Sample horizontal tensile stress strain gauge

Abstract

The utility model discloses a sample horizontal tensile stress strain gauge, which comprises a slide rail, a guide assembly, a clamp and a displacement meter, and is characterized in that the slide rail is mounted on a workbench; the guide assembly is installed on the sliding rail, and the hook assembly is fixed to one end of the guide assembly. One end of the clamp is connected with the motor through the hook assembly, and the other end of the clamp is connected with the tension meter; the clamp comprises two groups of end covers and cutting ring chucks which are symmetrically arranged from outside to inside, and a sample is placed between the two cutting ring chucks; the displacement meter is installed on the workbench and connected with the guide assembly. According to the sample horizontal tensile stress strain gauge, when a sample is prepared, the cylindrical sample and the cutting ring chuck are integrated, only the end cover of the sample needs to be screwed, and a special clamp is not needed; moreover, the prepared test piece is regular, the test result is accurate, the prepared test piece is good in coaxiality, and the eccentric error is greatly eliminated during stretching.

Description

Technical Field

[0001] This utility model belongs to the technical field of geotechnical testing equipment, specifically relating to a horizontal tensile stress-strain gauge for specimens. Background Technology

[0002] In general engineering design, the tensile strength of soil is relatively small compared to its compressive strength and is often neglected. However, in practical engineering applications, the tensile strength of soil is crucial. For example, in clay-core dams, the flexible clay core, compared to the relatively rigid coarse-grained soil shell, is prone to consolidation settlement over time. This leads to tensile stress at the top of the core wall due to the arching effect, creating a potential risk of cracking. In foundation splitting grouting design, the grouting pressure needs to be designed based on the tensile strength of the sample. Therefore, with technological advancements and rising engineering quality standards, the tensile strength parameter of soil is receiving increasing attention, and more and more engineering projects are conducting research in this area to inform engineering design and prevent engineering defects.

[0003] Some research institutions use the Brazilian splitting method to test the tensile strength of soil, but soil exhibits greater plastic deformation compared to building materials like brick and stone, making this method poorly applicable. Other institutions use triaxial strength derivation, but this method has several drawbacks. First, the triaxial testing equipment is expensive, and the method itself is complex. Second, the formula derivation is complex, and the calculated boundary conditions do not conform to engineering realities. Third, there is a lack of standardized equipment and testing methods; each institution has its own approach.

[0004] Previous studies have involved complex instruments and equipment, and non-standard experimental methods. Some research institutions have focused on the clamping and bonding of the two ends of strip-shaped samples, requiring the use of special fixtures, which makes the instrument structure complex and the operation inconvenient. Utility Model Content

[0005] To address the aforementioned problems, this invention proposes a horizontal tensile stress-strain gauge for specimens.

[0006] The specimen horizontal tensile stress-strain gauge of this application includes: a slide rail, which is mounted on a worktable; a guide assembly, which is mounted on the slide rail, and a hook assembly is fixed to one end of the guide assembly; a clamp, which is movably mounted on the guide assembly, with one end of the clamp connected to a motor via the hook assembly and the other end connected to a tension gauge; the clamp includes two sets of end caps and ring cutter chucks symmetrically arranged from the outside to the inside, and the specimen is placed between the two ring cutter chucks; and a displacement gauge, which is mounted on the worktable and connected to the guide assembly.

[0007] The slide rail includes an upper slide rail plate and a lower slide rail plate that are slidably connected. The lower slide rail plate is fixed on the worktable. The upper slide rail plate is fixedly connected to the guide assembly. Two V-shaped grooves are symmetrically arranged on both sides of the top of the lower slide rail plate. Multiple steel balls are placed in the V-shaped grooves and separated from each other by steel ball guide plates. The upper slide rail plate and the lower slide rail plate are slidably connected by steel balls.

[0008] The guide assembly includes a base plate fixedly connected to the slide rail. Both ends of the base plate are provided with baffles. Two slide rods are provided on the base plate along its length. The angle between the line connecting the axis of the slide rod and the axis of the clamp and the direction of the plumb bob is 30°.

[0009] The baffle at the end closest to the motor has a downward recess in the middle to form a groove, and a hook assembly is fixed in the groove. The hook assembly is set perpendicular to the baffle.

[0010] The hook assembly is U-shaped, with hooks at both ends, and the middle position of the hook assembly is fixed in the groove of the baffle.

[0011] Of the two end caps of the clamp, a clamp hanging ring is fixedly connected to the outside of one end cap, and a tension gauge clip is fixedly connected to the outside of the other end cap. One end of the clamp is connected to a hook in the hook assembly through the clamp hanging ring, and the other end is connected to the tension gauge through the tension gauge clip.

[0012] The push rod of the motor is fixed with a motor connector, and the end of the motor connector is connected to a motor hanging ring. The motor hanging ring is connected to another hook in the hook assembly.

[0013] The output end of the tension gauge is fixed with a tension gauge connector, which is connected to the tension gauge clip in the fixture.

[0014] The clamp further includes a fixing element and a clamp. The fixing element is a ring composed of three identical arc plates that can be detached. The inner wall of the clamp matches the outer wall of the fixing element.

[0015] The clamp has an external thread at one end of the ring cutter chuck and an internal thread at the end of the end cap facing the ring cutter chuck. The end cap and the ring cutter chuck are connected by threads. The ring cutter chuck and the fixed sample are connected by a clamp. The two ends of the arc plate are inclined inward with bevels. The end of the ring cutter chuck facing the arc plate has an outwardly extending boss. When the ring cutter chuck is connected to the fixed sample, the bevels and the boss cooperate.

[0016] The beneficial effects of this utility model are:

[0017] 1) Convenient sample preparation. The end caps and ring cutter chucks in the fixture are connected by threads, and the ring cutter chucks are connected to the sample holder by clamps, which allows for the disassembly and assembly of the fixture. The fixture can be assembled into a cylindrical shape before the sample is loaded. The sample diameter conforms to the conventional dimensions of geotechnical testing and can effectively utilize existing tools.

[0018] 2) No special fixtures are required. During sample preparation, the cylindrical specimen and the ring cutter chuck are integrated. Simply screw on the specimen end cap; no special fixtures are needed.

[0019] 3) The specimens are prepared in a regular manner, resulting in accurate test results. The prepared specimens have good coaxiality, which greatly eliminates eccentricity errors during tensile testing.

[0020] 4) Automatic control, simple and quick testing. After the system parameters are set, the test can be completed with one click through the controller. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of this utility model.

[0022] Figure 2 This is a schematic diagram showing the connection between the fixture and the sample of this utility model.

[0023] Figure 3 This is a schematic diagram of the fixture of this utility model when loading the sample.

[0024] Figure 4 This is an exploded view of the fixture of this utility model.

[0025] Figure 5 This is a schematic diagram of the structure of the guide component of this utility model.

[0026] Figure 6 This is a diagram showing the positional relationship between the slide bar and the clamp of this utility model.

[0027] Figure 7 This is a schematic diagram of the slide rail of this utility model.

[0028] Figure 8 This is a side view of the present invention.

[0029] Figure label:

[0030] Workbench 1; Displacement gauge 2; Magnetic base 201; Slide rail 3; Upper slide rail plate 301; Lower slide rail plate 302; Steel ball 303; Steel ball guide plate 304; Tension gauge 4; Tension gauge connector 401; Guide assembly 5; Hook 501; Baffle 502; Base plate 503; Slide rod 504; Sample 6; Fixture 7; Fixture hanging ring 701; Tension gauge clip 702; End cap 703; Ring cutter chuck 704; Sample fixing component 705; Clamp 706; Motor 8; Motor connector 801; Motor hanging ring 802. Detailed Implementation

[0031] The embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0032] like Figures 1-8 As shown, the specimen horizontal tensile stress strain gauge of this application includes: a slide rail 3, a guide assembly 5, a clamp 7, a motor 8, a force gauge 4, and a displacement gauge 2. The slide rail 3 is mounted on the worktable 1 and can slide relative to the worktable 1. The guide assembly 5 is mounted on the slide rail 3 and can move with the slide rail 3. A hook assembly is fixed to one end of the guide assembly 5. The clamp 7 is movably mounted on the guide assembly 5. One end of the clamp 7 is connected to the motor 8 through the hook assembly, and the other end is connected to the force gauge 4. The clamp 7 can move relative to the guide assembly 5. When the motor 8 pulls one end of the clamp 7, the force gauge 4 at the other end of the clamp 7 will display data. The clamp 7 includes two sets of end caps 703 and ring cutter chucks 704 arranged symmetrically from the outside to the inside. The specimen 6 is placed between the two ring cutter chucks 704. The displacement gauge 2 is mounted on the worktable 1 and is connected to the guide assembly 5. When the guide assembly 5 moves with the motor 8 through the hook 501, the displacement gauge 2 will display the moving distance of the guide assembly 5.

[0033] like Figure 7 As shown, the slide rail 3 includes a slidingly connected upper slide rail plate 301 and a lower slide rail plate 302. The lower slide rail plate 302 is fixed to the worktable 1 by bolts, and the upper slide rail plate 301 is fixedly connected to the guide assembly 5 by bolts. Therefore, when the guide assembly 5 moves, it will drive the upper slide rail plate 301 to move relative to the lower slide rail plate 302. Two V-shaped grooves are symmetrically arranged on both sides of the top of the lower slide rail plate 302. Multiple steel balls 303 are placed in the V-shaped grooves, and the steel balls 303 are separated by steel ball guide plates 304. The upper slide rail plate 301 and the lower slide rail plate 302 move relative to each other through the rolling of the steel balls 303. Each end of the two V-shaped grooves has a small nail to prevent the steel balls 303 from slipping out.

[0034] like Figure 5 As shown, the guide assembly 5 includes a base plate 503 fixedly connected to the slide rail upper plate 301 by bolts or adhesive. Both ends of the base plate 503 are provided with baffles 502. Two slide rods 504 are arranged along the length of the base plate 502, and the two slide rods 504 are parallel to each other. A clamp 7 is located on the slide rods 504 and is movable along the slide rods 504. Figure 6As shown, the angle between the line connecting the axis of slide bar 504 and the axis of clamp 7 and the direction of the plumb bob is 30° to ensure stable clamp placement and reduce friction during sliding. Because clamp 7 and slide bar 504 are in tangential contact with each other, the contact area is very small, so the friction is very small when running horizontally. If it is necessary to further reduce the friction, the surface smoothness of the clamp material can be improved or lubricating oil can be applied.

[0035] The height of the baffle 502 near the motor 8 is higher than the height of the baffle at the other end.

[0036] The baffle 502 near the motor 8 has a recessed groove in the middle, and a hook assembly is fixed in the groove. The hook assembly is set perpendicular to the baffle 502.

[0037] The hook assembly is U-shaped, with hooks 501 at both ends, and the middle position of the hook assembly is fixed in the groove of the baffle 502.

[0038] like Figures 2-4 As shown, the clamp 7 includes an end cap 703, a ring cutter chuck 704, a clamp 706, a sample fixing component 705, a clamp hanging ring 701, and a force gauge clamp 702. There are two end caps 703, two ring cutter chucks 704, and two clamps 706. One end cap 703 is fixedly connected to the clamp hanging ring 701 on its outer side, and the other end cap 703 is fixedly connected to the force gauge clamp 702 on its outer side. One end of the clamp 7 is connected to a hook 501 in the hook assembly via the clamp hanging ring 701, and the other end of the clamp 7 is connected to a force gauge 4 via the force gauge clamp 702. The other hook 501 in the hook assembly is connected to a motor 8. The outer center of both end caps 703 has a downward-recessed internal thread, and the end of the clamp hanging ring 701 has an outward-protruding external threaded rod. The clamp hanging ring 701 is threadedly connected to the end caps 703 of the clamp 7. The end of the force gauge clamp 702 also has an outwardly protruding external threaded rod, and the force gauge clamp 702 and the end cap 703 are also connected by threads.

[0039] The fixed sample 705 is a ring composed of three identical arc pieces spliced ​​together. The three arc pieces are combined together by a clamp 706 to form a ring. When the clamp 706 is removed, the three arc pieces can be separated. When combined, the inner wall of the clamp 706 matches the outer wall of the fixed sample 705.

[0040] The ring cutter chuck 704 in the fixture 7 has an external thread at one end, and the end cap 703 facing the ring cutter chuck 704 has an internal thread. The end cap 703 and the ring cutter chuck 704 are connected by threads. The ring cutter chuck 704 is connected to the fixed sample 705 by a clamp 706. The two ends of the arc plate are inclined inward with bevels. The end of the ring cutter chuck 704 facing the arc plate has an outwardly extending boss. When the ring cutter chuck 704 is connected to the fixed sample 705, the bevels and the boss cooperate.

[0041] During sample preparation, leave one end cap 703. First, connect a set of ring cutter chucks 704 of fixture 7 to one end cap 703 by thread. Then, use clamps 706 to connect three arc plates to the ring cutter chucks 704 on both sides to form a cylindrical shape, i.e., fixture cylinder. Compact the sample into the fixture cylinder in layers according to the given moisture content and density, with the surface flush with the top opening. Finally, close the other end cap 703.

[0042] Once the sample preparation is complete, place the prepared sample clamp 7 vertically on the workbench 1, tighten the other end cap 703, gently screw on the clamp hanging ring 701, remove the three arc pieces to expose the sample, hold the clamp 7 upright by hand and hold the lower end, gently screw on the tension gauge clip 702, remove the clamp 706, and then place the clamp 7 horizontally on the guide assembly 5.

[0043] Motor 8 is fixed on workbench 1. The push rod of motor 8 is coaxial with the sample in the fixture. A motor connector 801 is provided at the push rod of motor 8. The end of motor connector 801 is threadedly connected to motor hanging ring 802. The hook 501 of the hook assembly is connected to motor connector 801 through motor hanging ring 802. A tension gauge connector 401 is provided at the output end of tension gauge 4. Tension gauge connector 401 is engaged with tension gauge clamp 702 at the end of fixture 7. A circular chuck is provided at the end of tension gauge connector 401. A groove that mates with the circular chuck is provided at the end of tension gauge clamp 702. Tension gauge connector 401 and tension gauge clamp 702 are detachably connected through the circular chuck and the groove.

[0044] Displacement gauge 2 is mounted on workbench 1 via magnetic base 201. The pointer of displacement gauge 2 is parallel to the direction of movement, and the pointer of displacement gauge 2 is in contact with baffle 502 of guide assembly 5. During the tensile test, the distance moved by guide assembly 5 is recorded by displacement gauge 2, which is the tensile deformation data of the specimen. The tensile deformation of the specimen can also be displayed in real time through servo motor parameters, motor push rod stroke and lead.

[0045] The force gauge 4 is fixed on the worktable 1. The force is measured by a digital force gauge, accurate to 0.01N, which can collect the peak force and export the force time-history curve. When the head end of the fixture 7 moves with the guide component 5, the generated force is measured in real time by the force gauge 4 fixed at the tail end of the fixture 7.

[0046] Motor 8 is controlled by a controller via a built-in digital power supply and adapter. The movement speed can be set according to test requirements.

[0047] The controller's internal parameters include servo motor parameters, the stroke and lead of the motor push rod. The system zero point is the zero position and maximum stroke of the motor push rod, designated as "Position 1" and "Position 2" respectively. The maximum stroke position count is set to 10000, which determines the real-time position of the motor push rod. The system's push-pull working range is "Position 1" and "Position 2". The system is set with two operating modes: "jog" and "automatic". Within the working range of "Position 1" and "Position 2", tensile tests are performed on the specimen according to the required movement direction and operating speed.

[0048] The workbench 1 is also equipped with a control panel, which is connected to the controller. The control panel has two operating modes: "jog" and "automatic", as well as an operating range formed by "position 1" and "position 2". The operating speed and direction are adjustable, and the operating range is also adjustable.

[0049] The test procedure for the horizontal tensile stress-strain gauge is as follows:

[0050] 1) Zeroing. Power on the machine, press the up and down keys on the control panel to enter the page menu, select "Zeroing", the motor will run, find the zero point and maximum stroke of the motor push rod, and determine the real-time position of the motor push rod.

[0051] 2) Parameter settings. Set the "Position 1" and "Position 2" of the operating range; set the movement speed and loading rate of the "jog" mode and "run" mode respectively; other related settings.

[0052] 3) Turn on the force gauge. Adjust the "zero point" to make the "peak value" valid.

[0053] 4) Specimen installation. Place the clamp 7 containing the specimen horizontally on the slide rod 504 of the guide assembly 5; connect the connectors at both ends.

[0054] 5) Connect the displacement gauge. Zero the point.

[0055] 6) Tensile test. Depending on the operating mode, "jog" or "run", press the left and right keys to perform the tensile test until the specimen breaks off.

[0056] 7) Disassemble the specimen. After the test is completed, remove the clamp 7 and clean the specimen debris from the guide assembly 5. Unscrew the specimen end cap 703 from the ring cutter chuck 704 and remove the internal specimen.

[0057] 8) Repeat the next test. Insert the new fixture 7 and perform the test according to the above steps.

[0058] 9) Maintenance and upkeep. When not in use, place the motor push rod in the middle position and turn off the power. The tension gauge needs to be charged periodically if it is not used for a long time.

[0059] In the description of this utility model, it should be understood that the terms "center", "length", "thickness", "upper", "lower", "horizontal", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0060] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0061] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0062] In this utility model, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this utility model. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0063] Although the above embodiments have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions and variations made to the above embodiments by those skilled in the art are within the protection scope of the present invention.

Claims

1. A specimen level tensile stress strain gauge characterized by, The utility model provides a kind of tensile testing machine, including: Sliding rail, the sliding rail is installed on workbench; Guide assembly, the guide assembly is installed on sliding rail, one end of guide assembly is fixed with hook assembly; Clamp, clamp is movably arranged on guide assembly, one end of clamp is connected motor through hook assembly, and other end is connected tensile tester;The clamp includes two groups of end cover and ring cutter chuck that are symmetrically arranged from outside to inside, and sample is placed between two ring cutter chucks; Displacement meter, the displacement meter is installed on workbench, and displacement meter is connected with guide assembly.

2. The specimen horizontal tensile stress-strain instrument of claim 1, wherein, The sliding rail includes slidingly connected sliding rail upper disc and sliding rail lower disc, and the sliding rail lower disc is fixed on the workbench, and the sliding rail upper disc is fixedly connected with the guide assembly, and two V-shaped grooves are symmetrically arranged on the top of the sliding rail lower disc, a plurality of steel balls are placed in the V-shaped grooves, the plurality of steel balls are separated by steel ball guide pieces, and the sliding rail upper disc and the sliding rail lower disc are slidingly connected by the steel balls.

3. The specimen horizontal tensile stress-strain instrument of claim 1, wherein, The guide assembly includes a bottom plate fixedly connected with the sliding rail, baffles are arranged at both ends of the bottom plate, two sliding rods are arranged on the bottom plate along the length direction of the bottom plate, the clamp is placed on the sliding rods, and the included angle between the axis of the sliding rod and the axis of the clamp and the direction of the plumb line is 30°.

4. The specimen horizontal tensile stress-strain instrument of claim 3, wherein, The middle of the baffle near the motor is recessed downward to form a groove, and the hook assembly is fixed in the groove, and the hook assembly is perpendicular to the baffle.

5. The specimen horizontal tensile stress-strain instrument of claim 4, wherein, The hook assembly is U-shaped, hooks are arranged at both ends of the hook assembly, and the hook assembly is fixed in the groove of the baffle at the middle position.

6. The specimen horizontal tensile stress-strain instrument of claim 3, wherein, One of the two end covers of the clamp is fixedly connected with a clamp ring on the outside, the other end cover is fixedly connected with a tensile tester clamp on the outside, one end of the clamp is connected with one of the hooks of the hook assembly through the clamp ring, and the other end is connected with the tensile tester through the tensile tester clamp.

7. The specimen horizontal tensile stress-strain instrument of claim 6, wherein, The push rod of the motor is fixed with a motor connecting piece, the motor connecting piece is connected with a motor ring at the end, and the motor ring is connected with the other hook of the hook assembly.

8. The specimen horizontal tensile stress-strain instrument of claim 6, wherein, The output end of the tensile tester is fixed with a tensile tester connecting piece, and the tensile tester connecting piece is connected with the tensile tester clamp in the clamp.

9. The specimen horizontal tensile stress-strain instrument of claim 1, wherein, The clamp further includes a sample fixing member and a clamp, the sample fixing member is a circular ring composed of three identical circular arc pieces, and the inner wall of the clamp is matched with the outer wall of the sample fixing member.

10. The specimen horizontal tensile stress-strain instrument of claim 9, wherein, One end of the ring cutter chuck in the clamp is provided with external threads, the end of the end cover towards the ring cutter chuck has internal threads, the end cover and the ring cutter chuck are connected through threads, the ring cutter chuck and the sample fixing member are connected through the clamp, the two ends of the circular arc piece are inwardly inclined with inclined surfaces, the end of the ring cutter chuck towards the circular arc piece has a convex boss extending outward, and the inclined surface and the convex boss are matched when the ring cutter chuck is connected with the sample fixing member.

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