CN101206166A - Method for establishing relationship of displacement and influence value of digital display rebound tester sensor based on motion equation - Google Patents

Abstract

The invention establishes a numerical relation between a sensor induction value and a displacement value of a digital display resiliometer according to the motion equation of impacting a slider when the resiliometer (including mortar resiliometer, common resiliometer and etc.) rebounds. The method does not depend on the space linearity of the sensor. The key points of the technical proposal are as follows: the invention establishes the motion equation (see formula (1)) of an impacting hammer in a rebounding stage when the resiliometer is working, a formula (2) or a formula (3) can also be obtained through conversion; Beta and Omega are decided by the self features of the resiliometer, and I is decided together by a rebounding direction and the self features of the resiliometer; if the rebounding direction is determined, L is decided by the self features of the resiliometer. T represents the time when a rebounding position is reached, X represents the displacement value when a highest rebounding position is reached, and a zero-time reference is the time when the impacting hammer drives the sensor (or part of the sensor) to move. L can be obtained through experiment and calculation. According to the formula (2) or (3), the relation between the displacement value xI and the time ti can be established, an apparatus obtains the sensor induction value ri at each ti, and thus the relation between ri and xi can be established.

Description

Set up the displacement and the influence value relation of digital display reisilometer sensor based on the equation of motion

Technical field

The digital display reisilometer is to go up the rigging position sensor at common reisilometer (comprising the not automatic all kinds of reisilometers of gathering the rebound value device of installation such as mortar reisilometer, high-strength reisilometer) to obtain rebound value automatically.Be widely used in the intensity detection of mixing earth and other structures, member and material.

Background technology

The displacement transducer of some digital display reisilometer need be set up the corresponding relation (such as the correspondence table of sensed values and shift value or equation) between a shift value and the sensor sensing value in advance.During reisilometer work,, after the acquisition sensor sensing value, obtain the shift value corresponding, can obtain rebound value with it by calculating or enquiry form according to this relation.Along with the increase of working sensor number of times, the prolongation of time, the corresponding relation between shift value and the sensor sensing value may change, and need rebulid this corresponding relation.

Summary of the invention

Elastic hammer drove the equation of motion of sensor (or its part) when the present invention worked according to reisilometer, provided the method for setting up shift value and sensor sensing value corresponding relation.

Reisilometer when work elastic hammer drives sensor (or its part) motion, and to the time interval of maximum displacement value (being the rebound value position), its equation of motion is in moment of sensor (or its part) setting in motion (be called among the present invention timing zero point):

y＝Ae ^-βtcos(ωt+).....................................................(1)

Make y=x+l, the displacement that x begins for timing zero point, l is a reisilometer when working on certain orientation, the equilibrium position is to the distance of contact position.Being described as follows of equilibrium position and contact position, this explanation is useful for patent of the present invention.

The equilibrium position: the thrum hammer under the acting in conjunction of gravity own, spring tension or anchorage force, indicator slide block gravity, indicator slide block friction force, the residing position of elastic hammer.Because the restriction in reisilometer space, elastic hammer in fact not necessarily can be in this position.Indicator slide block gravity and indicator slide block friction force were not added on the elastic hammer before timing zero point, influenced but value is subjected to their.

Contact position: in the thrum hammer springback process, touch the indicator slide block shell fragment, the initial time that the push pointer slide block moves together, the residing position of elastic hammer.

β and ω are the characteristic quantities of reisilometer itself, and l is determined jointly by attack direction and the feature of reisilometer own, if the attack direction determines that then l is also by the characteristics determined of reisilometer own.For the reisilometer of certain kind, compliant standard, β and ω are definite values, and on given attack direction, l also is a definite value.Equation is transformed to:

x+l＝Ae ^-βtcos(ωt+).........................................(2)

T=T, x=X are arranged when arriving the rebound value position:

ωT+＝π.......................................................(3)

{。##.##1},

＝π-ωT.......................................................(4)

At timing zero point, t=0, x=0, following equation:

l＝Ae ^-β×0cos(ω×0+)＝Acos...............................(5)

Like this, the relation of time and displacement provides by following formula:

$x+l=\frac{l}{\cos (\mathrm{\π}-\mathrm{\ωT})}{e}^{-\mathrm{\βt}}\cos (\mathrm{\ωt}+\mathrm{\π}-\mathrm{\ωT})...\left(7\right)$

$x=\frac{l}{\cos (\mathrm{\π}-\mathrm{\ωT})}{e}^{-\mathrm{\βt}}\cos (\mathrm{\ωt}+\mathrm{\π}-\mathrm{\ωT})-l...\left(8\right)$

This relation shows, by attack, according to the equation of motion just can Time Created displacement relation, and the relation between time and the sensor sensing value can be set up by sampling, like this, the relation between displacement and the sensor sensing value just can be set up.As seen from the above analysis, this scaling method does not rely on the linearity on the sensor spatial sense.

Also can utilize when arriving maximum position has t=T, and x=X (X obtains by eye reading) determines l, and this method can not arranged the attack direction, sets up the relation between shift value and the influence value under the prior situation that does not preset the l value.

X+l＝Ae ^-βTcos(ωT+)＝Ae ^-βTcosπ.....................(9)

l＝-X/(1+e ^-βT/cos(π-ωT)).............................(11)

(11) formula substitution (8) formula, any in the attack direction, do not preset under the situation of l value in advance, can set up the corresponding relation between shift value and the influence value.

x＝-X(e ^-βtcos(ωt+π-ωT)/cos(π-ωT)-1)/(1+e ^-βT/cos(π-ωT)).......(12)

L on the various types of reisilometer all directions also can calculate by the following method.

When being in the equilibrium position, elastic hammer has:

(m ₁g+m ₂g+m ₃g)cosθ+f＝KΔl ₁...........................(13)

K is the elastic modulus of spring of linking to each other with elastic hammer, m ₁Be the quality of elastic hammer, m ₂Be the Equivalent Mass of Spring that links to each other with elastic hammer, m ₃Be the quality of indicator slide block, θ is the attack direction and the angle of direction straight down, and f comprises that indicator slide block is with guide rod and the summation of the friction force of the friction force between slotting.

Spring does not have distortion, and elastic hammer is l from the distance of contact position ₁Then have

l＝l ₁+Δl ₁..................................................(14)

Embodiment

By test and calculating, obtain the β and the ω value of the reisilometer of various types of compliant standard, and the l value on all directions.

Reisilometer work, the elastic hammer take-off, when driving sensor (or its part) motion, each is worth t constantly instrument record _iWith its corresponding sensor influence value r _i, according to equation (8) or (12), set up displacement x then _iWith time t _iRelation, so just can set up r _iAnd x _iRelation.The method that the present invention provides does not rely on the linearity on the sensor spatial sense.

Claims (6)

1. the equation of motion that elastic hammer drove sensor (or its part) in the resilience stage when reisilometer was worked is:

x+l＝Ae ^-βtcos(ωt+)...........................................(1)

It is time zero t=0 that elastic hammer touches the initial moment that sensor (or its part) drives its motion, and x=0 has following relation:

l＝Acos()........................................................(2)

When arriving the rebound value position, t=T, x=X have following relation:

ω T+ =π is =π-ω T.......................................... (3)

X+l＝Ae ^-βTcos(ωT+)＝-Ae ^-βT................................(4)

Simultaneous (2) and (3) obtain following relation:

$A=\frac{l}{\cos (\mathrm{\π}-\mathrm{\ωT})}...\left(5\right)$

Simultaneous (1), (3) and (5) obtain following relation:

$x=\frac{l}{\cos (\mathrm{\π}-\mathrm{\ωT})}{e}^{-\mathrm{\βt}}\cos (\mathrm{\ωt}+\mathrm{\π}-\mathrm{\ωT})-l...\left(6\right)$

Simultaneous (4) and (5) get following relation:

l＝-X(e ^-βT/cos(π-ωT)+1) ^-1......................................(7)

(7) substitution (6)

x＝-X(e ^-βtcos(ωt+π-ωT)/cos(π-ωT)-1)/(1+e ^-βT/cos(π-ωT)).......(8)

β and ω are by the characteristics determined of reisilometer own, reisilometer for certain kind, compliant standard, β and ω are definite values, can and calculate by test, X is the maximum displacement of sensor (or its part), T is a rebound value position time corresponding, and time zero is that elastic hammer touches the initial moment that sensor (or its part) drives its motion.Can set up shift value x by equation (6) or (8) _iWith moment t _iRelation, at each t constantly _i, instrument obtains sensor sensing value r _i, so just can set up r _iAnd x _iRelation.

2.l determine jointly by attack direction and the feature of reisilometer own, if the attack direction determines that then l is by the characteristics determined of reisilometer own.On certain attack direction, l is a definite value.Can obtain the l value of reisilometer on all directions various types of, the compliant standard by test calculating.

3. also can be after attack, the X value of this attack is imported in eye reading, calculates the l value by formula (7), and this is need not arrange the attack direction.

4. obtain the l value by claim 3, measure the angle value corresponding, like this, can obtain the l value of various reisilometer all directions with it.

5. for the spring system of reisilometer, following formula is arranged:

(m ₁g+m ₂g+m ₃g)cosθ+f＝KΔl ₁............................(9)

K is the elastic modulus of spring of linking to each other with elastic hammer, m ₁Be the quality of elastic hammer, m ₂Be the Equivalent Mass of Spring that links to each other with elastic hammer, m ₃Be the quality of indicator slide block, θ is the attack direction and the angle of direction straight down, when f drives the indicator slide block motion for the attack piece, comprise indicator slide block and guide rod and slot between the summation of friction force of friction force.When if spring does not have distortion, elastic hammer is l from the distance of contact position ₁, then have

l＝l ₁+Δl ₁..................................................(10)

6. do not needing to know under the situation of l, can set up shift value x according to formula (8) _iWith moment t _iRelation, at each t constantly _i, instrument obtains sensor sensing value r _i, so just can set up r _iAnd x _iRelation