CN218956258U - Clamp suitable for tensile test of dumbbell-shaped test piece - Google Patents

Abstract

The utility model relates to the technical field of clamps for tensile testing machines, and specifically discloses a clamp suitable for tensile testing of dumbbell-shaped specimens, comprising: an upper clamp, a lower clamp, a positioning rod, a locking piece and a backing plate. Both the upper chuck and the lower chuck are groove-shaped components formed by bending the two ends of the plate body by 90°, and the groove of the upper chuck is directly opposite to the groove of the lower chuck when in use. The side wall of the upper chuck has first through holes symmetrically distributed on the left and right, the positioning rod is connected with the locking member after passing through the first through hole, and the side wall of the lower chuck has The second through holes are symmetrically distributed on the left and right, and the other positioning rod passes through the second through holes and is connected with the other locking member. The positioning rod is located on the slope at the end of the isosceles trapezoid of the dumbbell-shaped test piece, and the backing plate is clamped between the positioning rod and the slope at the end. The fixture can effectively improve the test efficiency, and can ensure that the components break within the measuring gauge length, thereby improving the test efficiency and reliability.

Description

A fixture suitable for tensile testing of dumbbell-shaped specimens

technical field

The utility model relates to the technical field of clamps for tensile testing machines, in particular to a clamp suitable for tensile testing of dumbbell-shaped specimens.

Background technique

The tensile strength of ordinary concrete, ultra-light high-strength, ultra-high-performance concrete or other materials is mainly tested by a tensile testing machine. During the test, the two ends of the component are usually clamped by the clamp of the testing machine, so that the specimen is in the The axial tension state is then tested by transferring tension to the member by pulling from both ends of the member. For example, the Chinese patent literature with the authorized announcement number CN211955007U discloses a new type of concrete axial tensile test device, the two ends of the tensile concrete specimen are clamped in the slider; A pull rod is provided at the corresponding position of the center, one end of the pull rod is connected to a fixed slider, and the other end of the pull rod is connected to a ball joint assembly, the axes of the pull head and the pull rod coincide; the ball hinge assembly is connected to the universal testing machine through connecting round steel. The device can better guarantee the tension of the axis, better meet the test requirements of stiffness and test accuracy, solve the problem of insufficient stiffness of the existing high-precision universal testing machine, and then accurately test the stress-strain curve of the concrete specimen after the peak strength . The fixtures of many existing tensile testing machines on the market are difficult to ensure that the component breaks within the measuring gauge length, and the damage of the specimen is not within the controllable test range, which affects the efficiency and reliability of the test; in addition, there is a tension load transfer The deficiencies in aspects such as complex methods and complicated device assembly.

Utility model content

The utility model proposes a clamp suitable for the tensile test of dumbbell-shaped specimens, which has the characteristics of simple operation, easy assembly and disassembly, etc., can effectively improve the test efficiency, and can ensure that the components break within the measuring gauge length, improving Test efficiency and reliability. In order to achieve the above object, the technical scheme of the utility model is as follows:

A fixture suitable for tensile testing of dumbbell-shaped specimens, comprising: an upper clamp, a lower clamp, a positioning rod, a locking piece and a backing plate. Wherein: the upper chuck and the lower chuck are both groove-shaped components formed after the two ends of the plate body are bent by 90°, and the groove of the upper chuck is directly opposite to the groove of the lower chuck when in use. The side wall of the upper chuck has first through holes symmetrically distributed on the left and right, the positioning rod is connected with the locking member after passing through the first through hole, and the side wall of the lower chuck has The second through holes are symmetrically distributed on the left and right, and the other positioning rod passes through the second through holes and is connected with the other locking member. When in use, the two ends of the isosceles trapezoid of the dumbbell-shaped test piece are respectively located in the groove of the upper chuck and the groove of the lower chuck, and the positioning rod is located at the end of the isosceles trapezoid of the dumbbell-shaped test piece. On the slope of the end, the backing plate is clamped between the positioning rod and the slope of the end.

Further, the positioning rod is a screw rod, the locking member is a nut, and one end of the positioning rod passes through the through hole and is screwed to the nut.

Further, the first through hole is composed of four through holes, which are respectively distributed on the four corners of the isosceles trapezoid.

Further, the second through hole is composed of four through holes, which are respectively distributed on the four corners of the isosceles trapezoid.

Further, there is an upper connecting piece on the top surface of the upper chuck, which is used for connecting with the telescopic parts of the tensile testing machine.

Further, there is a lower connector on the top surface of the lower clamp, which is used to fix the lower clamp on the tensile testing machine.

Further, both the upper connecting piece and the lower connecting piece are screw rods, which are threadedly connected with the corresponding chucks.

Compared with the prior art, the utility model has the following beneficial effects:

(1) The fixture suitable for the tensile test of dumbbell-shaped specimens of the present utility model adopts the upper chuck and the lower chuck formed by the groove-shaped members formed after the two ends of the plate body are bent 90° to accommodate dumbbell-shaped specimens respectively. The upper end and the lower end of the test piece, and then use the positioning rod and the locking piece to detach and fix the end of the test piece from the inclined side wall of the test piece, which not only enables the fast positioning and alignment of the component and the chuck, but also flexible operation It is simple and easy to disassemble, which effectively improves the test efficiency.

(2) The fixture suitable for the tensile test of dumbbell-shaped specimens of the present utility model is provided with a backing plate between the positioning rod and the specimen, which is not only beneficial to overcome the difficulty of fitting the positioning rod and the specimen well In addition, the extrusion force transmitted by the positioning rod can be more evenly distributed on the side of the specimen through the backing plate during stretching, so as to avoid the stress concentration that is easily caused when the extrusion force is directly transmitted to the specimen through the positioning rod. The problem of the fracture of the specimen from this place can be solved, so as to better control the position of the tensile fracture of the specimen within the measurement gauge length, and improve the accuracy and reliability of the test experiment.

Description of drawings

The accompanying drawings constituting a part of the utility model are used to provide a further understanding of the utility model, and the schematic embodiments of the utility model and their descriptions are used to explain the utility model and do not constitute improper limitations to the utility model.

Fig. 1 is a structural schematic diagram of a fixture suitable for tensile testing of dumbbell-shaped specimens in the following examples.

Fig. 2 is a structural schematic view of the upper chuck and the lower chuck in the following embodiments.

Fig. 3 is a structural schematic diagram of the positioning rod and the backing plate in the following embodiments.

The marks in the figure respectively represent: 1-upper chuck, 2-lower chuck, 3-positioning rod, 4-locking piece, 5-backing plate, 6-dumbbell-shaped test piece, 7-upper connector, 8-lower Connecting piece, 101-first through hole, 201-second through hole.

Detailed ways

It should be pointed out that the following detailed descriptions are all exemplary and are intended to provide further description of the present utility model. Unless otherwise specified, all technical and scientific terms used in this application have the same meaning as commonly understood by those of ordinary skill in the art to which this application belongs.

For the convenience of description, if the words "up", "down", "left" and "right" appear in the utility model, it only means that it is consistent with the up, down, left and right directions of the drawings themselves, and does not limit the structure. It is only for the convenience of describing the utility model and simplifying the description, but does not indicate or imply that the referred device or element needs to have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the utility model.

Explanation of terms: terms such as "installation", "connection", "connection" and "fixation" in this utility model should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integration; It may be a mechanical connection, a direct connection, or an indirect connection through an intermediary. Those skilled in the art can understand the specific meanings of the above terms in the present invention according to specific situations. The technical scheme of the utility model is further described in conjunction with the drawings and specific embodiments of the description.

Referring to FIG. 1 , FIG. 2 and FIG. 3 , a clamp suitable for tensile testing of a dumbbell-shaped specimen is illustrated, including: an upper clamp 1 , a lower clamp 2 , a positioning rod 3 , a locking member 4 and a backing plate 5 . in:

Both the upper clamp 1 and the lower clamp 2 are groove-shaped components formed after the two ends of the plate body are bent by 90°, and the upper clamp 1 is located directly above the lower clamp 2 when in use, and the upper clamp The groove of the head 1 is directly opposite to the groove of the lower chuck 2, so that the upper and lower ends of the dumbbell-shaped test piece 6 are placed in the groove of the upper chuck 1 and the groove of the lower chuck 2 respectively. position. It should be noted that, with reference to the upper and lower ends of the dumbbell-shaped test piece 6 described in Figure 1, it is a symmetrically distributed isosceles trapezoidal block, and between the two ends is the measuring gauge length. When carrying out the tensile test, the Only when the fracture point/fracture surface of the component is controlled within the measurement gauge length can it represent that the test is valid.

The front wall of the upper chuck 1 has first through holes 101 symmetrically distributed on the left and right, and the rear wall of the upper chuck 1 has through holes corresponding to the first through holes 101 . Similarly, the front wall of the lower chuck 2 has second through holes 201 symmetrically distributed on the left and right, and the rear wall of the lower chuck 2 has through holes corresponding to the second through holes 201, Moreover, both the first through hole 101 and the second through hole 201 are located at the slope of the end of the isosceles trapezoidal shape of the dumbbell-shaped test piece 6 . The first through holes 101 and the second through holes 201 are symmetrically distributed up and down.

Both the first through hole 101 and the second through hole 201 are used to fix the upper end and the lower end of the dumbbell-shaped test piece 6 after the positioning rod 3 penetrates, so that it is in contact with the upper chuck 1 and the lower end. Chuck 2 is connected as a whole. Specifically, when testing, the upper end and the lower end of the dumbbell-shaped test piece 6 are respectively placed in the groove of the upper chuck 1 and the groove of the lower chuck 2, and then the positioning rod 3 is passed through the groove. The first through hole 101 on the front wall surface of the above-mentioned chuck 1 and the corresponding through hole on the rear wall surface, the two ends of the positioning rod 3 are screw rods, the locking member 4 is a nut, and then on the positioning rod 3 Both ends are screwed to the nuts and fastened, and the positioning rod 3 is fixed on the upper chuck 1. At this time, the positioning rod 3 is located at the upper end of the isosceles trapezoidal shape of the dumbbell-shaped test piece 6. Inclined surface, thereby the upper end of described dumbbell-shaped test piece 6 is fixed in the groove of upper clamp 1, can avoid the upper end of dumbbell-shaped test piece 6 from breaking away from upper clamp 1 when carrying out tensile test. The lower end of the dumbbell-shaped test piece 6 is fixed in the groove of the lower chuck 2 in the same manner. In this embodiment, the upper chuck 1 and the lower chuck 2 formed by the groove-shaped members formed after the two ends of the plate body are bent by 90° respectively accommodate the upper end and the lower end of the dumbbell-shaped test piece 6, and then the positioning rod 3 and the lock are used. The fastener 4 detachably fixes the end of the test piece from the inclined side wall of the test piece, which not only enables the fast positioning and alignment of the component and the chuck, but also is flexible and easy to operate, easy to disassemble, and effectively improves the test efficiency.

Further, the present embodiment is also provided with a backing plate 5 made of steel between the positioning rod 3 and the inclined surface of the end of the dumbbell-shaped test piece 6. When setting, the upper end of the dumbbell-shaped test piece 6 and the Put the lower end in the groove of the upper chuck 1 and the groove of the lower chuck 2, then stick the backing plate 5 on the inclined surface of the end of the dumbbell-shaped test piece 6, and then penetrate the positioning rod 3 to fix. By setting the backing plate 5 between the positioning rod 3 and the test piece, it not only helps to overcome the problem that the positioning rod 3 and the test piece are not easy to fit well, but also can reduce the extrusion force transmitted by the positioning rod 3 during stretching. The force is more evenly distributed on the side of the test piece through the backing plate 5, avoiding the problem that the stress concentration is easily caused when the extrusion force is directly transmitted to the test piece through the positioning rod 3, and the test piece is broken from this place, so that the test piece can be better placed. The position of the tensile fracture of the part is controlled within the measurement gauge length, which improves the accuracy and reliability of the test experiment.

Continuing to refer to FIG. 1 to FIG. 3 , in another embodiment, the first through hole 101 is composed of four through holes, which are respectively distributed on the four corners of an isosceles trapezoid. Similarly, the second through hole 201 is composed of four through holes, which are respectively distributed on the four corners of the isosceles trapezoid, which not only makes the connection between the dumbbell-shaped test piece 6 and the chuck more firm, but also makes it more stable. Evenly carry out the transmission and distribution of tensile force/load, better control the position of the tensile fracture of the specimen within the measurement gauge length, and improve the accuracy and reliability of the test experiment

Continuing to refer to FIG. 1 to FIG. 3 , in another embodiment, the upper clamp 1 has an upper connecting member 7 on the top surface thereof, which is used for connecting with the telescopic parts of the tensile testing machine. There is a lower connector 8 on the top surface of the lower clamp 2, which is used to fix the lower clamp 2 on the tensile testing machine. Specifically, both the upper connecting member 7 and the lower connecting member are screw rods, which are fastened to the corresponding chucks by bolts, so as to facilitate disassembly and assembly.

Finally, it should be noted that any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present utility model shall be included in the protection scope of the present utility model. Although the specific implementation of the utility model has been described above in conjunction with the accompanying drawings, it does not limit the protection scope of the utility model. Those skilled in the art should understand that on the basis of the technical solution of the utility model, those skilled in the art do not need to Various modifications or deformations that can be made with creative efforts are still within the protection scope of the present utility model.

Claims (7)

1. A fixture suitable for tensile testing of dumbbell-shaped specimens, characterized in that it comprises: an upper chuck, a lower chuck, a positioning rod, a locking member and a backing plate; wherein: the upper chuck, the lower chuck The heads are all groove-shaped components formed by bending the two ends of the plate body by 90°, and the groove of the upper chuck is directly opposite to the groove of the lower chuck when in use; the side wall of the upper chuck has The first through hole is symmetrically distributed on the left and right, the positioning rod is connected with the locking member after passing through the first through hole, the side wall of the lower chuck has the second through hole symmetrically distributed on the left and right hole, and the other positioning rod is connected with the other locking member after passing through the second through hole; When in use, the clamp has the following state: the two ends of the isosceles trapezoid of the dumbbell-shaped test piece are respectively located in the groove of the upper clamp and the groove of the lower clamp, and the positioning rod is located in the groove of the dumbbell. On the slope of the end of the isosceles trapezoid of the type test piece, the backing plate is clamped between the positioning rod and the slope of the end. 2. The clamp suitable for the tensile test of the dumbbell-shaped specimen according to claim 1, wherein the positioning rod is a screw rod, the locking member is a nut, and one end of the positioning rod passes through the Threaded connection with the nut after the through hole. 3. The clamp suitable for the tensile test of the dumbbell-shaped specimen according to claim 1, wherein the first through hole is composed of four through holes, which are respectively distributed on the four corners of the isosceles trapezoid . 4. The clamp suitable for the tensile test of the dumbbell-shaped specimen according to claim 1, wherein the second through hole is composed of four through holes, which are respectively distributed on the four corners of the isosceles trapezoid . 5. The clamp suitable for tensile testing of dumbbell-shaped specimens according to any one of claims 1-4, characterized in that, an upper connecting piece is provided on the top surface of the upper chuck. 6 . The clamp suitable for tensile testing of dumbbell-shaped specimens according to claim 5 , wherein a lower connector is provided on the top surface of the lower chuck. 7 . 7. The clamp suitable for the tensile test of the dumbbell-shaped specimen according to claim 6, wherein the upper connector and the lower connector are screw rods, which are threadedly connected with the corresponding clamps .

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