Tensile test device for composite grid fabric

Abstract

The utility model discloses a composite grating fabric tensile test device, which relates to the technical field of tensile test of geotextile and composite grating fabric materials, and comprises two symmetrically arranged clamping cavities, the two clamping cavities are respectively arranged at two ends of a test body material, two symmetrical semicircular roller clamping pieces are arranged in the clamping cavities, and the two semicircular roller clamping pieces are respectively arranged on the two ends of the test body material. And one corresponding end of the test body material is clamped between the two semicircular roller clamping pieces and is wound at the outer ends of the two semicircular roller clamping pieces for a circle. According to the utility model, one end of the test body material is clamped between the two semicircular rolling shaft clamping pieces and wound at the outer ends of the semicircular rolling shaft clamping pieces for a circle, and then the tensile test is carried out, so that the tensile force application point of the test body material in the tensile test process is positioned on the outer tangent plane of the semicircular rolling shaft clamping pieces in contact with the test body material; therefore, the stress is balanced, and the damage of an occlusion point generated when a test body material is clamped by a common wedge-shaped occlusion type clamping piece is avoided, so that the accuracy of a test result is greatly improved.

Description

Technical Field

[0001] The utility model relates to the technical field of tensile testing of geotextiles and composite grid fabric materials, in particular to a composite grid fabric tensile testing device. Background Art

[0002] Geogrid composite geotextile is a new type of composite geotechnical material made of glass fiber or high-strength polyester fiber and non-woven fabric through warp weaving or bonding, which organically combines the excellent properties of geogrid and geotextile. It is suitable for construction projects such as highways, railways, water conservancy, airports, ports, land reclamation, landfills, municipal construction, etc., and has multiple functions such as protection, isolation, filtration, reinforcement, anti-seepage, drainage, etc.

[0003] Since the tensile strength of a material is an important material performance indicator, testing the tensile properties of geotextiles and composite grid fabrics is of great significance to the quality of construction projects.

[0004] However, the existing geosynthetics wide strip stretching device has some defects during use. For example, the wedge-shaped clamps and corrugated clamps are all bite-type clamps. For example, a composite material tensile test device with a publication number of CN220040055U in the prior art has a bite-type clamping method for the specimen, which will cause the specimen to bite and break at the bite contact point between the clamp and the specimen material. When performing a tensile test, the tensile fracture strength value of the specimen material is lower than the true strength value, causing distortion of the test results.

[0005] Therefore, we propose a composite grid fabric tensile test device to solve the bite damage of the fixture to the specimen material in the tensile test and improve the accuracy of the test results. Utility Model Content

[0006] To this end, the utility model provides a composite grid fabric tensile test device to solve the problem in the prior art that the tensile fracture strength value is lower than the true strength value due to specimen bite damage caused by the bite contact point between the clamp and the specimen material, resulting in distortion of the test result.

[0007] In order to achieve the above-mentioned purpose, the utility model provides the following technical solutions: a composite grid fabric tensile test device, used for testing a specimen material, comprising two symmetrically arranged clamping cavities, the two clamping cavities are respectively arranged at both ends of the specimen material, two symmetrical semicircular roller clamps are arranged inside the clamping cavities, and one corresponding end of the specimen material is clamped between the two semicircular roller clamps and wrapped around the outer ends of the two semicircular roller clamps;

[0008] Through grooves are provided on both sides of the clamping cavity, and limiting grooves are provided on the inner walls of the through grooves. Square protrusions are fixedly provided at both ends of the semicircular roller clamping piece. In the test state, the two square protrusions on the same side extend to the outside of the clamping cavity through the limiting grooves on the corresponding side, and the outer ends of the square protrusions are in contact with the inner walls of the limiting grooves.

[0009] Both sides of the specimen material are provided with fixing components, the fixing components are clamped on the outer ends of the two square protrusions on the corresponding side, and the two square protrusions are clamped and fixed by the fixing components.

[0010] Furthermore, the semicircular roller clamp is a solid semicircular high-strength steel rod, and a horizontal scale and multiple longitudinal scales are embedded on the contact surface between the semicircular roller clamp and the specimen material, which are used to perform measurements during the process of clamping the specimen material to ensure that the specimen material is clamped in the center position of the semicircular roller clamp.

[0011] Furthermore, the fixing assembly includes a clamping plate, and the two square protrusions on the corresponding side are both located inside the clamping plate, and the two square protrusions are provided with grooves on one side facing the inner wall of the clamping plate;

[0012] A fastening bolt is provided on the rear side of the clamping plate through a thread, and one end of the fastening bolt extends into a groove on the rear square protrusion, and the square protrusion is clamped inside the clamping plate through the fastening bolt.

[0013] Furthermore, a scale rod is provided on the front side of the clamping plate, the rear end of the scale rod extends into the interior of the clamping plate and is fixed with a push plate, the push plate contacts the square protrusion on the front side, and a limit block is fixed on the push plate, and the limit block is located in the groove on the square protrusion on the front side;

[0014] A first spring is fixedly provided on one side of the push plate away from the square protrusion, one end of the first spring is fixedly connected to the inner wall of the clamping plate, and the clamping force on the square protrusion is determined by observing the scale of the scale rod.

[0015] Furthermore, a ball head hinge is provided at one end of the clamping cavity away from the specimen material, and the ball head hinge includes a hemispherical shell fixed on the clamping cavity, a ball head is provided inside the hemispherical shell, and an external rod extending to the outside of the hemispherical shell is fixed on the top of the ball head. The ball head hinge has higher flexibility and can prevent eccentric tension on the specimen material.

[0016] Furthermore, a semicircular fixing wheel is fixedly provided at one end of the square protrusion away from the clamping cavity, and two semicircular fixing wheels located on the same side of the clamping cavity are symmetrically arranged, and the two semicircular fixing wheels can be combined into a complete circle.

[0017] Furthermore, a tension belt is provided between the two semicircular fixed wheels located on the same side of the clamping cavity. The tension belt is clamped and fixed by the two semicircular fixed wheels and wrapped around the outer ends of the two semicircular fixed wheels. The winding direction of the tension belt is opposite to the winding direction of the specimen material so as to offset the influence of the tension during the test on the inner wall of the limiting groove.

[0018] Furthermore, a second spring is fixedly provided at one end of the tension band, a ring is fixedly provided at one end of the second spring, a guide rod is fixedly provided at the corresponding side of the clamping cavity, and the ring is sleeved on the outer end of the guide rod, thereby fixing one end of the second spring.

[0019] The utility model has the following advantages:

[0020] 1. By clamping one end of the specimen material between two semicircular roller clamps and wrapping a circle around the outer end of the semicircular roller clamp, the specimen material is fixed, and then a tensile test is performed, so that the specimen material can be firmly fastened. The key point is that the tensile force application point of the specimen material during the tensile test is located on the outer tangent surface where the semicircular roller clamp and the specimen material contact, so the force is balanced and the bite point damage caused by the ordinary wedge-shaped bite clamp when clamping the specimen material is avoided, thereby greatly improving the accuracy of the test results.

[0021] 2. Pull the clamping cavity by pulling the ball joint. The ball joint of the ball joint can rotate in all directions inside the hemispherical shell. Therefore, under the stress state, the ball joint can freely adjust the force direction of the system to the axial force, avoiding eccentric tension of the specimen, and the test results are more accurate and reasonable. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the implementation of the utility model or the technical solution in the prior art, the following is a brief introduction to the drawings required for the implementation or the prior art description. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0023] The structures, proportions, sizes, etc. illustrated in this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with the technology. They are not used to limit the conditions under which the present invention can be implemented, and therefore have no substantial technical significance. Any structural modification, change in proportion or adjustment of size shall still fall within the scope of the technical contents disclosed in the present invention without affecting the effects and purposes that can be achieved by the present invention.

[0024] Figure 1 The test state structure diagram provided for the utility model;

[0025] Figure 2 The utility model provides Figure 1 Enlarged view of part A in the middle;

[0026] Figure 3 The overall structure diagram provided for the utility model;

[0027] Figure 4 A structural diagram of the clamping cavity provided by the utility model;

[0028] Figure 5 A structural diagram of a semicircular roller clip provided by the utility model;

[0029] Figure 6 A side sectional view of the semicircular roller clip provided by the utility model in the use state;

[0030] Figure 7 A side sectional view of a fixing assembly provided by the utility model;

[0031] Figure 8 This is a cross-sectional view of the ball joint provided by the utility model.

[0032] In the figure: 1. specimen material; 2. clamping cavity; 3. ball head hinge; 301. hemispherical shell; 302. ball head; 303. external rod; 4. semicircular roller clamp; 5. fixing assembly; 501. clamping plate; 502. push plate; 503. first spring; 504. scale rod; 6. semicircular fixed wheel; 7. tension belt; 8. second spring; 9. collar; 10. guide rod; 11. through groove; 12. limit groove; 13. horizontal scale; 14. vertical scale; 15. square protrusion. DETAILED DESCRIPTION

[0033] The following is a specific embodiment of the present invention. People familiar with the technology can easily understand the other advantages and functions of the present invention from the contents disclosed in this specification. Obviously, the described embodiment is a part of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] like Figure 1-8 As shown, the utility model provides a composite grid fabric tensile test device for testing a specimen material 1, comprising two symmetrically arranged clamping cavities 2, the two clamping cavities 2 are respectively arranged at both ends of the specimen material 1, two symmetrical semicircular roller clamps 4 are arranged inside the clamping cavities 2, and a corresponding end of the specimen material 1 is clamped between the two semicircular roller clamps 4 and wrapped around the outer ends of the two semicircular roller clamps 4;

[0035] Through grooves 11 are provided on both sides of the clamping cavity 2, and limiting grooves 12 are provided on the inner wall of the through grooves 11. Square protrusions 15 are fixedly provided on both ends of the semicircular roller clamping piece 4. In the test state, the two square protrusions 15 on the same side extend to the outside of the clamping cavity 2 through the limiting grooves 12 on the corresponding side, and the outer ends of the square protrusions 15 are in contact with the inner wall of the limiting grooves 12;

[0036] Fixing components 5 are provided on both sides of the specimen material 1 . The fixing components 5 are clamped on the outer ends of the two square protrusions 15 on the corresponding side. The two square protrusions 15 are clamped and fixed by the fixing components 5 .

[0037] Before the test begins, both ends of the specimen material 1 are fixed by the semicircular roller clamps 4. When fixed, the corresponding end is placed between the two semicircular roller clamps 4. The specimen material 1 is clamped by the semicircular roller clamps 4, and then one end of the specimen material 1 is wrapped around the outer ends of the two semicircular roller clamps 4. Then, the square protrusion 15 originally located inside the through groove 11 is inserted into the limiting groove 12. The size of the through groove 11 is larger than the size of the limiting groove 12. The square protrusion 15 can roll unrestricted inside the through groove 11, which is convenient for winding the specimen material 1. When the winding is completed and the square protrusion 15 is inserted into the limiting groove 12, the limiting groove 12 can limit the rotation of the square protrusion 15 and the semicircular roller clamp 4 to fix them. After the square protrusion 15 is inserted into the limiting groove 12, the two square protrusions 15 on the same side of the clamping cavity 2 are clamped and fixed by the fixing component 5.

[0038] By fixing the two ends of the specimen material 1 in this way and then performing the tensile test, the specimen material 1 can be firmly fastened. The key point is that the tensile force application point of the specimen material 1 during the tensile test is located at the outer tangent surface where the semicircular roller clamp 4 contacts the specimen material 1. Therefore, the force is balanced and the damage to the bite point caused by the ordinary wedge-shaped bite clamp clamping the specimen material 1 is avoided, thereby greatly improving the accuracy of the test results.

[0039] When the sample material 1 is clamped between the two semicircular roller clamps 4, the clamping position needs to be measured, such as Figure 5 As shown, the semicircular roller clamp 4 is a solid semicircular high-strength steel rod, and a horizontal scale 13 and multiple longitudinal scales 14 are embedded on the contact surface between the semicircular roller clamp 4 and the specimen material 1, which are used to measure during the process of clamping the specimen material 1 to ensure that the specimen material 1 is clamped in the center position of the semicircular roller clamp 4.

[0040] When one end of the specimen material 1 is clamped between the two semicircular roller clamps 4, the distance between the edge positions on both sides of the specimen material 1 and the edge positions on both ends of the semicircular roller clamps 4 is detected by the scale on the horizontal scale 13 to ensure that the specimen material 1 is located in the middle of the semicircular roller clamps 4. At the same time, the vertical scale 14 is used to measure the distance between the horizontal edge of the specimen material 1 and the horizontal edge of the semicircular roller clamps 4, so that the horizontal edges of the specimen material 1 and the semicircular roller clamps 4 are parallel to each other to avoid the deviation of the pulling force during the test. The premise of this measurement and fixing method is that the specimen material 1 is a standard rectangle with straight edges.

[0041] By clamping the square protrusion 15 with the fixing assembly 5, it is possible to ensure that the fixing force on both ends of the semicircular roller clamp 4 is the same. Figure 1 , 2 As shown in , 3, and 7, the fixing assembly 5 includes a clamping plate 501, and two square protrusions 15 on the corresponding side are both located inside the clamping plate 501, and grooves are provided on the side of the two square protrusions 15 facing the inner wall of the clamping plate 501;

[0042] A fastening bolt is threadedly provided on the rear side of the clamping plate 501 , one end of which extends into a groove on the rear square protrusion 15 , and the square protrusion 15 is clamped inside the clamping plate 501 by the fastening bolt.

[0043] A scale rod 504 is provided at the front side of the clamping plate 501. The rear end of the scale rod 504 extends into the interior of the clamping plate 501 and is fixed with a push plate 502. The push plate 502 contacts the square protrusion 15 at the front side. A limit block is fixed on the push plate 502. The limit block is located in the groove on the square protrusion 15 at the front side.

[0044] A first spring 503 is fixedly provided on one side of the push plate 502 away from the square protrusion 15 . One end of the first spring 503 is fixedly connected to the inner wall of the clamping plate 501 . The clamping force of the square protrusion 15 can be determined by observing the scale of the scale rod 504 .

[0045] After the two fixing components 5 are clamped inside the clamping plate 501, one end of the fastening bolt is inserted into the groove on the rear square protrusion 15, and the fastening bolt is gradually tightened to squeeze the two square protrusions 15. As the square protrusion 15 is pushed by the fastening bolt, the push plate 502 is forced to gradually move forward, the first spring 503 is compressed, and the scale rod 504 also moves with the push plate 502. In this way, the elastic force of the first spring 503 is used to push the scale rod 504 to clamp the two square protrusions 15 between the fastening bolt and the push plate 502. By observing the scale of the scale rod 504, the degree of compression of the first spring 503 can be reflected, and then the force of fixing the square protrusion 15 can be known. In this way, the square protrusions 15 on both sides of the clamping cavity 2 can be clamped and fixed with the same force, ensuring that the fixing force of the specimen material 1 can be more uniform.

[0046] In order to avoid eccentric tension of the specimen material 1, Figure 1 , 8 As shown, a ball hinge 3 is provided at one end of the clamping cavity 2 away from the specimen material 1. The ball hinge 3 includes a hemispherical shell 301 fixed on the clamping cavity 2, a ball head 302 is provided inside the hemispherical shell 301, and an external rod 303 extending to the outside of the hemispherical shell 301 is fixed on the top of the ball head 302. The ball hinge 3 has higher flexibility and can prevent the specimen material 1 from being eccentrically pulled.

[0047] The ball joint 3 is pulled to pull the clamping cavity 2, and then the specimen material 1 is pulled to complete the test of the specimen material 1. The ball head 302 of the ball joint 3 can rotate in all directions inside the hemispherical shell 301. Therefore, under the stress state, the ball joint 3 can freely adjust the force direction of the system to apply axial force, avoiding eccentric tension of the specimen, and the test result is more accurate and reasonable.

[0048] During the test, the semicircular roller clips 4 and 15 have a tendency to rotate, and the square protrusion 15 applies pressure to the inner wall of the limiting groove 12. In order to reduce the wear on the inner wall of the limiting groove 12, as shown in FIG. Figure 1 , 2 As shown in FIG. 3 , a semicircular fixing wheel 6 is fixedly provided at one end of the square protrusion 15 away from the clamping cavity 2. The two semicircular fixing wheels 6 located on the same side of the clamping cavity 2 are symmetrically arranged, and the two semicircular fixing wheels 6 can be combined into a complete circle.

[0049] A tension belt 7 is provided between the two semicircular fixed wheels 6 located on the same side of the clamping cavity 2. The tension belt 7 is clamped and fixed by the two semicircular fixed wheels 6 and wrapped around the outer ends of the two semicircular fixed wheels 6. The winding direction of the tension belt 7 is opposite to the winding direction of the specimen material 1 so as to offset the influence of the tension during the test on the inner wall of the limiting groove 12.

[0050] A second spring 8 is fixedly provided at one end of the tension belt 7, a collar 9 is fixedly provided at one end of the second spring 8, a guide rod 10 is fixedly provided at the corresponding side of the clamping cavity 2, and the collar 9 is sleeved on the outer end of the guide rod 10, thereby fixing one end of the second spring 8.

[0051] One end of the tension band 7 is fixed by a semicircular fixed wheel 6, and the fixing method is the same as that of the specimen material 1, but the winding direction of the tension band 7 is opposite to that of the specimen material 1. After the tension band 7 is wound, the second spring 8 is stretched and fixed by a ring 9 and a guide rod 10, so that the second spring 8 remains stretched during the test. The elastic force of the second spring 8 pulls the tension band 7 and makes the semicircular fixed wheel 6 also have a tendency to rotate, and the direction of the rotation tendency of the semicircular fixed wheel 6 is opposite to that of the semicircular roller clip 4, thereby offsetting a part of the force on the square protrusion 15, making the force between the square protrusion 15 and the inner wall of the limiting groove 12 smaller, thereby reducing the wear on the inner wall of the limiting groove 12.

[0052] Although the utility model has been described in detail above with general descriptions and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements can be made to the utility model. Therefore, these modifications or improvements made without departing from the spirit of the utility model are within the scope of protection claimed by the utility model.

Claims

1. A composite grid fabric tensile test device, used for testing a specimen material (1), comprising two symmetrically arranged clamping cavities (2), the two clamping cavities (2) being respectively arranged at two ends of the specimen material (1), characterized in that: Two symmetrical semicircular roller clamps (4) are arranged inside the clamping cavity (2); a corresponding end of the sample material (1) is clamped between the two semicircular roller clamps (4) and wrapped around the outer ends of the two semicircular roller clamps (4); Both sides of the clamping cavity (2) are provided with through grooves (11), the inner wall of the through grooves (11) is provided with limit grooves (12), and both ends of the semicircular roller clamp (4) are fixedly provided with square protrusions (15). In a test state, the two square protrusions (15) located on the same side extend to the outside of the clamping cavity (2) through the limit grooves (12) on the corresponding side, and the outer ends of the square protrusions (15) are in contact with the inner wall of the limit grooves (12); Both sides of the specimen material (1) are provided with fixing components (5), and the fixing components (5) are clamped on the outer ends of two square protrusions (15) on the corresponding side, and the two square protrusions (15) are clamped and fixed by the fixing components (5).

2. A composite grid fabric tensile test device according to claim 1, characterized in that: The semicircular roller clamp (4) is a solid semicircular high-strength steel bar, and a transverse scale (13) and a plurality of longitudinal scales (14) are embedded on the contact surface between the semicircular roller clamp (4) and the specimen material (1).

3. A composite grid fabric tensile test device according to claim 1, characterized in that: The fixing assembly (5) comprises a clamping plate (501), two square protrusions (15) on the corresponding side are both located inside the clamping plate (501), and grooves are formed on the sides of the two square protrusions (15) facing the inner wall of the clamping plate (501); A fastening bolt is provided on the rear side of the clamping plate (501) through a thread, and one end of the fastening bolt extends into a groove on the rear square protrusion (15).

4. A composite grid fabric tensile test device according to claim 3, characterized in that: The front side of the clamping plate (501) is provided with a scale rod (504), the rear end of the scale rod (504) extends into the interior of the clamping plate (501) and is fixedly provided with a push plate (502), the push plate (502) is in contact with the square protrusion (15) on the front side, and a limit block is fixedly provided on the push plate (502), and the limit block is located in a groove on the square protrusion (15) on the front side; A first spring (503) is fixedly provided on one side of the push plate (502) away from the square protrusion (15), and one end of the first spring (503) is fixedly connected to the inner wall of the clamping plate (501).

5. The composite grid fabric tensile test device according to claim 1, characterized in that: A ball joint hinge (3) is provided at one end of the clamping cavity (2) away from the specimen material (1), and the ball joint hinge (3) comprises a hemispherical shell (301) fixedly arranged on the clamping cavity (2), a ball joint (302) is provided inside the hemispherical shell (301), and an external connecting rod (303) extending to the outside of the hemispherical shell (301) is fixedly arranged at the top end of the ball joint (302).

6. A composite grid fabric tensile test device according to claim 1, characterized in that: A semicircular fixing wheel (6) is fixedly provided at one end of the square protrusion (15) away from the clamping cavity (2), and two semicircular fixing wheels (6) located on the same side of the clamping cavity (2) are symmetrically arranged.

7. A composite grid fabric tensile test device according to claim 6, characterized in that: A tension belt (7) is provided between two semicircular fixed wheels (6) located on the same side of the clamping cavity (2). The tension belt (7) is clamped and fixed by the two semicircular fixed wheels (6) and is wound around the outer ends of the two semicircular fixed wheels (6). The winding direction of the tension belt (7) is opposite to the winding direction of the specimen material (1).

8. A composite grid fabric tensile test device according to claim 7, characterized in that: A second spring (8) is fixedly provided at one end of the tension belt (7), a collar (9) is fixedly provided at one end of the second spring (8), a guide rod (10) is fixedly provided at a corresponding side of the clamping cavity (2), and the collar (9) is sleeved on the outer end of the guide rod (10).

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