Fixture for tensile test of fiber reinforced cement-based material

Abstract

The utility model relates to the technical field of tensile testing of fiber reinforced cement-based materials, and discloses a clamp for tensile testing of fiber reinforced cement-based materials, which comprises an upper clamping head and an upper end fixing block, a first fixing cover is sleeved outside the upper clamping head, and a first fixing shell is arranged at the bottom end of the upper clamping head. According to the clamp for the tensile test of the fiber-reinforced cement-based material, by arranging parts such as the gear, an operator is allowed to accurately control the clamping force of the clamp, so that a more stable and safer clamping process is realized, and a fixing block can automatically or manually adjust a clamping or loosening state according to the size and material condition of a test piece; therefore, the test piece can be prevented from being damaged in the mounting process, the fixture is particularly suitable for test pieces made of fragile materials or different in size, the precision of a tensile test is effectively improved, the risk that the test piece slides or is not uniformly stressed due to improper adjustment of the fixture is reduced, and the problem that flexible adjustment cannot be performed according to the actual size and material of the test piece is solved.

Description

Technical Field

[0001] This utility model relates to the field of tensile testing technology for fiber-reinforced cementitious materials, specifically a fixture for tensile testing of fiber-reinforced cementitious materials. Background Technology

[0002] Fiber-reinforced cementitious materials are a new type of high-strength, high-toughness building material. They possess excellent tensile strength and deformation capacity, and are widely used in the reinforcement, repair, and strengthening of reinforced concrete structures, making these otherwise fragile structures more robust and reliable. Research on their tensile strength and related parameters has always been a key focus in the field of engineering safety. Laboratory tensile testing of cementitious materials is the primary means of obtaining their tensile performance parameters, and the accuracy of the results directly affects the safety of cementitious materials in practical engineering applications.

[0003] In laboratory tensile tests, traditional clamps typically use a direct clamping method to fix the specimen within the clamp. This direct placement of the specimen often results in uneven clamping force due to variations in specimen size, potentially causing damage during clamping, or even localized damage or stress concentration. Furthermore, existing clamps usually lack adjustment mechanisms for the clamping process; the clamping or loosening force cannot be flexibly adjusted according to the actual size and material of the specimen, which can adversely affect the test results.

[0004] Now, a novel fixture for tensile testing of fiber-reinforced cementitious materials is proposed to solve the above problems. Utility Model Content

[0005] The purpose of this invention is to provide a clamp for tensile testing of fiber-reinforced cement-based materials, so as to solve the problem mentioned in the background art that it is not convenient to quickly limit and fix the patient's body.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a clamp for tensile testing of fiber-reinforced cementitious materials, comprising an upper clamping head and an upper fixing block. A first fixing cover is sleeved on the outside of the upper clamping head. A first fixing shell is provided at the bottom end of the upper clamping head. The bottom end of the upper clamping head penetrates the interior of the first fixing shell and is fixedly connected to a first circular seat. A first gear is fixedly connected to the bottom end of the outside of the upper clamping head. First handles are fixedly connected to both sides of the upper clamping head. First reserved grooves are provided on both sides of the first fixing cover. The first fixed shell has upper fixed blocks on both sides, the lower clamping head has a lower clamping head at the bottom, a second fixed cover is sleeved on the outside of the lower clamping head, a second fixed shell is provided at the top of the lower clamping head, the top of the lower clamping head passes through the interior of the second fixed shell and is fixedly connected to a second round seat, a second gear is fixedly connected to the top of the outside of the lower clamping head, a second handle is fixedly connected to both sides of the lower clamping head, a second reserved groove is provided on both sides of the second fixed cover, and lower fixed blocks are provided on both sides of the second fixed shell.

[0007] As a further technical solution of this utility model, the bottom end of the first fixing cover is embedded inside the top of the first fixing shell, and one side of the first handle penetrates the interior of the first reserved groove.

[0008] As a further technical solution of this utility model, a first energy-absorbing stone is fixedly connected to the front end of the upper fixing block, and a first support frame is provided between the front ends of the first energy-absorbing stones.

[0009] As a further technical solution of this utility model, the upper fixing block is provided in two sets, the upper fixing block is distributed at the front end and the rear end of the first gear, and the upper fixing block meshes with the outside of the first gear.

[0010] As a further technical solution of this utility model, the top of the second fixing cover is embedded in the interior of the bottom of the second fixing shell, and one side of the second handle penetrates the interior of the second reserved groove.

[0011] As a further technical solution of this utility model, a second energy-absorbing stone is fixedly connected to the rear end of the lower fixing block, and a second support frame is provided between the rear ends of the second energy-absorbing stone.

[0012] As a further technical solution of this utility model, a stress-reducing pad is fixedly connected to the top of one side of the lower fixing block.

[0013] As a further technical solution of this utility model, two sets of lower fixing blocks are provided, which are distributed at the front end and rear end of the second gear, and the lower fixing blocks mesh with the outside of the second gear.

[0014] Compared with the prior art, the beneficial effects of this utility model are: the fixture for tensile testing of fiber-reinforced cement-based materials not only realizes the adjustment of the fixing block before specimen installation, effectively improving the accuracy of the tensile test, effectively preventing the specimen from deforming under stress, reducing experimental errors caused by specimen position offset, but also achieves an important stress reduction effect.

[0015] (1) By setting gears and other parts, the operator can precisely control the clamping force of the fixture, thereby achieving a more stable and safe clamping process. The fixing block can automatically or manually adjust the clamping or loosening state according to the size and material of the specimen. This can avoid damage to the specimen during installation. It is especially suitable for brittle materials or specimens of different sizes, effectively improving the accuracy of tensile testing and reducing the risk of specimen slippage or uneven force due to improper fixture adjustment.

[0016] (2) By setting up parts such as a magnetic support frame, the fixed block is firmly attracted by magnetic force, which can not only effectively prevent the specimen from deforming into shape when under force, but also prevent the specimen from shifting back and forth during the tension process. With the introduction of this magnetic reinforcement support frame, the specimen can maintain a more stable stress state in the experiment, reducing the experimental error caused by the displacement of the specimen position. Compared with the traditional fixing method, the magnetic support frame has higher flexibility and convenience, is simpler to operate, and does not require complicated mechanical devices during the adjustment process.

[0017] (3) By incorporating stress-reducing shims, the shims on the inner side of the fixture play a crucial role in stress reduction after the specimen is installed and clamped. Due to their excellent elasticity and buffering properties, the stress-reducing shims can absorb some stress and evenly distribute the clamping force during the tensile test, thereby reducing the impact of stress concentration on the specimen. Compared to traditional metal fixtures, stress-reducing shims not only effectively alleviate local stress at the clamping point but also absorb some of the vibration transmitted during the experiment, further protecting the integrity of the specimen. For brittle specimens, stress-reducing shims can significantly reduce the risk of breakage, ensuring the smooth conduct of the test. Attached Figure Description

[0018] Figure 1 This is a frontal cross-sectional view of the present invention.

[0019] Figure 2 This is a top view schematic diagram of the connection between the upper fixing block and the first gear of this utility model;

[0020] Figure 3 This is a side view of the connection between the first fixing cover and the first fixing shell of this utility model.

[0021] Figure 4This is a front view structural diagram of the connection between the first support frame and the upper fixing block of this utility model.

[0022] In the diagram: 1. Upper clamping head; 2. First fixing cover; 3. First reserved slot; 4. Second handle; 5. First fixing shell; 6. Upper fixing block; 7. First gear; 8. First round seat; 9. First energy-absorbing stone; 10. First support frame; 11. Lower clamping head; 12. Second fixing cover; 13. Second reserved slot; 14. Second handle; 15. Second fixing shell; 16. Lower fixing block; 17. Second gear; 18. Second round seat; 19. Second energy-absorbing stone; 20. Second support frame; 21. Stress-reducing pad. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0024] Please see Figure 1-4 This utility model provides an embodiment of a fixture for tensile testing of fiber-reinforced cementitious materials, comprising an upper clamping head 1 and an upper fixing block 6. A first fixing cover 2 is sleeved on the outside of the upper clamping head 1, and a first fixing shell 5 is provided at the bottom end of the upper clamping head 1. The bottom end of the upper clamping head 1 penetrates the interior of the first fixing shell 5 and is fixedly connected to a first round seat 8. A first gear 7 is fixedly connected to the bottom end of the outside of the upper clamping head 1. First handles 4 are fixedly connected to both sides of the upper clamping head 1. First reserved grooves 3 are provided on both sides of the first fixing cover 2, and first fixed shell 5 is provided on both sides. It has an upper fixing block 6, a lower clamping head 11 at the bottom of the upper clamping head 1, a second fixing cover 12 sleeved on the outside of the lower clamping head 11, a second fixing shell 15 at the top of the lower clamping head 11, a second round seat 18 fixedly connected to the top of the lower clamping head 11 through the interior of the second fixing shell 15, a second gear 17 fixedly connected to the top of the outside of the lower clamping head 11, a second handle 14 fixedly connected to both sides of the lower clamping head 11, a second reserved groove 13 on both sides of the second fixing cover 12, and a lower fixing block 16 on both sides of the second fixing shell 15.

[0025] The bottom end of the first fixed cover 2 is embedded inside the top of the first fixed shell 5, and one side of the first handle 4 penetrates the interior of the first reserved groove 3.

[0026] Two sets of upper fixing blocks 6 are provided, which are distributed at the front and rear ends of the first gear 7 and mesh with the outside of the first gear 7.

[0027] The top of the second fixing cover 12 is embedded inside the bottom of the second fixing shell 15, and one side of the second handle 14 penetrates the interior of the second reserved groove 13;

[0028] Two sets of lower fixing blocks 16 are provided, which are distributed at the front and rear ends of the second gear 17 and mesh with the outside of the second gear 17.

[0029] Specifically, such as Figure 1 , Figure 2 and Figure 3 As shown, the built-in gear rotation structure allows for flexible adjustment of the rotating handle according to the size and material of the specimen, enabling it to clamp or loosen the fixing blocks. In actual operation, it is not necessary to directly insert the specimen into the fixture. Instead, by turning the first handle 4 and the second handle 14, the upper fixing block 6 and the lower fixing block 16 are first adjusted to the loose state. After inserting the specimen, the first gear 7 and the second gear 17 are rotated to gradually clamp it, ensuring that the specimen is evenly clamped and avoiding damage caused by over-clamping. The upper clamping head 1 and the lower clamping head 11 adopt a threaded structure to connect to the tensile testing machine to increase friction and ensure effective force transmission.

[0030] The front end of the upper fixing block 6 is fixedly connected to the first energy-absorbing stone 9, and the front ends of the first energy-absorbing stone 9 are provided with a first support frame 10.

[0031] The rear end of the lower fixing block 16 is fixedly connected to the second energy-absorbing stone 19, and the rear end of the second energy-absorbing stone 19 is provided with a second support frame 20.

[0032] Specifically, such as Figure 1 and Figure 4 As shown, the magnetic suction structure effectively prevents the specimen from deforming or shifting forward or backward when subjected to tension. The reinforced support frame of the magnetic suction structure not only enhances the stability of the fixing block but also further improves the vibration resistance of the fixture, preventing the specimen from shifting position due to excessive tension. Compared with the traditional mechanical fixing method, this magnetic suction structure has better flexibility and stability, allowing the fixture to quickly adapt to different experimental conditions, reducing installation and adjustment time, and ensuring that the test results are not affected by the loosening of the clamping device, thus guaranteeing the efficiency and accuracy of the experiment.

[0033] A stress-reducing pad 21 is fixedly connected to the top of one side of the lower fixing block 16;

[0034] Specifically, such as Figure 1As shown, the stress-reducing pad 21, made of rubber, possesses excellent elasticity and cushioning properties, effectively reducing the impact of stress concentration on the specimen during clamping. This pad acts as a buffer during tensile testing, ensuring more uniform stress distribution on the specimen under tension, reducing localized damage caused by uneven clamping forces. Furthermore, the stress-reducing pad 21 can absorb some vibrations from the testing equipment, further protecting the integrity of the specimen.

[0035] Working Principle: In use, this invention firstly utilizes a built-in gear rotation structure to flexibly adjust the rotating handle according to the specimen's size and material, tightening or loosening the fixing blocks. In actual operation, the specimen does not need to be directly inserted into the clamp. Instead, by turning the first handle 4 and the second handle 14, the upper fixing block 6 and the lower fixing block 16 are first adjusted to a loose state. After inserting the specimen, the first gear 7 and the second gear 17 are rotated to gradually tighten the clamp, ensuring even clamping and preventing damage caused by over-clamping. The upper clamping head 1 and the lower clamping head 11 employ a threaded structure to connect to the tensile testing machine, increasing friction and ensuring effective force transmission. Finally, a magnetic suction structure is used to effectively... To prevent the specimen from deforming or shifting under tension, the reinforced support frame with a magnetic attraction structure not only enhances the stability of the fixing block but also further improves the vibration resistance of the clamp, preventing the specimen from shifting due to excessive tension. This magnetic attraction structure offers better flexibility and stability compared to traditional mechanical fixing methods, allowing the clamp to quickly adapt to different experimental conditions, reducing installation and adjustment time, and ensuring that loose clamping devices do not affect test results, thus guaranteeing the efficiency and accuracy of the experiment. Finally, the stress-reducing pad 21, made of rubber, has good elasticity and cushioning properties, effectively reducing the impact of stress concentration on the specimen during clamping. This pad acts as a buffer during tension, making the specimen more evenly stressed under tension, reducing local damage caused by uneven clamping force. Simultaneously, the stress-reducing pad 21 can also absorb some vibration from the testing equipment, further protecting the integrity of the specimen.

[0036] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A fixture for tensile testing of fiber reinforced cementitious materials, comprising an upper clamping head (1) and an upper end block (6), characterized in that: The outer sleeve of the upper clamping head (1) is provided with a first fixed cover (2), the bottom end of the upper clamping head (1) is provided with a first fixed shell (5), the bottom end of the upper clamping head (1) penetrates the inside of the first fixed shell (5) and is fixedly connected with a first circular seat (8), the bottom end of the outer part of the upper clamping head (1) is fixedly connected with a first gear (7), both sides of the upper clamping head (1) are fixedly connected with a first handle (4), both sides of the first fixed cover (2) are provided with a first reserved slot (3), both sides of the first fixed shell (5) are provided with an upper end fixed block (6), the bottom end of the upper clamping head (1) is provided with a lower clamping head (11), the outer sleeve of the lower clamping head (11) is provided with a second fixed cover (12), the top end of the lower clamping head (11) is provided with a second fixed shell (15), the top end of the lower clamping head (11) penetrates the inside of the second fixed shell (15) and is fixedly connected with a second circular seat (18), the top end of the outer part of the lower clamping head (11) is fixedly connected with a second gear (17), both sides of the lower clamping head (11) are fixedly connected with a second handle (14), both sides of the second fixed cover (12) are provided with a second reserved slot (13), both sides of the second fixed shell (15) are provided with a lower end fixed block (16).

2. The fixture for tensile testing of fiber reinforced cementitious materials according to claim 1, characterized in that: The bottom end of the first fixed cover (2) is embedded in the inside of the top end of the first fixed shell (5), one side of the first handle (4) penetrates the inside of the first reserved slot (3).

3. The fixture for tensile testing of fiber reinforced cementitious materials according to claim 1, wherein: The front end of the upper end fixed block (6) is fixedly connected with a first energy absorbing stone (9), and the first energy absorbing stone (9) is provided with a first support frame (10) between the front ends.

4. The fixture for tensile testing of fiber reinforced cementitious materials according to claim 1, wherein: The upper end fixed block (6) is provided with two groups, which are distributed at the front end and the rear end of the first gear (7), and the upper end fixed block (6) is engaged with the outside of the first gear (7).

5. The fiber reinforced cementitious material tensile test fixture of claim 1, wherein: The top end of the second fixed cover (12) is embedded in the inside of the bottom end of the second fixed shell (15), and one side of the second handle (14) penetrates the inside of the second reserved slot (13).

6. The fiber reinforced cementitious material tensile test fixture of claim 1, wherein: The rear end of the lower end fixed block (16) is fixedly connected with a second energy absorbing stone (19), and the second energy absorbing stone (19) is provided with a second support frame (20) between the rear ends.

7. The fiber reinforced cementitious material tensile test fixture of claim 1, wherein: The top end of one side of the lower end fixed block (16) is fixedly connected with a stress reduction gasket (21).

8. The fiber reinforced cementitious material tensile test fixture of claim 1, wherein: The lower end fixed block (16) is provided with two groups, which are distributed at the front end and the rear end of the second gear (17), and the lower end fixed block (16) is engaged with the outside of the second gear (17).

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