CN205642279U - Detection device who meets an emergency suitable for concrete - Google Patents

Abstract

The utility model relates to a strain detection field especially relates to a detection device who meets an emergency suitable for concrete. The device includes: a metal soleplate bonds on the detection position of concrete, a strain sensor, the fixed setting in metal soleplate's center, wherein, strain sensor includes: have four resistance strain gauge's perpendicular to each other wheatstone bridge, wherein, it has the buffer layer to fill up between two resistance strain gauge and the metal soleplate.

Description

A kind of detection device of the strain being applicable to concrete

Technical field

This utility model relates to strain detecting field, particularly relate to a kind of be applicable to concrete should The detection device become.

Background technology

It is existing for the detection method of the strain of the Inhomogeneous wave fields such as concrete would generally be adopted Detect with strain transducer, due to by temperature, the non-homogeneity etc. of object under test material The impact of factor, there is null offset in the detected value of strain transducer, the problem that error is big, nothing Method ensures the accuracy of the strain value of detection.

Utility model content

The problem existed for prior art, now provides the inspection of a kind of strain being applicable to concrete Survey device and method, it is possible to the Inhomogeneous wave fields such as concrete are carried out the detection of STRESS VARIATION.

Concrete technical scheme is as follows:

The detection device of a kind of strain being applicable to concrete, is applied to the inspection of the strain to concrete Surveying, described detection device includes:

One metal base plate, is adhered on the detection position of described concrete；

One strain transducer, is fixedly installed on the center of described metal base plate, wherein,

Described strain transducer includes:

There is the Wheatstone bridge of four resistance strain gages perpendicular to each other, wherein, described in two It is lined with cushion between resistance strain gage and described metal base plate.

Preferably, described metal base plate be shaped as square.

Preferably, the resistance of four described resistance strain gages is identical.

Preferably, the material of described cushion is thermally conductive grease.

Preferably, two resistance strain gages being lined with described cushion are two on a pair linea angulata Described resistance strain gage.

Preferably, the material of described metal base plate is aluminium alloy.

Preferably, value ε of described STRESS VARIATION is:Wherein,

△ U is the changing value of Wheatstone bridge output voltage；K is the spirit of described resistance strain gage Quick coefficient；E is the running voltage of Wheatstone bridge.

Preferably, described strain transducer upper surface is coated with a waterproof layer.

Preferably, the material of described waterproof layer is silica gel.

A kind of detection method of the strain being applicable to concrete, including:

One metal base plate being fixedly installed strain transducer, wherein, strain transducer bag are provided Include: having the Wheatstone bridge of four resistance strain gages perpendicular to each other, two described resistance should Become and be lined with cushion between sheet and described metal base plate；

Metal base plate described in one is adhered on concrete to be measured；

Detect the changing value of the output voltage of described Wheatstone bridge, according to described output voltage Changing value calculates the value of the STRESS VARIATION of described concrete.

Technique scheme provides the benefit that:

In technique scheme by by two of which resistance strain gage in Wheatstone bridge with mixed Between solidifying soil, the sensing of strain is cut off so that it is cannot experience STRESS VARIATION, to improve wheatstone The sensitivity of electric bridge, and then improve the accuracy of STRESS VARIATION.

Accompanying drawing explanation

Fig. 1 is that the structure of the embodiment of the detection device of a kind of STRESS VARIATION of this utility model is shown It is intended to；

Fig. 2 is the circuit connection diagram of the embodiment of this utility model Wheatstone bridge；

Fig. 3 is the flow chart of the embodiment of the detection method of a kind of STRESS VARIATION of this utility model.

Detailed description of the invention

It should be noted that in the case of not conflicting, following technical proposals, technical characteristic it Between can be mutually combined.

Below in conjunction with the accompanying drawings detailed description of the invention of the present utility model is further described:

As it is shown in figure 1, present embodiments provide a kind of Inhomogeneous wave fields such as concrete of being applicable to Strain-Sensing device, is applied to the detection to concrete, and detection device includes:

One metal base plate, uses binding agent to be adhered on the detection position of concrete；

One strain transducer, is fixedly installed on the center of metal base plate, wherein,

Strain transducer includes:

There is the Wheatstone bridge of four resistance strain gages perpendicular to each other, wherein, two resistance Cushion it is lined with between foil gauge and metal base plate.

Two therein are delayed between resistance strain gage and metal base plate by the present embodiment by one Rush layer isolation so that two resistance strain gages of isolation cannot experience the change of stress to improve The sensitivity of Wheatstone bridge, simultaneously because variations in temperature can be compensated by Wheatstone bridge, Use technique scheme that the Inhomogeneous wave fields such as concrete can carry out the detection of STRESS VARIATION, Overcome the impact of temperature drift, can detect for a long time.

In one preferred embodiment of this utility model, metal base plate be shaped as square.

Concrete is a kind of mixture being made up of rubble and mortar, rubble and the springform of mortar Amount is not quite similar, and the stress distribution on its surface is complicated, uneven due to concrete surface strain Property, the present embodiment uses foursquare metal base plate to be adhered to concrete surface and forms one.Mixed The strain on solidifying soil surface can cause metal base plate to produce strain.Metal base plate has certain rigidity, The strain at the centre of surface position of metal base plate reflects the concrete region that this metal base plate covers The meansigma methods of the strain in territory, overcomes rectangular base plate sensing concrete stress change vertical and horizontal The error that inhomogeneities causes.

Further, metal base plate is 3 to 5 times that the length of side is more than concrete crushed stone maximum gauge, Thickness is the square-shaped metal base plate of 2 millimeters, not only overcomes the uneven of concrete NDT direction Property, and overcome the error that horizontal inhomogeneities causes.

In one preferred embodiment of this utility model, the resistance of four resistance strain gages is identical.

In one preferred embodiment of this utility model, the material of cushion is thermally conductive grease.

In one preferred embodiment of this utility model, it is lined with two resistance strain gages of cushion It is two resistance strain gages on a pair linea angulata.

As in figure 2 it is shown, the strain transducer of the present embodiment is should by 4 identical resistance Become the Wheatstone bridge of sheet composition.Wherein, 4 identical resistance strain gages, two is biphase Mutually vertical, respectively resistance strain gage R1, resistance strain gage R2, resistance strain gage R3, Resistance strain gage R4.Wherein resistance strain gage R1 and resistance strain gage R3 is directly adhered to gold Belong to base plate.Resistance strain gage R2, resistance strain gage R4 thermally conductive grease are pasted on metal bottom Plate.

In one preferred embodiment of this utility model, the material of metal base plate is aluminium alloy.

In the present embodiment, aluminum alloy bottom plate has good heat conductivity, the temperature of aluminum alloy bottom plate When changing, 4 resistor discs being pasted on aluminum alloy bottom plate can synchronize identical temperature Degree change, just can automatically eliminate the drift of the datum mark that this variations in temperature causes by Wheatstone bridge Move.

In one preferred embodiment of this utility model, value ε of STRESS VARIATION is:Its In,

△ U is the changing value of Wheatstone bridge output voltage；K is the sensitive system of resistance strain gage Number；E is the running voltage of Wheatstone bridge.

In the present embodiment, in Fig. 2, have according to bridge balance formula:

$\mathrm{\Δ}U=\[\frac{R1\·R2}{{(R1+R2)}^2}*(\frac{\mathrm{\Δ}R1+Rt}{R1}-\frac{\mathrm{\Δ}R2+Rt}{R2})+\frac{R3\·R4}{{(R3+R4)}^2}*(\frac{\mathrm{\Δ}R3+Rt}{R3}-\frac{\mathrm{\Δ}R4+Rt}{R4})\]*E;$

Wherein, △ R1 is the changing value affecting resistance strain gage R1 strained, and △ R2 is The changing value affecting resistance strain gage R2 strained, △ R3 is strained to affect resistance The changing value of foil gauge R3, △ R4 is the changing value affecting resistance strain gage R4 strained, Rt is the situation of change being affected resistance strain gage resistance by temperature.

Due to, the resistance of four resistance strain gages is identical, i.e. R1=R2=R3=R4=R, Then above formula can be reduced to:

$\mathrm{\Δ}U=\[\frac{R^2}{4R^2}*\left(\frac{\mathrm{\Δ}R1+Rt-\mathrm{\Δ}R2-Rt}{R}\right)+\frac{R^2}{4R^2}*\left(\frac{\mathrm{\Δ}R3+Rt-\mathrm{\Δ}R4-Rt}{R}\right)\]*E;$

Simplify above formula further:

$\mathrm{\Δ}U=\[\frac{1}{4}*\left(\frac{\mathrm{\Δ}R1-\mathrm{\Δ}R2}{R}\right)+\frac{1}{4}*\left(\frac{\mathrm{\Δ}R3-\mathrm{\Δ}R4}{R}\right)\]*E;$

Then affected resistance variations Rt produced to be eliminated by variations in temperature, i.e. strain sensing Device is not by variations in temperature, and Wheatstone bridge can carry out temperature-compensating.Owing to strain transducer is subject to Unidirectional strain, resistance strain gage R2, R4 will not be stressed the impact of change, then Δ R4= Δ R2=0, Δ R1=Δ R3=Δ R, above formula can be changed into:

$\mathrm{\Δ}U=\[\frac{1}{4}*\left(\frac{\mathrm{\Δ}R}{R}\right)+\frac{1}{4}*\left(\frac{\mathrm{\Δ}R}{R}\right)\]*E$

Simplify above formula further:

$\mathrm{\Δ}U=\frac{\mathrm{\Δ}R}{2R}*E;$

According to resistance variations and the sensitivity coefficient K of resistance strain gage and the relation of strain stress, have Equation below:

$K=\frac{\mathrm{\Δ}R}{R}*\frac{1}{\mathrm{\ϵ}};$

Obtained by the value of STRESS VARIATION is substituted into formula:

$\mathrm{\ϵ}=\frac{2*\mathrm{\Δ}U}{E*K}$

Knowable to above-mentioned formula, will by two resistance sensing STRESS VARIATION of minimizing in the present embodiment The value of sensitivity coefficient more precision and also do not affect the temperature of Wheatstone bridge in the present embodiment Degree compensates.

In one preferred embodiment of this utility model, strain transducer upper surface is coated with one to be prevented Water layer.

In one preferred embodiment of this utility model, the material of waterproof layer is silica gel.

Foil gauge surface covers silica gel and carries out water-proofing treatment, it is possible to pair of strain sensors carries out waterproof Protection, improves the precision of strain detecting.

The present embodiment also provides for giving the detection method of a kind of STRESS VARIATION, as it is shown on figure 3, bag Include:

One metal base plate being fixedly installed strain transducer, wherein, strain transducer bag are provided Include: there are the Wheatstone bridge of four resistance strain gages perpendicular to each other, two resistance strain gages And it is lined with cushion between metal base plate；

One metal base plate is adhered on concrete to be measured；

The changing value of the output voltage of detection Wheatstone bridge, according to the changing value meter of output voltage Calculate the value of the STRESS VARIATION of concrete.

To sum up, by by two of which resistance strain gage in Wheatstone bridge in technique scheme And between concrete, the sensing of strain is cut off so that it is cannot experience the change of stress, to improve The sensitivity of Wheatstone bridge, and then improve the accuracy of STRESS VARIATION.

By explanation and accompanying drawing, give the exemplary embodiments of the ad hoc structure of detailed description of the invention, Based on this utility model spirit, other conversion also can be made.Although above-mentioned utility model proposes Existing preferred embodiment, but, these contents are not intended as limitation.

For a person skilled in the art, after reading described above, various changes and modifications Will be apparent to undoubtedly.Therefore, appending claims should be regarded as and contains this utility model True intention and whole variations and modifications of scope.Any and institute in Claims scope There are scope and the content of equivalence, are all considered as still belonging in intention of the present utility model and scope.

Claims (9)

1. the detection device of the strain being applicable to concrete, it is characterised in that it is right to be applied to The strain detecting of concrete, described detection device includes:

One metal base plate, is adhered on the detection position of described concrete；

One strain transducer, is fixedly installed on the center of described metal base plate, wherein,

Described strain transducer includes:

There is the Wheatstone bridge of four resistance strain gages perpendicular to each other, wherein, described in two It is lined with cushion between resistance strain gage and described metal base plate.

The detection device of the strain being applicable to concrete the most according to claim 1, it is special Levy and be, described metal base plate be shaped as square.

The detection device of the strain being applicable to concrete the most according to claim 1, it is special Levying and be, the resistance of four described resistance strain gages is identical.

The detection device of the strain being applicable to concrete the most according to claim 1, it is special Levying and be, the material of described cushion is thermally conductive grease.

The detection device of the strain being applicable to concrete the most according to claim 1, it is special Levying and be, two resistance strain gages being lined with described cushion are described in two on a pair linea angulata Resistance strain gage.

The detection device of the strain being applicable to concrete the most according to claim 1, it is special Levying and be, the material of described metal base plate is aluminium alloy.

The detection device of the strain being applicable to concrete the most according to claim 3, it is special Levying and be, value ε of described STRESS VARIATION is:Wherein,

△ U is the changing value of Wheatstone bridge output voltage；K is the spirit of described resistance strain gage Quick coefficient；E is the running voltage of Wheatstone bridge.

The detection device of the strain being applicable to concrete the most according to claim 1, it is special Levying and be, described strain transducer upper surface is coated with a waterproof layer.

The detection device of the strain being applicable to concrete the most according to claim 8, it is special Levying and be, the material of described waterproof layer is silica gel.