CN103453832A - Multipurpose deformation measuring device and measuring method - Google Patents

Abstract

The invention discloses a multipurpose deformation measuring device and a measuring method of the device, belonging to the technical field of engineering testing. The measuring device of the present invention comprises a pillar, a beam, a cantilever beam, a rotating rod, a first flexible cable, a second flexible cable, a first fixed snap ring, a second fixed snap ring, a vernier scale, a resistance strain gauge, and a bridge box. The rear end of the strain gauge is placed, and the front end is pulled by a flexible cable to transmit deformation, so that the measuring device can be adapted to the measurement of large gauge specimens and extreme environments under liquid; Select the pin hole of the rotating rod for the modulus of elasticity, assemble the first and second fixed snap rings with the vernier scale and fix them on the test piece, then assemble the first and second flexible cables, start the test bench to apply load, and read the bridge signal, calculate the deflection of the cantilever beam, and obtain the deformation of the tested part. The invention has simple structure, is applicable to the measurement of large gauge distance, compression deformation and extreme environment under liquid, and has wide application.

Description

A multi-purpose deformation measuring device and measuring method

technical field

The invention belongs to the technical field of engineering testing, and relates to a measurement of solid deformation, in particular to a measuring device and a measuring method for engineering structure or sample tension and compression deformation.

Background technique

In engineering testing practice, it is very important to accurately measure the deformation of material samples or structures after being stressed. For example, in the tensile test of materials, when we determine the elastic modulus of the material, specify the non-proportional yield strength, or draw the stress-strain curve, we must accurately measure the deformation of the sample of the material after tension, compression The same goes for experiments. At present, the deformation in this kind of test is generally measured by the extensometer. The output signal of the commonly used resistance strain extensometer is an electrical signal, which is convenient for the automatic collection and processing of the instrument. It is currently the most widely used, but the disadvantages are also obvious: 1. Usually the standard The distance is fixed, in order to meet the needs of different tests, extensometers with various gauge lengths must be equipped, and the test cost increases; 2. The measuring range is small, only small deformation can be measured, and it is not suitable for larger deformation measurement; 3. Since the extensometer passes through the blade It is directly connected to the sample, and the large impact force generated when the sample breaks will be directly transmitted to the sensitive element of the extensometer, which will damage the measuring mechanism; 4. It is not suitable for compression deformation; 5. It cannot meet the requirements of underwater, especially high temperature underwater , Corrosive environment test.

Existing foreign extensometers for water can be used in water or saline solution, but they are limited to normal temperature and short-term tests, and like conventional extensometers, the gauge length is fixed and the measuring range is also small.

Chinese utility model patent CN2816793Y aims at the problem of the small gauge length of existing extensometers, and discloses a large gauge length extensometer. By adding a deformation transition device between the enlarged gauge length device and the conventional small gauge length extensometer, The deformation equivalent of the large distance device is converted to the deformation of the two blades of the small gauge extensometer, so as to realize the measurement of the large gauge deformation. However, since the measurement body of the device is still a traditional small-gauge extensometer, it is still not suitable for large deformation, compression deformation, and underwater measurement.

Contents of the invention

The object of the present invention is to overcome the problems and deficiencies in the prior art, and provide a deformation measuring device and a measuring method which are convenient, fast, low in cost and applicable to various purposes.

In order to achieve the above purpose, the technical solution adopted to solve the above technical problems is a multi-purpose deformation measuring device, including a pillar 7 with a base at the lower end, a beam 21 with a through hole deviated from the center line, and multiple radial The rotating rod 5 of the pin hole, the cantilever beam 6, the first flexible cable 3, the second flexible cable 4, the first fixed snap ring 1, the second fixed snap ring 2 and the vernier scale 18, wherein the upper and lower ends of the pillar 7 are respectively There is a radial through hole, and the crossbeam 21 is fixedly sleeved above the middle part of the pillar 7 through the through hole. The left end of the crossbeam 21 is vertically connected with one end of the cantilever beam 6, and the right end of the crossbeam 21 is connected with the cantilever beam 6. Any pin hole in the middle of the rotating rod 5 is pinned, one end of the first flexible cable 3 is connected to the upper end of the rotating rod 5, and the other end passes through the through hole at the upper end of the pillar 7 and the second fixed snap ring 2 in turn. It is connected with the first fixed snap ring 1, one end of the second flexible cable 4 is connected with the lower end of the rotating rod 5, and the other end is connected with the other end of the cantilever beam 6 through the through hole at the lower end of the pillar 7. connected, the first fixed snap ring 1 and the second fixed snap ring 2 are also respectively connected with the vernier 18 close to the test piece 20, and the upper surface of the left end of the beam 21 is also provided with a The bridge box 9 is electrically connected to the strain gauge 10 on the upper part of the beam 6 .

The first fixed snap ring 1 and the second fixed snap ring 2 are all designed as scissor-shaped spring clips, which include two cross-connected clip bodies and a clamping spring that generates a clamping force. The clip body is composed of a chuck and a clamp handle , the chucks are provided with concave clamping blades on the opposite inner side, and a protruding handle is provided on the outer middle, the connection position is located in the clamping handle section, and it has a through hole for the first flexible cable 3 to pass through, and the clamping The spring is connected to the inner side of the two clamping handles near the end of the collet.

As a further improvement of the device of the present invention, a measuring device that can be used to measure compression deformation is provided. For this reason, the first fixed snap ring 1 and the second fixed snap ring 2 are also movably connected with a device for reverse transmission of the tested object. The reverse mechanism 17 of the deformation direction of 20 transmits the stress and deformation of the tested piece 20 in reverse. The reverse mechanism 17 is composed of a sleeve rod and a sleeve. The sleeve is put through the middle part of the sleeve rod. The top and bottom ends of the sleeve rod and the sleeve are radially provided with protrusions in opposite directions, wherein the top end of the sleeve rod and the protrusions at the bottom of the sleeve are respectively provided with central blind holes connected with the second fixed snap ring 2 and the outer lugs of the first fixed snap ring 1, and the protrusions at the bottom of the sleeve rod and the top of the sleeve are opened for The radial through hole of the first flexible cable 3 is passed through.

In addition, a return spring 8 is provided between any angle formed between the rotating rod 5 and the crossbeam 21 of the device of the present invention to reset the cantilever beam 6 . The material of the base of the pillar 7 is a magnetic material, which is convenient for quick placement of the device on site. The first flexible cable 3 and the second flexible cable 4 are preferably made of Invar alloy material, which has a coefficient of expansion close to zero, a large modulus of elasticity, high tensile rigidity, and a length that does not change with temperature.

In order to achieve the above object, another technical solution adopted by the present invention to solve the technical problem is: a measurement method of a multipurpose deformation measuring device, comprising the following steps:

1) Check and fix the gauge length of the vernier ruler 18, and select the pin hole position of the rotating rod 5 and the beam 21 according to the material of the test piece 20 on the side;

2) The vernier ruler 18 is connected with the first fixed snap ring 1 and the second fixed snap ring 2, and the first fixed snap ring 1 and the second fixed snap ring 2 are clamped on the tested object 20; The flexible cable 4 passes through the through hole at the lower end of the pillar 7, and the two ends are tensioned and respectively fixed to the lower end of the cantilever beam 6 and the lower end of the rotating rod 5; Through the through hole at the upper end of the pillar 7, the second fixed snap ring 2, tensioned and connected with the first fixed snap ring 1;

3) Using the Wheatstone bridge principle, the bridge box 9 and the strain rosette 10 on the upper part of the cantilever beam 6 are used to form a measuring bridge according to the full bridge method;

4) Start the testing machine, apply a load to the test piece 20, the test piece 20 is deformed, and then the cantilever beam 6 is pulled to produce bending deformation, thereby driving the resistance strain gauge 10 to deform and causing its resistance value to change, so that the measuring bridge Output voltage signal ΔU;

5) Use the data acquisition system of the testing machine to read the voltage signal ΔU output by the bridge box 9, and obtain the linear strain ε of the cantilever beam 6 at the resistance strain gauge 10 along the length direction of the cantilever beam 6 according to the electrical stress and strain test method; substitute it into Hu Ke The law obtains the bending normal stress σ at this place; then according to the bending normal stress formula, the bending moment M of the section where the resistance strain gauge 10 on the cantilever beam 6 is obtained; the bending moment M is divided by the section where the resistance strain gauge 10 of the upper part of the cantilever beam 6 is The distance at the lower end of the cantilever beam 6 obtains the concentrated force P received by the lower end of the cantilever beam 6, and the resulting concentrated force P value is substituted into the bending deflection formula to obtain the deflection δ produced at the lower end of the cantilever beam 6;

6) Separate the length ratio of the upper and lower parts of the rotating rod 5 according to the position of the pin hole of the rotating rod 5, determine the linear proportional coefficient k between the deflection δ of the lower end of the cantilever beam 6 and the deformation of the tested piece 20, and multiply the coefficient k by the length of the cantilever beam 6 Deflection δ, so as to obtain the deformation amount of the tested piece 20.

In summary, compared with the prior art, the present invention has the following characteristics and beneficial effects:

1. Since the rear end of the strain gauge is placed, the front end is pulled by the flexible cable to transmit deformation, so that the measuring device can adapt to the measurement of large gauge specimens and extreme underwater environments;

2. Through the adjustment of the pin hole on the rotating rod, the test piece with a large elastic modulus can be measured;

3. By introducing a flexible cable between the blade and the strain gauge, the impact generated when the sample is measured and broken can be gradually attenuated, avoiding the need to remove the traditional extensometer in advance based on experience in the later stage of measurement, otherwise the impact will damage the extensometer. Disadvantages;

4. After installing the reverse mechanism, the measurement of compression deformation is added. The invention has simple structure, convenient operation and wide application;

5. By adjusting the opening distance of the vernier, it can meet the needs of different sizes of test pieces.

Description of drawings

Fig. 1 is the structural representation of measuring device of the present invention;

Fig. 2 is a structural schematic diagram of the fixing snap ring of the present invention;

Figure 3 is a partial schematic diagram of the deformation measurement of the tested piece in the underwater environment;

Fig. 4 is a structural schematic diagram of the reverse mechanism of the present invention;

Fig. 5 is a schematic diagram of the working stroke of the device of the present invention.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Fig. 1 is the structural representation of the preferred embodiment of the measuring device of the present invention, as shown in Fig. 1, the device of the present invention comprises the pillar 7 with base at the lower end, deviates from the midline and has a crossbeam 21 with a through hole, evenly distributed with a plurality of radial The rotating rod 5 of the pin hole, the cantilever beam 6, the first flexible cable 3, the second flexible cable 4, the first fixed snap ring 1, the second fixed snap ring 2 and the vernier scale 18, wherein the upper and lower ends of the pillar 7 are respectively There is a radial through hole, and the crossbeam 21 is fixedly sleeved above the middle part of the pillar 7 through the through hole. The left end of the crossbeam 21 is vertically connected with one end of the cantilever beam 6, and the right end of the crossbeam 21 is connected with the cantilever beam 6. Any pin hole in the middle part of the rotating rod 5 is pinned, and the rotating rod 5 has 8 pin holes to meet the measurement needs. The beam 21 adopts a material with a large bending stiffness, and the cantilever beam 6 adopts a material with a small bending stiffness. One end of the first flexible cable 3 is connected to the upper end of the rotating rod 5, and the other end passes through the through hole at the upper end of the pillar 7 in turn, and the second fixed snap ring 2 is connected with the first fixed snap ring 1, so that One end of the second flexible cable 4 is connected to the lower end of the rotating rod 5, and the other end is connected to the other end of the cantilever beam 6 through the through hole at the lower end of the pillar 7. The second fixed snap ring 2 is also respectively connected with the vernier 18 close to the test piece 20, and the upper surface of the left end of the crossbeam 21 is also provided with a bridge box 9, and is arranged on the resistance strain gauge on the top of the cantilever beam 6. 10 connections form the Wheatstone measuring bridge.

The setting of the first fixed snap ring 1 and the second fixed snap ring 2 is used to transmit the deformation of the tested piece 20, and various methods can be adopted, as long as one end of the first flexible cable 3 is fixed to the tested piece, the other end can be pulled when being pulled. Ensure that the first flexible cable 3 moves freely. In this example, the first fixed snap ring 1 and the second fixed snap ring 2 are designed as scissor-shaped spring clips, as shown in Figure 2, which include two cross-hinged clip bodies And the clamping spring that generates the clamping force. The clamp body is composed of a collet and a clamp handle. The clamping head is equipped with a concave clamping edge on the opposite side, and a protruding handle is provided in the middle of the outer side. The hinge position is located in the clamp handle section. , and a through hole is opened at the hinged position for the flexible cable 3 to pass through and move, and the clamping spring is connected to the inner side of the two clamping handles near the end of the chuck. The vernier scale 18 is designed with two concave holes matched with the protruding handles on the outside of the chuck, so as to realize the connection with the first fixing snap ring 1 and the second fixing snap ring 2 through the insertion of the concave holes and the protruding handles. The concave clamping blade increases the contact points when clamping the test piece 20, thereby eliminating the problem of stress concentration at the contact portion of the traditional extensometer blade.

In addition, a return spring 8 is set between the angles formed by the rotating rod 5 and the crossbeam 21 of the device of the present invention to reset the cantilever beam 6 and facilitate the tension of the first flexible cable 3 and the second flexible cable 4 during measurement. Tight and install. The base of the pillar 7 is made of magnetic material, which can be fixed with the metal workbench by its own magnetism, and can be quickly placed on site. The first flexible cable 3 and the second flexible cable 4 are preferably made of Invar alloy material, which has a coefficient of expansion close to zero, a large modulus of elasticity, high tensile rigidity, and a length that does not change with temperature.

During the test, the upper end of the tested piece 20 is fixed to the fixed beam of the testing machine, and the lower end is fixed to the movable beam of the testing machine. The loading of the tested piece 20 is realized through the movement of the movable beam, and the tested piece 20 is deformed under the load and pulled. The first flexible cable 3, the rotating rod 5, and the second flexible cable 4 make the cantilever beam 6 deflect, so that the deformation of the tested piece can be finally obtained.

The difference between the second embodiment of the device of the present invention and the previous embodiment is mainly the change of the application environment. Fig. 3 shows a partial schematic diagram of the deformation measurement device under the extreme environment under the liquid. The traditional extensometer is not suitable for the submerged environment, especially the extreme submerged environment, such as high temperature and corrosive liquid. The measuring device of the present invention draws out the deformation through pulling transmission, and separates the tested piece from the bridge system. At the same time, the first flexible cable 3 is a corrosion-resistant material that is not sensitive to temperature and can be in direct contact with the corrosive liquid. During measurement, a sleeve can be used to apply a load to the test piece 20, and a rubber ring 14 is used to seal the sleeve and the corrosive liquid container. The device itself The structure and installation are the same as those of the foregoing embodiments, and the flexible cable 3 that is drawn can be guided by the reversing pulley 11 to reversing.

Fig. 4 shows the structure diagram of the reverse mechanism 17 in the third embodiment of the device of the present invention, as a further improvement of the device of the present invention, a kind of measuring device that can be used to measure the compression deformation is provided, for this reason, in the first On the basis of the embodiment, a reverse mechanism 17 is inserted on the first fixed snap ring 1 and the second fixed snap ring 2. The reverse mechanism 17 is mainly composed of a sleeve rod and a sleeve, and is used to place the test piece 20 Stress and deformation are transmitted in reverse, that is, compression becomes expansion, so that the pulling flexible cable 3 is displaced. The sleeve is put through the middle part of the sleeve rod, and the top and bottom ends of the sleeve rod and the sleeve are radially provided with protrusions in opposite directions. 1. The axial central blind hole matched with the outer shank of the second fixed snap ring 2 chuck can be directly plugged in during installation. The bottom of the sleeve rod and the protrusion on the top of the sleeve are provided with radial through holes for the first flexible Cable 3 passes through and fixes. The reverse mechanism 17 passes through the central blind hole of the protrusion at the top of the sleeve rod and the bottom end of the sleeve and the first fixed snap ring 1 and the second fixed snap ring 2 which cooperate with it. The second fixed snap ring 2 is connected, one end of the first flexible cable 3 is connected to the upper end of the rotating rod 5, and the other end passes through the through hole at the upper end of the pillar 7, the through hole of the protrusion on the top of the sleeve and the protrusion at the bottom of the sleeve rod in turn. Things are connected. The rest are the same as the first embodiment. When a compressive load is applied to the tested object 20, the reverse mechanism 17 reversely transmits the displacement direction of the first fixed snap ring 1 and the second fixed snap ring 2, thereby pulling the first flexible cable 3, the rotating rod 5, and the second flexible cable. The cable 4 makes the cantilever beam 6 deflect, and then obtains the deformation of the tested object.

Fig. 5 is the principle diagram of the working stroke of the device of the present invention, the rotating rod 5 is rotated by an angle θ around the point O at the end of the right cantilever under the pulling action of the first flexible cable 3, D'E' is the new position of the rotating rod 5, and the angle γ is the flexible The corresponding rotation angle of cable 3, The angle is the corresponding rotation angle of the flexible cable 4. Assuming that the deformation of the tested piece 20 is ΔL, the displacement of the flexible cable 3 is also ΔL, and there are:

ΔL= _LCD - _LCD′

When the rotation angle θ of the rotating rod 5 is small, the first flexible cable 3 and the second flexible cable 4 rotate the angle γ and is also small, by the law of cosines:

${\mathrm{<span\; class="notranslate">\; L</span>}}_{{\mathrm{<span\; class="notranslate">\; DD</span>}}^{<span\; class="notranslate">\; \&prime;</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="L\; cd"\; filenames="HDA00002186479300021.png,HDA00002186479300031.png"\; state="\{\{state\}\}">L</figure-callout></span><figure-callout\; id="2"\; label="L\; cd"\; filenames="HDA00002186479300021.png,HDA00002186479300031.png"\; state="\{\{state\}\}">\; </figure-callout>}}_{\mathrm{<span\; class="notranslate">\; </span>}}^{\mathrm{<span\; class="notranslate">cd</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{{\mathrm{<span\; class="notranslate">\; cd</span>}}^{<span\; class="notranslate">\; \&prime;</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; cd</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{{\mathrm{<span\; class="notranslate">\; cd</span>}}^{<span\; class="notranslate">\; \&prime;</span>}}\mathrm{<span\; class="notranslate">\; cos</span>}\mathrm{<span\; class="notranslate">\; \&gamma;</span>}$

When the rotation angle γ is small, it is known from the geometric relationship:

γ→0, cos γ≈1

That is:

L _DD' = L _CD - _{L CD'} = ΔL

很小时有：Similarly, corner

Very small with:

L _EE′ =L _GE′ -L _GE

The rotating rod 5 rotates around the O point, and it can be known from the geometric relationship:

$\frac{{\mathrm{<span\; class="notranslate">\; L</span>}}_{{\mathrm{<span\; class="notranslate">\; DD</span>}}^{<span\; class="notranslate">\; \&prime;</span>}}}{{\mathrm{<span\; class="notranslate">\; L</span>}}_{{\mathrm{<span\; class="notranslate">\; EE</span>}}^{<span\; class="notranslate">\; \&prime;</span>}}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; OD</span>}}}{{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; OE</span>}}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; k</span>}$

In the above formula, k is the linear proportional coefficient between the deflection of the cantilever beam 6 and the deformation of the tested piece 20, which can be adjusted by changing the rotation center position O of the rotating rod 5, that is, the position of the pin hole. The above formula expresses the The relationship between the deformation of the test piece 20 and the corner deflection of the cantilever beam 6 .

When utilizing the multi-purpose measuring device of the present invention to measure, at first check and fix the vernier ruler 18 gauge lengths, according to the material of the test piece 20 on the side, select the right cantilever and the hinge pin hole position of the rotating rod 5, when the test piece is metal, etc. For materials with a higher elastic modulus, the pin hole in the upper half of the rotating rod 5 can be selected, and when the test piece is a material with a smaller elastic modulus such as rubber, the pin hole in the lower half of the rotating rod 5 can be selected. The rotational deflection of the cantilever beam 6 is adjusted by the coefficient k.

Then assemble the vernier ruler 18 with the first fixed snap ring 1 and the second fixed snap ring 2 through the concave hole and the convex handle, and clamp the first fixed snap ring 1 and the second fixed snap ring 2 on the tested object 20 The second flexible cable 4 is passed through the lower end of the pillar 7, and the two ends are tensioned and respectively fixed on the lower end of the cantilever beam 6 and the lower end of the rotating rod 5. At this time, the positioning effect of the return spring 8 is convenient for the tensioning of the second flexible cable and assembly; then one end of the first flexible cable 3 is connected to the upper end of the rotating rod 5, and the other end passes through the through hole at the upper end of the pillar 7 and the second fixed snap ring 2 in sequence, and is tensioned and connected with the first fixed snap ring 1;

Then the bridge box 9 and the resistance strain gauge 10 on the top of the cantilever beam 6 form the Whiston measuring bridge by the full bridge method; after the installation is completed, start the testing machine, apply a load to the tested piece 20, and the tested piece 20 is deformed, and then Pulling drives the cantilever beam 6 to produce bending deformation, thereby driving the resistance strain gauge 10 to deform and causing its resistance value to change, so that the measuring bridge outputs a voltage signal ΔU;

Using the data acquisition system of the testing machine to read the voltage signal ΔU output by the bridge box 9, and calculate the deflection δ generated at the lower end of the cantilever beam 6, including the following steps:

得到悬臂梁6在电阻应变片10处沿悬臂梁6的长度方向的线应变ε，η为与测量电桥相关的常数，K为电阻应变片10的灵敏系数，U为测量电桥的供桥电压，测量时K和U为常量；1) According to the electrical stress and strain test method, by

Obtain the line strain ε of the cantilever beam 6 along the length direction of the cantilever beam 6 at the resistance strain gauge 10, η is a constant related to the measurement bridge, K is the gage coefficient of the resistance strain gauge 10, and U is the supply bridge of the measurement bridge Voltage, K and U are constant when measuring;

2) Obtain the bending normal stress σ at this place according to Hu Ke's law σ=E·ε, where: E is the elastic modulus of the material used for the cantilever beam 6;

得到悬臂梁6上电阻应变片10所在截面的弯矩M，式中：W_Z是悬臂梁6的抗弯截面系数；3) According to the bending normal stress formula

Obtain the bending moment M of the section where the resistance strain gauge 10 is located on the cantilever beam 6, in the formula: W _Z is the bending section coefficient of the cantilever beam 6;

4) The concentrated force P on the lower end of the cantilever beam 6 is obtained from the material mechanics formula M=P·l′, where l′ is the distance from the section where the resistance strain gauge 10 on the upper part of the cantilever beam 6 is located to the lower end of the cantilever beam 6;

5) By the bending deflection formula of the beam Calculate the deflection δ that the cantilever beam 6 lower end produces, wherein l, I are the length and the section moment of inertia of the cantilever beam 6 respectively;

Finally, separate the length ratio of the upper and lower parts of the rotating rod 5 according to the pin hole position of the rotating rod 5, determine the linear proportional coefficient k between the deflection δ of the lower end of the cantilever beam 6 and the deformation of the tested piece 20, and multiply the coefficient k by the deflection of the cantilever beam 6 δ, so as to obtain the deformation amount of the tested object 20.

In addition, the measurement accuracy of the device can be further improved by calibrating the measurement results.

Claims (9)

1. a Multipurpose deformation measurement mechanism, it is characterized in that comprising the pillar (7) of lower end with base, depart from the crossbeam (21) that center line has a through hole, the uniform bull stick (5) that offers a plurality of radially pin-and-holes, semi-girder (6), the first flexible cable (3), the second flexible cable (4), the first fixing snap ring (1), the second fixedly snap ring (2) and vernier scale (18), the upper and lower side of wherein said pillar (7) has a radial direction through hole, described crossbeam (21) is solidly set on above position, pillar (7) middle part by through hole, the perpendicular connection of one end of the left end of described crossbeam (21) and described semi-girder (6), the arbitrary pin-and-hole pin joint of the right-hand member of described crossbeam (21) and described bull stick (5) middle part, one end of described the first flexible cable (3) is connected with the upper end of described bull stick (5), the other end is successively through described pillar (7) upper end through hole, second fixedly snap ring (2) with first fixedly snap ring (1) be connected, one end of described the second flexible cable (4) is connected with the lower end of described bull stick (5), the other end is connected with described semi-girder (6) other end through described pillar (7) lower end through hole, described first fixedly snap ring (1) with second fixedly snap ring (2) also with the described vernier scale (18) near test specimen (20), be connected respectively, described crossbeam (21) left end upper surface also is provided with the bridge box (9) be electrically connected to the resistance strain gage (10) that is arranged on described semi-girder (6) top.

2. Multipurpose deformation measurement mechanism according to claim 1, is characterized in that, described first fixedly snap ring (1), second fixedly snap ring (2) be the scissor-shaped spring clamp.

3. Multipurpose deformation measurement mechanism according to claim 2, is characterized in that, the chuck of described scissor-shaped spring clamp is provided with the clamping blade of indent mutually to the inside, and outer middle side part is equipped with the protruding handle of a projection, and the cross connection position has through hole.

4. Multipurpose deformation measurement mechanism according to claim 1, it is characterized in that, described device when measuring compression deformation first fixedly snap ring (1), second fixedly on snap ring (2) also flexible connection be useful on the reversing-gear (17) of back transfer test specimen (20) deformation direction.

5. Multipurpose deformation measurement mechanism according to claim 4, it is characterized in that, described reversing-gear (17) is comprised of loop bar, sleeve, described sleeve is set in the loop bar middle part, the top of loop bar and sleeve, bottom all radially are provided with the thrust of opposite direction, wherein the thrust of loop bar top and sleeve bottom also is respectively equipped with and the second fixing snap ring (2), first central blind hole that fixedly the protruding handle in snap ring (1) outside is flexibly connected, and the thrust at loop bar bottom and sleeve top all has the radial direction through hole for the company's of wearing the first flexible cable (3).

6. Multipurpose deformation measurement mechanism according to claim 1, is characterized in that, between arbitrary angle that described bull stick (5) and crossbeam (21) form mutually, is provided with back-moving spring (8).

7. Multipurpose deformation measurement mechanism according to claim 1, the material that it is characterized in that the base of described pillar (7) is magnetic material.

8. Multipurpose deformation measurement mechanism according to claim 1, is characterized in that, described the first flexible cable (3) adopts the invar alloy material with the second flexible cable (4).

9. the measuring method of a Multipurpose deformation measurement mechanism as claimed in claim 1 is characterized in that comprising the following steps:

1) check fixedly vernier scale (18) gauge length, according to by side test specimen (20) material, being selected bull stick (5) and crossbeam (21) pin joint pin-and-hole position;

2) by vernier scale (18) with first fixedly snap ring (1), second fixedly snap ring (2) be connected, and by first fixedly snap ring (1) and second fixedly snap ring (2) be held on test specimen (20); Lower end through hole by the second flexible cable (4) through pillar (7), the two ends tensioning also is individually fixed in semi-girder (6) lower end and bull stick (5) lower end; The first flexible cable (3) one ends are connected with bull stick (5) upper end, the other end is successively through the fixing snap ring (2) of pillar (7) upper end through hole, second again, tensioning and with first fixedly snap ring (1) be connected;

3) utilize the resistance bridge principle that bridge box (9) and the resistance strain gage (10) on semi-girder (6) top are pressed to the full-bridge connection and form measuring bridge;

4) starting characteristics test machine, to test specimen (20) imposed load, test specimen (20) produces distortion, and then tractive drives semi-girder (6) generation flexural deformation, thereby drive resistance strain gage (10) distortion, cause its resistance value to change, make measuring bridge output voltage signal Δ U;

5) utilize the test engine data acquisition system to read the voltage signal Δ U of bridge box (9) output, obtain semi-girder (6) according to electrical measurement stress, strain experimental technique and locate along the line strain ε of semi-girder (6) length direction at resistance strain gage (10); But substitution Hu law obtains the bending normal stresses σ at this place; Obtain again the moment M in the upper resistance strain gage (10) of semi-girder (6) cross section, place according to the bending normal stresses formula; Moment M obtains the suffered concentrated force P in semi-girder (6) lower end divided by semi-girder (6) top resistance strain gage (10) cross section, place to the distance of semi-girder (6) lower end, gained concentrated force P value substitution sag formula is tried to achieve to the amount of deflection δ of semi-girder (6) lower end generation;

6) separate bull stick (5) top and the bottom length ratio according to bull stick (5) pin-and-hole position, determine the lower end amount of deflection δ of semi-girder (6) and the linear scale factor k between test specimen (20) deflection, coefficient k is multiplied by the amount of deflection δ of semi-girder (6), thereby draws test specimen (20) deflection.

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