High-precision dog bone test piece tensile experiment device

Abstract

The utility model belongs to the technical field of civil construction, and particularly relates to a high-precision dog bone test piece tensile experiment device which comprises an upper placement plate and a lower placement plate, an upper placement groove is formed in the upper placement plate, notches are formed in the two sides of the upper placement plate, L-shaped plates are fixedly arranged on the two sides of the upper placement plate, and the lower placement plate is fixedly arranged on the lower placement plate. The long end of the L-shaped plate is perpendicular to the upper placement plate, the L-shaped plate is fixedly connected with a shell of a displacement meter through a bolt, the shell of the displacement meter is clamped between the L-shaped plate and the upper surface of the upper placement plate, and an ejector rod of the displacement meter penetrates through the notch to be fixedly connected with the lower placement plate. The displacement meter is clamped between the upper placement plate and the L-shaped plate, and the displacement meter is limited and fixed through the placement plate and the L-shaped plate, so that the stability of the displacement meter is ensured.

Description

Technical Field

[0001] This utility model belongs to the field of civil engineering and construction technology, and specifically relates to a high-precision tensile testing device for dog bone specimens. Background Technology

[0002] Concrete, as one of the most important materials in modern civil engineering structures, is a multiphase composite material with a highly complex failure mechanism. Concrete has relatively weak tensile strength, making its tensile properties one of the most crucial mechanical properties. Currently, the uniaxial tensile test on dog-bone specimens is a commonly used test for measuring the tensile strength of concrete. This test can easily determine the stress-strain relationship of concrete and accurately reflect its tensile strength. However, in existing uniaxial tensile testing apparatuses for dog-bone specimens, the displacement gauge clamps are fixed to the dog-bone specimen, which is prone to relative slippage and stress concentration, leading to inaccurate displacement-strain calculations. Furthermore, it is difficult to determine whether the plane at the variable cross-section of the dog-bone specimen is perpendicular to the displacement gauge's measuring line, also resulting in inaccurate strain measurements. In addition, the displacement gauge must be re-fixed each time the dog-bone specimen is changed, making it impossible to guarantee that the upper and lower clamps of the displacement gauge clamp remain horizontally parallel during each installation. This significantly increases the operational difficulty and cannot guarantee the accuracy of strain measurements. Finally, the displacement gauge is fixed at a single point, which is difficult to keep stationary during actual tensile tests, causing the displacement gauge to wobble back and forth and side to side, thus leading to inaccurate measurement data. There is a lack of a high-precision tensile testing device for dog bone specimens in the existing technology. Utility Model Content

[0003] This invention provides a high-precision tensile testing device for dog bone specimens to address the above-mentioned problems.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A high-precision tensile testing device for dog bone specimens includes an upper clamp and a lower clamp, which are respectively clamped at both ends of a dog bone specimen. The upper and lower clamps are fixedly connected to the fixed end and tensile end of a universal tensile testing machine, respectively. The device also includes an upper mounting plate and a lower mounting plate. An upper mounting groove is formed on the upper mounting plate, and the upper clamp is fixedly connected to the upper mounting groove. An upper clamp is bolted into the upper mounting groove, thereby limiting the movement of the dog bone specimen and preventing it from breaking off from the specimen. One side of the fixture extends out, and a lower mounting groove is provided on the lower mounting plate. A lower clamping plate is fixedly connected to the lower mounting groove by bolts. The lower mounting plate is clamped onto the dog bone specimen by cooperating with the lower clamping plate. Notches are provided on both sides of the upper mounting plate. L-shaped plates are fixedly installed on both sides of the upper mounting plate. The long end of the L-shaped plate is perpendicular to the upper mounting plate. The displacement gauge housing is fixedly connected to the L-shaped plate by bolts. The displacement gauge housing is clamped between the L-shaped plate and the upper surface of the upper mounting plate. The displacement gauge's push rod passes through the notch and is fixedly connected to the lower mounting plate.

[0006] Furthermore, tubular levels are provided on both the upper and lower mounting plates.

[0007] Furthermore, the two displacement gauges are symmetrically arranged on both sides of the upper mounting plate.

[0008] Compared with the prior art, the present invention has the following advantages:

[0009] This utility model fixes the upper clamp, upper mounting plate and L-shaped plate of the specimen, and fixes the displacement meter between the upper mounting plate and the L-shaped plate. After the displacement meter is installed, it does not need to be reinstalled when the dog bone specimen is replaced, which improves the experimental efficiency. At the same time, it helps to ensure the horizontal state of the upper mounting plate and the perpendicularity of the displacement meter measuring line to the variable cross-section plane of the dog bone specimen, thereby ensuring the accuracy of the measurement experimental data.

[0010] In this invention, the displacement gauge is mounted between the upper mounting plate and the L-shaped plate. The mounting plate and the L-shaped plate limit and fix the displacement gauge, which helps to ensure the stability of the displacement gauge.

[0011] This invention fixes the upper mounting plate to the upper clamp of the specimen, so that it does not come into contact with the dog bone specimen. This avoids the upper mounting plate from generating additional gravity, stress concentration and friction on the dog bone specimen, thus improving the accuracy of the experiment. The lower mounting plate and the lower clamp are fixedly clamped at the lower cross section of the dog bone specimen, which can accurately measure the displacement of the specimen and distinguish it from the displacement of the cross beam of the testing machine, thus improving the accuracy of the experiment.

[0012] In this invention, an upper clamping plate is fixedly connected to the upper mounting plate by bolts. However, the upper clamping plate and the upper mounting plate do not exert clamping force on the dog bone specimen. They only limit the dog bone specimen to prevent it from running out from one side of the clamping plate after being pulled apart and subjected to sudden changes in force.

[0013] This utility model has tubular leveling instruments on both the upper and lower mounting plates to detect whether they are on the horizontal line. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of this utility model;

[0015] In the figure, there is an upper clamp for the specimen, a lower clamp for the specimen, a dog bone specimen, an upper mounting plate, a lower mounting plate, an upper mounting groove, an upper clamping plate, a lower mounting groove, a lower clamping plate, a notch, an L-shaped plate, a displacement gauge, and a tubular level. Detailed Implementation

[0016] To further illustrate the technical solution of this utility model, the following embodiments will be used to further explain this utility model.

[0017] like Figure 1 As shown, a high-precision tensile testing device for dog bone specimens includes an upper specimen clamp 1 and a lower specimen clamp 2, which are respectively clamped at both ends of a dog bone specimen 3. The upper specimen clamp 1 and the lower specimen clamp 2 are fixedly connected to the fixed end and tensile end of a universal tensile testing machine, respectively. The device also includes an upper mounting plate 4 and a lower mounting plate 5. An upper mounting groove 6 is formed on the upper mounting plate 4. The upper specimen clamp 1 is fixedly connected to the upper mounting groove 6 of the upper mounting plate 4. An upper clamping plate 7 is fixedly connected to the upper mounting groove 6 by bolts. The upper clamping plate 7 limits the movement of the dog bone specimen 3, preventing it from breaking off from the upper specimen clamp 1. A lower mounting plate 5 has a lower mounting groove 8 on one side, and a lower clamping plate 9 is fixedly connected to the lower mounting groove 8 by bolts. The lower mounting plate 5 is clamped onto the dog bone specimen 3 by cooperating with the lower clamping plate 9. A notch 10 is provided on both sides of the upper mounting plate 4, and an L-shaped plate 11 is fixedly installed on both sides of the upper mounting plate 4. The long end of the L-shaped plate 11 is perpendicular to the upper mounting plate 4. The L-shaped plate 11 is fixedly connected to the housing of the displacement gauge 12 by bolts. The housing of the displacement gauge 12 is clamped between the L-shaped plate 11 and the upper surface of the upper mounting plate 4. The top rod of the displacement gauge 12 passes through the notch 10 and is fixedly connected to the lower mounting plate 5. Two displacement gauges 12 are symmetrically arranged on both sides of the upper mounting plate 4. A tubular level 13 is provided on both the upper mounting plate 4 and the lower mounting plate 5.

[0018] The foregoing has shown and described the main features and advantages of this utility model. It will be apparent to those skilled in the art that this utility model 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 utility model. Therefore, the embodiments should be considered exemplary and non-limiting in all respects. The scope of this utility model is defined by the appended claims rather than the foregoing description, and thus all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this utility model.

[0019] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A high-precision tensile testing device for dog bone specimens, comprising an upper specimen clamp (1) and a lower specimen clamp (2), wherein the upper specimen clamp (1) and the lower specimen clamp (2) are respectively clamped at both ends of a dog bone specimen (3), and the upper specimen clamp (1) and the lower specimen clamp (2) are respectively fixedly connected to the fixed end and the tensile end of a universal tensile testing machine, characterized in that: It also includes an upper mounting plate (4) and a lower mounting plate (5). An upper mounting groove (6) is provided on the upper mounting plate (4). The specimen clamp (1) is fixedly connected to the upper mounting groove (6) of the upper mounting plate (4). An upper clamp (7) is fixedly connected in the upper mounting groove (6) by bolts. The upper clamp (7) is used to limit the dog bone specimen (3) and prevent the dog bone specimen (3) from breaking and running out from one side of the specimen clamp (1). A lower mounting groove (8) is provided on the lower mounting plate (5). A lower clamp (9) is fixedly connected in the lower mounting groove (8) by bolts. The mounting plate (5) is clamped onto the dog bone specimen (3) by cooperating with the lower clamping plate (9). Notches (10) are provided on both sides of the upper mounting plate (4). L-shaped plates (11) are fixedly installed on both sides of the upper mounting plate (4). The long end of the L-shaped plate (11) is perpendicular to the upper mounting plate (4). The L-shaped plate (11) is fixedly connected to the housing of the displacement gauge (12) by bolts. The housing of the displacement gauge (12) is clamped between the L-shaped plate (11) and the upper surface of the upper mounting plate (4). The top rod of the displacement gauge (12) passes through the notch (10) and is fixedly connected to the lower mounting plate (5).

2. The high-precision tensile testing device for dog bone specimens according to claim 1, characterized in that: Tubular level (13) is provided on both the upper mounting plate (4) and the lower mounting plate (5).

3. The high-precision tensile testing device for dog bone specimens according to claim 1, characterized in that: The two displacement gauges (12) are symmetrically arranged on both sides of the upper mounting plate (4).

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