CN215574211U - Rubber superelasticity test fixture and test piece thereof - Google Patents

Abstract

The utility model discloses a rubber superelasticity test fixture and a test specimen thereof, wherein the test fixture comprises: the utility model adopts single-shaft stretching, comprises a base, a first fixed block arranged on the base, a second fastening fixed block which is matched and fixedly connected with the first fixed block and a tightening screw for fixedly tightening and connecting the first fixed block and the second fixed block, wherein the contact surfaces of the first fixed block and the second fixed block, which are abutted against, are respectively provided with a fixed groove correspondingly, the fixed grooves are correspondingly matched to form an installation part, the second fixed block is provided with a through hole, and the first fixed block is provided with a locking screw hole corresponding to the through hole, the utility model effectively avoids the shape defect of the test piece caused by cutting and manufacturing the test piece and the inaccurate test result caused by sliding of the test piece in the tensile test process.

Description

Rubber superelasticity test fixture and test piece thereof

Technical Field

The utility model relates to the technical field of rubber material testing, in particular to a rubber superelasticity testing clamp and a rubber superelasticity testing test piece.

Background

As shown in fig. 15-17, the vulcanizate superelastic texture test consisted of 3 tests of biaxial tensile test, uniaxial tensile test, and planar tensile test. The existing test piece is made by punching and cutting a vulcanized rubber flat plate with the thickness of 1mm or 2mm by a sample cutter, the test piece is placed in the middle of a flat plate clamp before testing, the distance between two planes of the flat plate clamp is reduced by a fastening screw, the test piece is clamped, and then the tensile test is started.

As shown in fig. 18 to 19, 3 kinds of test pieces of biaxial stretching, uniaxial stretching and planar stretching were prepared by cutting a vulcanized rubber flat plate having a thickness of 1mm or more with a cutter having a corresponding shape, and the quality of the cutting edge of the cutter affected the smoothness of the cut surface of the test piece. In the process that the cutter is pressed down, the cutting edge cuts and generates pressure on the rubber material, and the vulcanized rubber plate deforms in the cutting process due to the pressure. After the cutting is finished, the pressure of the cutting edge of the cutter on the cut tensile test piece is eliminated, the material at the cutting surface position of the test piece shrinks inwards to cause the cut surface to present a double-C-shaped recess, and the section size precision of the test piece after the cutting is finished is directly influenced. The cross section dimension is inaccurate, so that the engineering stress calculated based on the cross section dimension of the test piece in the test process is deviated from the real engineering stress value.

The 3 kinds of test pieces of biaxial stretching, uniaxial stretching and plane stretching are clamped in a flat plate clamp, and the clamp is in a state before fastening. Before the clamp is fastened, the load value of the loading equipment is adjusted to return to 0, and the displacement value of the loading equipment is adjusted to return to 0. The clamping force of the clamp for adjusting the surface distance of the clamp flat plates to the test specimen is reduced through bolt fastening, the clamping part of the rubber material test specimen is compressed under the action of the clamping force, partial rubber materials between 2 flat plates of the clamp flow towards the direction of a non-clamping area before clamping, and the quantity of the rubber materials at the non-clamping position before clamping is increased.

As shown in fig. 20-21, after the test piece is clamped, the end of the clamp is unchanged, the material in the non-clamping area is warped, and the force value sensor of the loading device generates a negative value due to the compression of the material. As the buckling and partial reaction force of the test piece are generated after the test piece is fastened, the load channel of the loading equipment generates a negative value, the initial position and the load value of the equipment need to be readjusted, the test flow is increased, and the accuracy of the test result is influenced.

3 kinds of test pieces of biaxial stretching, uniaxial stretching and plane stretching are clamped in the flat plate clamp, the surface distance of the flat plate of the clamp is reduced through bolt fastening to provide the constraint force of a test piece loading end, and the distance of the flat plate clamp is kept unchanged in the loading process. Along with the increase of the tensile deformation, the rubber thickness of the non-clamping position is reduced, when the rubber material thickness of the non-clamping position is smaller than the rubber thickness of the clamping position, the clamping force of the clamp disappears, part of the rubber test piece of the clamping position is separated from the clamp, and the rubber test piece slides. In the test process, the clamping and sliding of the test piece are tested, the real force and displacement parameter values are influenced, and the accuracy of the test result is influenced.

SUMMERY OF THE UTILITY MODEL

In some embodiments of this application, provide a rubber superelasticity test fixture and test specimen thereof, this application adopts the rib rubber specimen of the same vulcanization mould direct vulcanization molding of three kinds of test specimens of uniaxial tension, plane tension, biaxial tension, and the cooperation has the anchor clamps of cylindrical slotted hole to carry out the tensile test of the super elasticity constitutive action of rubber, and this application has effectively avoided the test specimen to cut the test specimen shape defect that the preparation leads to and the test result that the test specimen slided and leads to is inaccurate among the tensile test process.

In some embodiments of this application, improved test piece, the test piece of this application adopts the fashioned mode of direct vulcanization to make, vulcanizes ripe drawing of patterns and parks 24 hours after, need not the cut-off knife and cuts, can directly be used for the test, has avoided the cut-off knife to cut the incision section that vulcanized rubber board preparation test piece process leads to and has appeared "two C" type sunken problem.

In some embodiments of this application, improved rubber superelasticity test fixture, this application is provided with installation department and clamping part, and the mode centre gripping of the cylindrical installation department centre gripping vulcanized rubber test piece cylindrical clamping part that this application adopted test fixture, under the test condition of big meeting an emergency, clamping part and installation department can provide sufficient restraint power, and the test piece that does not take place the clamping position slides under the regional tensile deformation thickness of vulcanized rubber test reduces, obtains accurate loading power and loading displacement test result.

In some embodiments of the application, a rubber superelasticity test fixture is provided, which includes a base, a first fixing block arranged on the base, a second fastening fixing block matched and connected and fixed with the first fixing block, and a tightening screw for fixing and tightening the first fixing block and the second fixing block, wherein the second fixing block is abutted against the first fixing block, and contact surfaces of the first fixing block and the second fixing block, which are abutted against each other, are respectively provided with a fixing groove correspondingly, and the fixing grooves are correspondingly matched to form an installation part; the second fixing block is provided with a through hole, and the first fixing block is provided with a locking screw hole corresponding to the through hole; and the tightening screw penetrates through the through hole and is screwed in the locking screw hole.

In some embodiments of the present application, a rubber superelasticity test specimen is provided, the specimen including a specimen body and a clamping portion disposed at an end of the specimen; wherein the clamping portion is clamped by a plurality of the rubber superelasticity test clamps.

In some embodiments of the present application, the test piece body includes a central area and a tensile area, the central area is square, the four tensile areas extend outwards around the central area and form a cross shape, and the end of the tensile area is provided with the clamping portion; the clamping part is clamped by four rubber superelasticity test clamps.

In some embodiments of the present application, the stretching zone is provided as a vulcanized rubber flat sheet having a thickness of 1mm or more and a length of 34 mm.

In some embodiments of the present application, the gripping portion is provided as a cylindrical gripping rib having a diameter of 4mm and an axial height of 34 mm.

In some embodiments of the present application, a circular arc edge transition fillet with a radius of 3mm is disposed between two adjacent stretching regions.

In some embodiments of the present application, a rubber superelasticity test piece is provided, wherein the shape of the test piece body is an approximately rectangular structure, and two ends of the test piece body are provided with loading areas; two sides of the middle position of the test piece are oppositely and inwardly formed into symmetrical circular arc transition with the radius of 20mm along the length direction to form a stretching area, and the clamping part is connected with the loading area along the width direction of the test piece; the clamping part is clamped by the two rubber superelasticity test clamps.

In some embodiments of the present application, the clamping portions at both ends of the test piece are provided as cylindrical ribs having a diameter of 4mm and an axial height of 14 mm; the test piece body is an approximately cuboid vulcanized rubber flat plate with the thickness of 1mm, and the width of the loading areas at two ends of the test piece is 14 mm; the position that the distance is nearest on stretching zone middle part both sides limit is 6mm, just stretching zone body length is 24 mm.

In some embodiments of the present application, there is provided a rubber superelasticity test piece, wherein the test piece body is rectangular and includes a tensile zone, and the clamping portions are connected to both ends of the test piece along the length direction of the test piece; the clamping part is clamped by two rubber superelasticity test clamps.

In some embodiments of the present application, the clamping portion is configured to: a cylindrical rib having a diameter of 4mm and an axial height of 150 mm; the stretching zone is set as follows: the length is 150mm, the width is 15mm, and 1 mm's of thickness rectangular solid vulcanized rubber flat plate.

Drawings

FIG. 1 is a schematic view of the installation fit of a rubber superelastic test fixture and a test specimen in some embodiments of the present application;

FIG. 2 is a schematic view of a vulcanization mold for a test piece in some embodiments of the present application;

FIG. 3 is one of the schematic structural views of a test specimen in some embodiments of the present application;

FIG. 4 is a second schematic structural view of a test specimen in some embodiments of the present application;

FIG. 5 is a third schematic structural view of a test specimen in some embodiments of the present application;

FIG. 6 is a schematic diagram of a pre-stretched structure of a test piece of a uniaxial tensile test in some embodiments of the present application;

FIG. 7 is a schematic diagram of the fit of a uniaxial tensile test in some embodiments of the present application;

FIG. 8 is a schematic drawing of a post-tensile structure of a test piece of a uniaxial tensile test in some embodiments of the present application;

FIG. 9 is a schematic diagram of a pre-tensile specimen for a plane tensile test in some embodiments of the present application;

FIG. 10 is a fit schematic of a planar pull test in some embodiments of the present application;

FIG. 11 is a schematic drawing of a post-tensile structure of a test piece of a planar tensile test in some embodiments of the present application;

FIG. 12 is a schematic representation of the pre-stretched structure of a specimen for a biaxial tensile test in some embodiments of the present application;

FIG. 13 is a schematic diagram of the mating of biaxial tensile tests in some embodiments of the present application;

FIG. 14 is a schematic drawing of the post-tensile structure of a test piece of a biaxial tensile test in some embodiments of the present application;

FIG. 15 is a schematic view of a test piece structure of a biaxial tensile test in the prior art;

FIG. 16 is a schematic view of a test piece structure of a uniaxial tension test in the prior art;

FIG. 17 is a schematic view of a test piece structure of a plane tensile test in the prior art;

FIG. 18 is one of the cut-off surface defects of a test piece in the prior art;

FIG. 19 is a second schematic diagram of a prior art test piece showing a defect in the cut surface;

FIG. 20 is a schematic view of a prior art test piece prior to clamping;

FIG. 21 is a schematic view of a prior art clamped test piece;

in the figure:

100. a base; 110. a first fixed block; 111. locking the screw hole; 120. a second fixed block; 121. a through hole; 130. fixing grooves; 131. an installation part; 200. a test piece; 210. a test piece body; 220. a clamping portion; 221. a cylindrical gripping rib.

Detailed Description

The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the utility model but are not intended to limit the scope of the utility model.

In the description of the present application, it is to be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing the present application and simplifying the description, but do not indicate or imply that the referred device or element must have a particular orientation, be constructed in a particular orientation, and be operated, and thus should not be construed as limiting the present application.

The terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, "a plurality" means two or more unless otherwise specified.

In the description of the present application, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.

The following is a description of preferred embodiments of the present invention with reference to the accompanying drawings.

As shown in fig. 1, a rubber superelastic test fixture and test specimen therefor according to some embodiments of the present application, comprising: the rubber superelasticity test fixture is arranged on a telescopic rod of a rubber biaxial tensile testing machine in the prior art.

The rubber superelastic test fixture is used to hold the test piece 200 for superelastic tensile testing.

The extension rod is driven by the driving device (electric cylinder) to extend and retract to perform the tensile test of the test piece 200.

In this application, test fixture includes fastening seat and fastening cooperation portion, is provided with fixed axle sleeve on the fastening seat, and fixed axle sleeve is used for fastening seat detachably fixed connection on the telescopic link, still is provided with on the fastening seat and places the plane for be connected with fastening cooperation portion plane contact cooperation.

As shown in fig. 1, a rubber superelastic test clamp according to some embodiments of the present application, comprising: the base 100, the base 100 is provided with a first fixed block 110, a second fixed block 120 and a tightening screw.

The second fixing block 120 is fixed to the first fixing block 110 in a matched and connected manner, the first fixing block 110 and the second fixing block 120 are fixedly connected in a tightened manner by tightening screws, and the second fixing block 120 is abutted against the first fixing block 110.

In this application, the second fixing block 120 is provided with a through hole 121, the first fixing block 110 is provided with a locking screw hole 111 corresponding to the through hole 121, and the tightening screw passes through the through hole 121 and is screwed in the locking screw hole 111.

As shown in fig. 1, a rubber superelastic test clamp according to some embodiments of the present application, comprising: the fixing groove 130 is provided with a mounting part 131 correspondingly matched with the fixing groove 130.

The fixing groove 130 is used to fix the test specimen 200.

The contact surfaces of the first fixing block 110 and the second fixing block 120 are respectively provided with a fixing groove 130 correspondingly.

As shown in fig. 3-5, a rubber superelastic test fixture and test specimen therefor according to some embodiments of the present application, comprising: a test piece 200.

The test piece 200 includes a test piece body 210 and a clamping portion 220 provided at an end of the test piece 200.

In the present application, the clamping portion 220 is clamped by a plurality of rubber superelastic test clamps.

It should be noted that, in the present application, the cylindrical mounting portion 131 of the test fixture is used to clamp the cylindrical clamping portion 220 of the vulcanized rubber test piece 200, and under a large strain test condition, the clamping portion 220 and the mounting portion 131 can provide sufficient constraint force, so that the test piece 200 at the clamping position does not slip when the tensile deformation thickness of the vulcanized rubber test area is reduced, and accurate loading force and loading displacement test results are obtained.

As shown in fig. 6 to 14, the rubber superelasticity test fixture and test specimen thereof according to some embodiments of the present application, the vulcanized rubber superelasticity constitutive test thereof consists of 3 tests of biaxial tensile test, uniaxial tensile test and planar tensile test.

As shown in FIGS. 12-14, a test piece 200 for biaxial tensile testing in accordance with some embodiments of the present application includes: the test piece 200 body, the test piece 200 body is comprised of a central zone and a tensile zone.

The central area is square, the four stretching areas extend outwards around the central area and form a cross shape, and the end parts of the stretching areas are provided with clamping parts 220; the clamping portion 220 is clamped by four rubber superelastic test clamps.

In this application, stretch zone sets up to 1MM isopachous, and length is 34 MM's vulcanized rubber flat board, and clamping part 220 sets up to the diameter to be 4MM, axial height 34 MM's cylindrical clamping rib 221, is provided with the circular arc edge transition fillet that the radius is 3MM between two adjacent stretch zones.

As shown in fig. 9-11, a test piece 200 for a planar tensile test according to some embodiments of the present application includes: the test piece body 210 is approximately rectangular in shape.

The test piece body 210 is provided with loading areas at two ends.

The two side edges of the middle position of the test piece 200 are relatively inwards formed into symmetrical circular arc transition with the radius of 20MM along the length direction to form a stretching area, and the clamping part 220 is connected with the loading area along the width direction of the test piece 200; the clamping portion 220 is clamped by two rubber superelastic test clamps.

In the present application, the clamping portions 220 at both ends of the test piece 200 are provided as cylindrical ribs having a diameter of 4MM and an axial height of 14 MM; the body of the test piece 200 is set to be an approximately cuboid vulcanized rubber flat plate with the thickness of 1MM, and the width of the loading areas at two ends of the test piece 200 is set to be 14 MM; the position of the two sides of the middle part of the stretching area, which is closest to the middle part of the stretching area, is 6MM, and the length of the body of the stretching area is 24 MM.

As shown in fig. 6-8, a test piece 200 for uniaxial tensile testing according to some embodiments of the present application includes: the test piece body 210 is rectangular in shape.

The test piece body 210 includes a tensile zone, the clamping portions 220 are connected to both ends of the test piece 200 along the length direction of the test piece 200, and the clamping portions 220 are clamped by two rubber superelasticity test clamps.

In the present application, the clamping portion 220 is configured as: a cylindrical rib having a diameter of 4MM and an axial height of 150 MM; the stretching area is set as follows: the rubber is 150MM in length, 15MM in width and 1MM in thickness.

As shown in fig. 2, the 3 tensile mode test pieces 200 of the present application, according to the test pieces in some embodiments of the present application, are formed in the principle: unvulcanized rubber was filled into the same vulcanization mold in which 3-dimensional cavities in the shape of 3 kinds of test pieces 200 were machined, and the same vulcanization procedure was performed to obtain a vulcanized rubber test piece 200.

Wherein, the vulcanization mould utensil includes: the vulcanizing upper die is provided with a test piece 200 cavity, the vulcanizing lower die is provided with a test piece 200 cavity, the vulcanizing die test piece 200 cavity and unvulcanized rubber filled in the die cavity.

In this application, 3 kinds of test pieces 200 of this application adopt the fashioned mode of direct vulcanization to make, vulcanize ripe drawing of patterns and park 24 hours after, need not the cut-off knife and cut, can directly be used for the test, avoided the influence of vulcanization condition fluctuation to material performance, avoided the cut-off knife quality to the influence of test piece 200 cutting face roughness, avoided the original plan cut-off knife to cut the incision section that vulcanized rubber board preparation test piece 200 process leads to and appear "two C" sunken problem of type.

In the present application, the processing form of the test specimen 200 may be any mold forming process, such as injection molding, compression molding, etc., and the specific size of the test specimen 200 may be adjusted according to the thickness of the test area of the test specimen 200, which is not described herein. While certain representative embodiments and details have been shown for purposes of illustrating the subject utility model, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the scope of the subject utility model.

As shown in fig. 1 and 6-14, the clamping process for uniaxial tensile testing according to some embodiments of the present application is:

s1, standing the test piece 200 for more than 24 hours at room temperature after vulcanization and maturation;

s2, mounting a rubber superelasticity test clamp on loading equipment, resetting the load and resetting the displacement;

s3, loosening the tightening screw, and taking down the first fixing block 110 of the rubber superelasticity test fixture;

s4, placing the clamping part 220 at the end of the test piece 200 into the mounting part 131 of the rubber superelasticity test fixture:

and S5, placing the first fixing block 110 in the original position, and threading a tightening screw through the through hole 121 and screwing the tightening screw into the locking screw hole 111.

In this application, after test piece 200 centre gripping, this application need not additionally to adjust equipment loading axle position, can directly begin the test procedure of the super elastic structure of rubber.

As shown in fig. 1 and 6-14, the specimen 200 clamping process for the biaxial tension test and the plane tension test is the same as the specimen 200 clamping process for the uniaxial tension test according to some embodiments of the present application and will not be described herein.

According to the first concept of the application, because the ribbed rubber test piece is directly vulcanized and formed by adopting the same vulcanizing mold of three test pieces of uniaxial stretching, plane stretching and biaxial stretching, and the fixture with the cylindrical slotted hole is matched for the tensile test of the rubber superelasticity constitutive behavior, the test piece shape defect caused by the cutting and manufacturing of the test piece and the test result caused by the sliding of the test piece in the tensile test process are effectively avoided.

According to the second conception of this application, owing to this application has improved test specimen, the test specimen of this application adopts the fashioned mode of direct vulcanization to make, vulcanizes ripe drawing of patterns and parks 24 hours after, so this application need not the cut-off knife and cuts, can directly be used for the test, has avoided the cut-off knife to cut the incision section that vulcanized rubber board preparation test piece process leads to and has appeared "two C" sunken problem of type.

According to the third conception of the application, because rubber hyperelasticity test fixture has been improved to this application, this application is provided with installation department and clamping part, this application adopts the cylindrical installation department centre gripping of test fixture cylindrical clamping part of vulcanite test piece mode centre gripping, so this application is under the test condition of big meeting an emergency, clamping part and installation department can provide sufficient restraint power, the test piece that does not take place clamping position slides under the condition that the regional tensile deformation thickness of vulcanite test reduces, obtain accurate loading power and loading displacement test result.

The above is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and substitutions can be made without departing from the technical principle of the present invention, and these modifications and substitutions should also be regarded as the protection scope of the present invention.

Claims (9)

1. A rubber superelasticity test fixture comprises a base, a first fixing block arranged on the base, a second fixing block matched and fixedly connected with the first fixing block, and a tightening screw for fixedly tightening and connecting the first fixing block and the second fixing block;

the fixing device is characterized in that the second fixing block and the first fixing block are abutted against each other, and fixing grooves are correspondingly arranged on contact surfaces of the first fixing block and the second fixing block, which are abutted against each other;

the fixing grooves are correspondingly matched to form mounting parts;

the second fixing block is provided with a through hole, and the first fixing block is provided with a locking screw hole corresponding to the through hole;

and the tightening screw penetrates through the through hole and is screwed in the locking screw hole.

2. A rubber superelasticity test specimen is characterized by comprising a specimen body and a clamping part arranged at the end part of the specimen body;

the test piece body comprises a central area and four stretching areas, the central area is square, the four stretching areas extend outwards around the central area and form a cross shape, and the end parts of the stretching areas are provided with the clamping parts;

the clamping portion is clamped by four rubbery superelastic test clamps as described in claim 1.

3. A rubber superelasticity test specimen according to claim 2, wherein said tensile zone is provided as a flat vulcanized rubber sheet having a thickness of 1mm and a length of 34 mm.

4. A rubber superelastic test specimen according to claim 2, wherein said clamping portion is provided as a cylindrical clamping rib having a diameter of 4mm and an axial height of 34 mm.

5. The rubber superelasticity test specimen according to claim 2, wherein a rounded edge transition fillet having a radius of 3mm is provided between two adjacent tensile zones.

6. A rubber superelasticity test specimen is characterized by comprising a specimen body and a clamping part arranged at the end part of the specimen body;

the test piece body is of an approximately rectangular structure, and two ends of the test piece body are provided with loading areas;

two sides of the middle position of the test piece are oppositely and inwardly formed into symmetrical circular arc transition with the radius of 20mm along the length direction to form a stretching area, and the clamping part is connected with the loading area along the width direction of the test piece;

the clamping portion is clamped by two rubber superelastic test clamps of claim 1.

7. The rubber superelasticity test specimen according to claim 6, wherein said clamping portions at both ends of said specimen are provided as cylindrical clamping ribs having a diameter of 4mm and an axial height of 14 mm;

the test piece body is an approximately cuboid vulcanized rubber flat plate with the thickness of 1mm, and the width of the loading areas at two ends of the test piece is 14 mm;

the position that the distance is nearest on stretching zone middle part both sides limit is 6mm, just stretching zone body length is 24 mm.

8. A rubber superelasticity test specimen is characterized by comprising a specimen body and a clamping part arranged at the end part of the specimen body;

the test piece body is rectangular and comprises a stretching area, and the clamping parts are connected to two ends of the test piece along the length direction of the test piece;

the clamping portion is clamped by two rubber superelastic test clamps of claim 1.

9. A rubber superelastic test specimen according to claim 8, wherein said clamping portion is configured to: a cylindrical gripping rib having a diameter of 4mm and an axial height of 150 mm;

the stretching zone is set as follows: the length is 150mm, the width is 15mm, and 1 mm's of thickness rectangular solid vulcanized rubber flat plate.

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