backward voltage amplifier, and voltage amplification factor can be by changing adjustable feedback
The size of resistance 33 and adjustable input resistance 35 is adjusted, and is amplified by the output voltage of electric bridge, then through making
Operational amplifier 2 36 for output buffer exports, and operational amplifier 2 36 is by interface and simulation oscillography
Device 37 is connected, and the waveform of the bridge output voltage after amplifying can be shown by analog oscilloscope 37, enters
Row is observed and is measured.
Specific experiment operating procedure is:
(1) by observing pedestal level gauge 2, adjust the pedestal leveling serew 3 on pedestal 1, make rectangle cut
Face beams of metal 6 level.
(2) along column 4 movable clamp 1 and fixture 2 25, moving armature 10 is made to be positioned at iron core 1
And in the middle of iron core 2 22, by adjustable alternating-current voltage source function switching key 32, show at adjustable alternating-current voltage source
Sinusoidal signal voltage amplitude and frequency size that adjustable alternating-current voltage source 28 exports is shown respectively in display screen 29,
Carried out by adjustable alternating-current voltage source voltage-regulation knob 30 and adjustable alternating voltage source frequency adjusting knob 31
Regulation, the sinusoidal signal voltage amplitude exported by adjustable alternating-current voltage source 28 and frequency regulation are suitable.By changing
Become the size of adjustable feedback resistance 33 and adjustable input resistance 35 by the voltage amplification of operational amplifier 1 times
Number regulation is suitable, and the waveform of the bridge output voltage after being amplified by analog oscilloscope 37 is shown.Logical
Cross analog oscilloscope display screen 38 and observe the waveform of the bridge output voltage after amplifying, young along column 4 further
Fine control fixture 1 and the position of fixture 2 25, making bridge output voltage is zero, now moving armature 10
It is positioned at iron core 1 and the middle of iron core 2 22.
(3) by sinusoidal signal voltage amplitude adjusting knob 16 and sinusoidal signal voltage amplitude display screen 15,
The sinusoidal signal voltage amplitude regulation exported by sine signal source 11 is suitable.Thick by regulation sinusoidal signal frequency
Adjusting knob 13 to be gradually increased the frequency of the sinusoidal signal that sine signal source 11 exports, sine is believed by vibrator 9
The sinusoidal signal of number source 11 output is converted to the mechanical vibration of same frequency, pass to by square-section beams of metal 6 with
The beams of metal spring oscillator that copper framework 7, moving armature 10, iron block 18 are constituted, makes beams of metal spring oscillator do
Forced vibration.When the frequency of sinusoidal signal is away from the natural frequency of beams of metal spring oscillator, copper framework 7, live
Moving armature 10, iron block 18 are the most motionless or vibration is the faintest；When the frequency of sinusoidal signal moves closer to metal
During the natural frequency of beam spring oscillator, based on resonance principle, copper framework 7, moving armature 10, iron block 18
Oscillation Amplitude is gradually increased, and when moving armature 10 moves up and down, air gap is changed, therefore inductance coil 1
And the change of the inductance value of inductance coil 2 20 generating period therewith, and one increase and one subtract, so that electric bridge is defeated
Go out voltage the most periodically to change.
(4) this periodically variable bridge output voltage is after operational amplifier 1 amplifies, then through conduct
Operational amplifier 2 36 output of output buffer, waveform shows on analog oscilloscope 37, at mould
Intend observing on oscilloscope display screen 38 waveform of the bridge output voltage after amplifying, by regulation sinusoidal signal frequency
Rate fine tuning knob 14, the most carefully the frequency size of the sinusoidal signal of regulation sine signal source 11 output, directly
To the wave-shape amplitude maximum of bridge output voltage, now read from sinusoidal signal frequency display screen 12
Frequency is exactly resonant frequency, namely natural frequency f of beams of metal spring oscillator.
(5) treat that beams of metal spring oscillator stops vibration, measure copper framework 7, moving armature 10, iron block 18
Gross mass m, i.e. quality m of beams of metal spring oscillator beams of metal midpoint hanging object.
(6) measure the effective length of square-section beams of metal 6 with meter ruler, two that namely lay this beam vertical
Distance l in the middle of two edges of a knife of post 4 upper end, measures square-section beams of metal 6 square-section with slide gauge
Width b and height d.
(7) by length l of square-section beams of metal 6, width b, highly d, beams of metal midpoint hanging object
Quality m, and beams of metal spring oscillator natural frequency f substitute into formulaCan obtain
Young's modulus Y of beams of metal material.
Above the present invention is set forth, but the most conditional intention of embodiment that the present invention is introduced,
In the range of without departing substantially from present subject matter, the present invention can have multiple changing and modifications.
Claims (2)
1. survey the experimental provision of Young's modulus by the beam deflection method of resonance principle, it is characterised in that it is included in
Arranging two columns on pedestal, each two column upper ends fix a steel edge of a knife, the blade of two edges of a knife is mutual
Parallel, beams of metal two ends, square-section freely ride upon on the edge of a knife of two column upper ends, at rectangle
Overlapping a copper framework on cross section metal beam, copper framework and beams of metal contact position, square-section are also edges of a knife,
And the copper framework edge of a knife is located exactly at the edge of a knife middle of two column upper ends, exciting is set in copper framework lower end
Device, vibrator is connected with a moving armature by attachment means, and moving armature is by attachment means and an iron block
It is connected；Vibrator is connected with sine signal source by interface, the sinusoidal signal voltage amplitude of sine signal source output
Degree and frequency size can be continuously adjusted by knob, and can show on a display screen, vibrator
The sinusoidal signal that sine signal source exports is converted to the mechanical vibration of same frequency, passes to by square-section metal
The beams of metal spring oscillator that beam is constituted with copper framework, moving armature, iron block, makes beams of metal spring oscillator be subject to
Compel vibration；
Two identical iron cores of specification are separately positioned on two fixtures, and fixture is arranged on column, folder
Tool can move to change position along column, and two identical inductance coils of specification are rotating around at two iron cores
On.Two inductance coils and two adjustable resistances collectively form a differential bridge, by adjustable alternating-current voltage source
Thering is provided power supply to electric bridge, sinusoidal signal voltage amplitude and the frequency size of the output of adjustable alternating-current voltage source can be led to
Cross knob to be adjusted, and can show on adjustable alternating-current voltage source display screen；The outfan of electric bridge is even
Connecing operational amplifier one, as a backward voltage amplifier, voltage amplification factor can be adjustable by changing
The size of feedback resistance and adjustable input resistance is adjusted, and is amplified by the output voltage of electric bridge, then through conduct
The operational amplifier two of output buffer exports, and operational amplifier two is connected with analog oscilloscope by interface,
The waveform of the bridge output voltage after amplifying can be shown by analog oscilloscope, observes and measures.
The beam deflection method of resonance principle the most according to claim 1 is surveyed the experimental provision of Young's modulus and is surveyed
The experimental technique of metal Young's modulus, it is characterised in that the detailed process of the method comprises the following steps:
Step one, by observing pedestal level gauge, adjust the pedestal leveling serew on pedestal, make square-section
Beams of metal level；
Step 2, along column movable clamp one and fixture two, make moving armature be positioned in iron core one and iron core two
Between, by adjustable alternating-current voltage source function switching key, adjustable alternating-current voltage source display screen shows respectively
The sinusoidal signal voltage amplitude of adjustable alternating-current voltage source output and frequency size, by adjustable alternating-current voltage source electricity
Pressure adjusting knob and adjustable alternating voltage source frequency adjusting knob are adjusted, and are exported by adjustable alternating-current voltage source
Sinusoidal signal voltage amplitude and frequency regulation suitable；By changing adjustable feedback resistance and adjustable input resistance
Size the voltage amplification factor of operational amplifier one is regulated suitable, after being amplified by analog oscilloscope
The waveform of bridge output voltage shows, observes the electric bridge after amplifying by analog oscilloscope display screen and exports
The waveform of voltage, carefully adjusts fixture one and the position of fixture two further, makes bridge output voltage along column
Being zero, now moving armature is positioned at iron core one and the middle of iron core two；
Step 3, by sinusoidal signal voltage amplitude adjusting knob and sinusoidal signal voltage amplitude display screen, will
The sinusoidal signal voltage amplitude regulation of sine signal source output is suitable, is revolved by regulation sinusoidal signal frequency coarse adjustment
Button is gradually increased the frequency of the sinusoidal signal of sine signal source output, and sine signal source is just being exported by vibrator
String signal is converted to the mechanical vibration of same frequency, pass to by square-section beams of metal and copper framework, moving armature,
The beams of metal spring oscillator that iron block is constituted, makes beams of metal spring oscillator make forced vibration, when the frequency of sinusoidal signal
When rate is away from the natural frequency of beams of metal spring oscillator, copper framework, moving armature, iron block are the most motionless or shake
Dynamic the faintest；When the frequency of sinusoidal signal moves closer to the natural frequency of beams of metal spring oscillator, based on
Resonance principle, copper framework, moving armature, the Oscillation Amplitude of iron block be gradually increased, and moving armature moves up and down
Time air gap be changed, the therefore change of the inductance value of inductance coil one and inductance coil two generating period therewith,
And one increase and one subtract, so that bridge output voltage the most periodically changes；
Step 4, this periodically variable bridge output voltage are after operational amplifier one amplifies, then through conduct
The operational amplifier two of output buffer exports, and waveform shows on analog oscilloscope, in simulation oscillography
Observe the waveform of the bridge output voltage after amplifying on device display screen, revolved by regulation sinusoidal signal frequency fine tuning
Button, the most carefully the frequency size of the sinusoidal signal of regulation sine signal source output, until electric bridge output electricity
Till the wave-shape amplitude maximum of pressure, the frequency now read from sinusoidal signal frequency display screen resonates frequently exactly
Rate, namely natural frequency f of beams of metal spring oscillator；
Step 5, treat beams of metal spring oscillator stop vibration, measure copper framework, moving armature, iron block total
Quality m, i.e. quality m of beams of metal spring oscillator beams of metal midpoint hanging object；
Step 6, measure the effective length of square-section beams of metal with meter ruler, namely lay this beam two
Distance l in the middle of two edges of a knife of column upper end, measures the width of beams of metal square-section, square-section with slide gauge
Degree b and height d；
Step 7, by length l of square-section beams of metal, width b, highly d, beams of metal midpoint hanger
Quality m of body, and the natural frequency f substitution formula of beams of metal spring oscillatorCan ask
Go out Young's modulus Y of beams of metal material.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610462707.3A CN106018555A (en) | 2016-06-17 | 2016-06-17 | Experimental device and method for measuring Young modulus with beam bending method based on resonance principle |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610462707.3A CN106018555A (en) | 2016-06-17 | 2016-06-17 | Experimental device and method for measuring Young modulus with beam bending method based on resonance principle |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN106018555A true CN106018555A (en) | 2016-10-12 |
Family
ID=57086531
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610462707.3A Pending CN106018555A (en) | 2016-06-17 | 2016-06-17 | Experimental device and method for measuring Young modulus with beam bending method based on resonance principle |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN106018555A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110412126A (en) * | 2019-07-18 | 2019-11-05 | 中国科学院金属研究所 | A kind of measuring method of single crystal super alloy elastic constant |
| CN110455929A (en) * | 2019-07-31 | 2019-11-15 | 江苏大学 | A kind of high-frequency vibration breaking test device and method of off-resonance form |
| CN111208325A (en) * | 2020-03-03 | 2020-05-29 | 东南大学 | Four-end measuring clamp capable of achieving accurate positioning |
-
2016
- 2016-06-17 CN CN201610462707.3A patent/CN106018555A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110412126A (en) * | 2019-07-18 | 2019-11-05 | 中国科学院金属研究所 | A kind of measuring method of single crystal super alloy elastic constant |
| CN110412126B (en) * | 2019-07-18 | 2021-08-03 | 中国科学院金属研究所 | Method for measuring elastic constant of single crystal high-temperature alloy |
| CN110455929A (en) * | 2019-07-31 | 2019-11-15 | 江苏大学 | A kind of high-frequency vibration breaking test device and method of off-resonance form |
| CN111208325A (en) * | 2020-03-03 | 2020-05-29 | 东南大学 | Four-end measuring clamp capable of achieving accurate positioning |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104777054B (en) | A kind of parameter identification method of the resonant mode fatigue crack propagation test vibrational system based on soft-measuring technique | |
| CN103175602B (en) | Modal testing system and modal testing method on basis of single-point laser continuous plane-scanning vibration measurement | |
| CN103943001B (en) | Circular polarization string of a musical instrument standing wave demonstrating instrument | |
| CN106018555A (en) | Experimental device and method for measuring Young modulus with beam bending method based on resonance principle | |
| CN105806708A (en) | Experimental device and method for measuring Young modulus of metal wire according to simple harmonic vibration | |
| CN105810053A (en) | Experimental device and method for measuring Young's modulus of steel wire through resonance phenomenon | |
| CN209265789U (en) | A kind of young modulus measuring device based on Wheatstone bridge | |
| CN106128234A (en) | Experimental provision and the method for Young's modulus is surveyed by the beam deflection method of simple harmonic oscillation | |
| CN106053265A (en) | Experiment device and method for measuring Young modulus of metal wire according to resonance | |
| CN105954361A (en) | Experimental device and method for measuring Young modulus by virtue of beam bending method according to resonance principle | |
| CN106018556A (en) | Simple harmonic oscillation based experimental device and method for measuring Young's modulus with beam bending method | |
| CN106198748A (en) | The beam deflection method using resonance principle surveys experimental provision and the method for Young's modulus | |
| CN106248501A (en) | Experimental provision and the method for Young's modulus is surveyed according to the beam deflection method of resonance principle | |
| CN106053606A (en) | Experiment device and method adopting resonance principle to measure Young modulus of metal wire | |
| CN106226165A (en) | Beam deflection method according to simple harmonic oscillation surveys experimental provision and the method for Young's modulus | |
| CN106053604A (en) | Experiment device and method utilizing resonance principle to measure Young modulus of metal wire | |
| CN208313903U (en) | A kind of device measuring chopped strand elasticity modulus | |
| CN106248500A (en) | The beam deflection method utilizing covibration surveys experimental provision and the method for Young's modulus | |
| CN106092747A (en) | Experimental provision and the method for Young's modulus is surveyed according to the beam deflection method of simple harmonic oscillation | |
| CN106053267A (en) | Experiment device and method adopting resonance vibration to measure Young modulus of metal wire | |
| CN106908096B (en) | Ultralow frequency simple harmonic oscillation displacement and stretch bending composite strain comprehensive test device | |
| CN105788413A (en) | Experimental device and method for measuring Young's modulus of metal wire based on resonance principle | |
| CN106092789A (en) | The beam deflection method using simple harmonic oscillation surveys experimental provision and the method for Young's modulus | |
| Pradhan et al. | Determination of Young’s modulus by studying the flexural vibrations of a bar: experimental and theoretical approaches | |
| CN210639826U (en) | Multifunctional physical experiment teaching aid |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20161012 |
|
| WD01 | Invention patent application deemed withdrawn after publication |