An in-situ self-reaction force testing device and method for transverse shear of pre-embedded channels

Abstract

This invention discloses an in-situ self-reaction force testing device and method for transverse shearing of pre-embedded channels. The device includes a reaction beam, two reaction fixed supports, two force transmission rods, a force sensor, a force transmission box, a sleeve, a displacement sensor, a connecting rod, and a force application mechanism. The sleeve is fixed to the shearing test point of the pre-embedded channel. The force transmission box is sleeved outside the sleeve. The force sensor is connected to the force transmission box and the connecting rod. The connecting rod is slidably connected to the reaction beam and fixedly connected to the force application mechanism, and is driven by the force application mechanism to move relative to the reaction beam. The two reaction fixed supports are symmetrically arranged on both sides of the shearing test point and fixedly connected to the pre-embedded channel. The two force transmission rods are symmetrically arranged on both sides of the connecting rod. One end of each force transmission rod is fixedly connected to the reaction beam, and the other end abuts against the pre-embedded channel. The displacement sensor is used to measure the movement distance of the transverse shearing test point. This testing device has a wide range of applications, few components, is easy to assemble and disassemble, is small in size and light in weight, and is easy to carry.

Description

Technical Field

[0001] This invention relates to a device for testing civil engineering, and more particularly to an in-situ self-reaction force testing device and method for transverse shear of pre-embedded channels. Background Technology

[0002] The transverse shear bearing capacity of embedded channels is an important mechanical indicator for embedded channels within concrete assemblies. In-situ testing of this capacity provides a more objective reflection of the mechanical properties of the embedded channels within the concrete assemblies. Currently, in-situ testing devices for the transverse shear bearing capacity of embedded channels mainly consist of a force application mechanism and a reaction mechanism. The reaction mechanism is primarily fixed to the assembly using expansion bolts or by erecting a separate reaction frame. Some non-in-situ testing devices simulate the actual use of embedded channels by fixing the channel separately to the instrument, and then applying shear force using a shear sleeve for testing.

[0003] The main problem with existing in-situ transverse shear testing devices for pre-embedded channels lies in the reaction mechanism: using expansion bolts to fix the reaction frame can cause permanent damage to the assembly. On the other hand, using a prefabricated reaction frame results in a large reaction frame itself, complicated installation procedures, and the method can only conduct in-situ tests on small assemblies, failing to meet the in-situ testing needs of large-volume or continuous assemblies.

[0004] In addition, the existing pre-embedded channel transverse shear test device is relatively large and bulky, and has very poor portability. Summary of the Invention

[0005] This invention provides an in-situ self-reaction force testing device and method for transverse shear of pre-embedded channels, which overcomes the shortcomings of the prior art described in the background art.

[0006] The technical solution adopted by this invention to solve its technical problem is:

[0007] An in-situ self-reaction force testing device for transverse shearing of a pre-embedded channel includes a self-reaction force module, a force application module, and a data acquisition module. The self-reaction force module includes a reaction beam, two reaction force fixed supports, and two force transmission rods. The force application module includes a force transmission box, a sleeve, a connecting rod, and a force application mechanism. The data acquisition module includes a force sensor and a displacement sensor. The central hole of the sleeve is aligned with the shearing test point, and the central axis of the sleeve is perpendicular to the pre-embedded channel. The sleeve and the pre-embedded channel are fixedly connected by a first bolt and a first nut placed at the shearing test point. The force transmission box is sleeved around the outer periphery of the sleeve. The two tension ends of the force sensor are respectively connected to the force transmission box and one end of the connecting rod. The other end of the connecting rod passes through the reaction beam and slides with it. The connecting rod is connected to the force-applying mechanism at one end, and the reaction beam is limited between the force-applying mechanism and the pre-embedded channel. The force-applying mechanism can drive the connecting rod and the reaction beam to move relative to each other, causing the connecting rod to move away from the shear test point. The line connecting the connecting rod, the two tension ends of the force sensor, and the shear test point is a straight line, and the straight line is perpendicular to the central axis of the sleeve and the pre-embedded channel. The two reaction fixed supports are symmetrically arranged on both sides of the shear test point and fixedly connected to the pre-embedded channel. The two force transmission rods are parallel to the connecting rod and symmetrically arranged on both sides of the connecting rod. One end of the two force transmission rods is fixedly connected to the reaction beam, and the other end abuts against the pre-embedded channel. The displacement sensor is used to measure the distance the transverse shear test point moves in the transverse shear direction.

[0008] In one embodiment, a polytetrafluoroethylene (PTFE) gasket is also included, which is placed between the force transmission box and the pre-embedded channel.

[0009] In one embodiment: each of the two reaction force fixing supports is provided with a blind hole, and the other end of the two force transmission rods is placed in the two blind holes and abuts against the blind end of the blind hole.

[0010] In one embodiment: each reaction force fixing support is fixedly connected to the pre-embedded channel by a number of second bolts and second nuts evenly spaced along the pre-embedded channel.

[0011] In one embodiment: the force sensor is an S-type force sensor.

[0012] In one embodiment: the first bolt is a T-bolt.

[0013] In one embodiment: the second bolt is a T-bolt.

[0014] In one embodiment: the force-applying mechanism includes a rotary operating wrench and a force-applying nut, the other end of the connecting rod is tapped with an external thread, the force-applying nut is screwed to the other end of the connecting rod and limits the reaction beam between the force-applying mechanism and the pre-embedded channel 100, and the rotary operating wrench is adapted to the force-applying nut.

[0015] In one embodiment: the force-applying mechanism is a through-hole hydraulic jack, which is connected to the other end of the connecting rod and abuts against the reaction beam.

[0016] An in-situ self-reactive force test method for transverse shear of a pre-embedded channel is provided, employing the aforementioned in-situ testing device. First, the entire in-situ testing device is pre-tightened by a force-applying mechanism to ensure tight contact between all components and eliminate any virtual displacement. Then, the connecting rod is pulled relative to the reaction beam by the force-applying mechanism, causing the shear test point of the pre-embedded channel to move. When the displacement sensor detects that the shear test point has moved to a set distance, the force-applying mechanism maintains a constant force applied to the connecting rod, and the force value measured by the force sensor is read, which is the transverse shear bearing capacity of the pre-embedded channel.

[0017] Compared with the prior art, this technical solution has the following advantages:

[0018] 1. The in-situ self-reaction force testing device described in this case can be directly installed on the combination of the pre-embedded channel and concrete to test the lateral bearing capacity of the pre-embedded channel. The test does not cause damage to the pre-embedded channel and concrete combination. The in-situ testing device is suitable for testing the lateral bearing capacity of pre-embedded channels in combinations with different shaped surfaces. It is not limited to planes, such as pre-embedded channels of shear walls, and can also be applied to segments with a specific curvature.

[0019] 2. The entire testing device has few components, a simple structure, a clear force transmission path, is easy to install and disassemble, and is small in size, light in weight, and easy to carry.

[0020] 3. The perforated PTFE gasket is placed between the force transmission box and the pre-embedded channel, which can effectively reduce the friction between the force transmission box, sleeve and the concrete surface of the assembly, and improve the test accuracy.

[0021] 4. The force is transmitted to the first bolt at the shear test point of the pre-embedded channel through the force transmission box and sleeve, which minimizes the concentrated stress and bending moment generated by the lateral tensile force on the first bolt during the shear test.

[0022] 5. Each reaction force fixing support is fixedly connected to the pre-embedded channel by several second bolts and second nuts evenly spaced along the pre-embedded channel, forming multiple fixing points between the reaction force fixing support and the pre-embedded channel, effectively dispersing the force transmitted to the pre-embedded channel through the reaction force fixing support during the test, and the reaction force is evenly distributed. Attached Figure Description

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0024] Figure 1 This is a schematic diagram of an in-situ self-reactive force testing device for transverse shearing of a pre-embedded channel.

[0025] Figure 2 This is a diagram illustrating the reaction force inside an in-situ self-reactive force testing device for transverse shearing of a pre-embedded channel. Detailed Implementation

[0026] Please refer to Figure 1 An in-situ self-reaction force testing device for transverse shearing of a pre-embedded channel includes a self-reaction force module, a force application module, and a data acquisition module. The self-reaction force module includes a reaction beam 1, two reaction force fixed supports 2, and two force transmission rods 3. The force application module includes a force transmission box 5, a sleeve 6, a connecting rod 8, and a force application mechanism 9. The data acquisition module includes a force sensor 4 and a displacement sensor 7. The central hole of the sleeve 6 is aligned with the shear test point, and the central axis of the sleeve 6 is perpendicular to the pre-embedded channel 100. The sleeve 6 and the pre-embedded channel 100 are fixedly connected by a first bolt 101 and a first nut 102 placed at the shear test point. The force transmission box 5 is sleeved around the outer periphery of the sleeve 6. The two tension ends of the force sensor 4 are respectively connected to the force transmission box 5 and one end of the connecting rod 8. The other end of the connecting rod 8 passes through the reaction beam 1 and is slidably connected to the reaction beam 1. The other end of the connecting rod 8 is connected to the force application mechanism 9, limiting the reaction beam 1 to the applied force. Between mechanism 9 and the pre-embedded channel 100, the force-applying mechanism 9 can drive the connecting rod 8 and the reaction beam 1 to move relative to each other, causing the connecting rod 8 to move away from the shear test point. The line connecting the connecting rod 8, the two tension ends of the force sensor 4, and the shear test point is a straight line, and this straight line is perpendicular to the central axis of the sleeve 6 and the pre-embedded channel 100. The two reaction fixing supports 2 are symmetrically arranged on both sides of the shear test point and are fixedly connected to the pre-embedded channel 100. The contact surface of the reaction fixing support and the pre-embedded channel matches the surface of the tube segment of the pre-embedded channel (generally an arc surface). The two reaction fixing supports 2 have a gap distance from the shear test point. The two force transmission rods 3 are parallel to the connecting rod 8 and symmetrically arranged on both sides of the connecting rod 8. One end of the two force transmission rods 3 is fixedly connected to the reaction beam 1 and the other end abuts against the pre-embedded channel 100. The displacement sensor 7 is used to measure the distance the transverse shear test point moves in the transverse shear direction. The movement of the shear test point is synchronous with the movement of the sleeve 6 and the force transmission box 5. Therefore, the measurement of the movement distance of the shear test point can be converted into the measurement of the movement distance of the force transmission box 5. In this embodiment, the probe of the displacement sensor 7 is pressed against the force transmission box 5 to measure the movement distance of the force transmission box 5.

[0027] It also includes a polytetrafluoroethylene (PTFE) gasket 10, which is placed between the force transmission box 5 and the pre-embedded channel 100 to reduce friction between the force transmission box 5 and the concrete surface of the assembly, thereby improving testing accuracy. The PTFE gasket and the side of the force transmission box that mates with the pre-embedded channel conform to the surface of the pre-embedded channel segment (generally an arc-shaped surface). The sleeve is cylindrical, and the force transmission box has a cylindrical hole that fits the sleeve body. The sleeve is placed in the cylindrical hole. Making the sleeve cylindrical can reduce stress concentration between the force transmission box and the sleeve during force transmission.

[0028] Each of the two reaction force fixing supports 2 is provided with a blind hole, and the other end of the two force transmission rods 3 is placed in the two blind holes and abuts against the blind end of the blind hole.

[0029] Each reaction force fixed support 2 is fixedly connected to the pre-embedded channel 100 by a number of second bolts 201 and second nuts 202 evenly spaced along the pre-embedded channel 100, forming multiple fixed points to distribute the load distribution between the reaction force fixed support 2 and the pre-embedded channel 100. Usually, the number of fixed points on the two reaction force fixed supports 2 is equal, and the interval between the fixed points on each reaction force fixed support 2 is equal.

[0030] In this embodiment, the force sensor 4 is an S-type force sensor. The first bolt 101 is a T-type bolt. The second bolt 201 is a T-type bolt.

[0031] An in-situ self-reactive force testing method for transverse shear of pre-embedded channels, employing the aforementioned in-situ self-reactive force testing device; includes the following operating steps:

[0032] First, the force application mechanism 9 is used to pre-tighten the entire in-situ testing device to ensure close contact between all components of the in-situ testing device and eliminate the virtual displacement between the components. This virtual displacement includes the gap displacement between the force transmission rod 3 and the reaction force fixed support 2. Specifically, the force application mechanism 9 drives the connecting rod 8 to move down, while the reaction force beam 1 moves up relative to the connecting rod 8 and presses against the reaction force fixed supports 2 on both sides.

[0033] Then, the force-applying mechanism 9 pulls the connecting rod 8 downward relative to the reaction beam 1, while the reaction beam 1 moves upward relative to the connecting rod 8 and lifts the reaction fixing supports 2 on both sides, causing the shear test point of the pre-embedded channel 100 to move downward (the force exerted by the connecting rod on the shear test point of the pre-embedded channel 100 is transmitted through the force transmission box, sleeve, and first bolt). After the displacement sensor 7 detects that the shear test point has moved down to the set distance, the force-applying mechanism maintains the current force applied to the connecting rod constant. In order to overcome its own deformation, the pre-embedded channel 100 generates a self-reaction force on this in-situ testing device. When the self-reaction force is generated, please refer to... Figure 2The force on the reaction beam 1 is equal to and opposite in direction to the force on the two reaction fixed supports 2. The connecting rod 8 and the force sensor 4 are subjected to tensile stress. The magnitude of the tensile force formed by this tensile stress reflects the transverse shear bearing capacity of the embedded channel 100. Therefore, the magnitude of this self-reaction force can be measured by the force sensor 4. The "up" and "down" in "upward movement" and "downward movement" only indicate a pair of opposite directions.

[0034] In a preferred embodiment, the force-applying mechanism 9 includes a rotary wrench 92 and a force-applying nut 91. The other end of the connecting rod 8 is threaded externally. The force-applying nut 91 is screwed to the other end of the connecting rod 8, limiting the reaction beam 1 between the force-applying mechanism 9 and the pre-embedded channel 100. The rotary wrench is adapted to the force-applying nut 91. When force is applied, the force-applying nut 91 is rotated by the rotary wrench, causing it to rotate relative to the connecting rod 8 and drive the reaction beam 1 to move upwards along the connecting rod 8 relative to it. The connecting rod 8 then moves downwards relative to the reaction beam 1. In this embodiment, the rotational torque of the rotary wrench 92 is converted into an upward pushing force on the reaction beam 1 against the two reaction beam fixed supports.

[0035] In another preferred embodiment, the force-applying mechanism is a through-hole hydraulic jack, which is connected to the other end of the connecting rod 8 and abuts against the reaction beam 1. When force is applied, the through-hole hydraulic jack pulls the connecting rod 8 downward, causing the connecting rod 8 to move downward relative to the reaction beam 1. At the same time, the connecting rod 8 pulls the shear force test point of the pre-embedded channel 100 downward, while the two sides of the shear force test point of the pre-embedded channel 100 move upward relative to the ground.

[0036] The above description is merely a preferred embodiment of the present invention, and therefore should not be construed as limiting the scope of the present invention. All equivalent changes and modifications made in accordance with the scope of the patent and the contents of the specification should still fall within the scope of the present invention.

Claims

1. An in-situ self-reaction force testing device for transverse shear of pre-embedded channels, characterized in that: The system includes a self-reaction module, a force-applying module, and a data acquisition module. The self-reaction module comprises a reaction beam, two reaction support brackets, and two force transmission rods. The force-applying module includes a force transmission box, a sleeve, a connecting rod, and a force-applying mechanism. The data acquisition module includes a force sensor and a displacement sensor. The sleeve's central hole is aligned with the shear test point, and the sleeve's central axis is perpendicular to the pre-embedded channel. The sleeve and the pre-embedded channel are fixedly connected by a first bolt and a first nut placed at the shear test point. The force transmission box is fitted around the sleeve. The two tension ends of the force sensor are respectively connected to the force transmission box and one end of the connecting rod. The other end of the connecting rod passes through the reaction beam and is slidably connected to it. The other end of the connecting rod is connected to the force-applying mechanism, which limits the reaction beam between the force-applying mechanism and the pre-embedded channel. The device can drive the connecting rod to move relative to the reaction beam, causing the connecting rod to move away from the shear test point. The line connecting the connecting rod, the two tension ends of the force sensor, and the shear test point is a straight line, and this straight line is perpendicular to the central axis of the sleeve and the pre-embedded channel. The two reaction force fixed supports are symmetrically arranged on both sides of the shear test point and fixedly connected to the pre-embedded channel. The two force transmission rods are parallel to the connecting rod and symmetrically arranged on both sides of the connecting rod. One end of the two force transmission rods is fixedly connected to the reaction beam, and the other end abuts against the pre-embedded channel. The displacement sensor is used to measure the distance the shear test point moves in the transverse shear direction. The sleeve is cylindrical, and the force transmission box has a column hole adapted to the sleeve body. The sleeve is placed in the column hole. The movement of the shear test point is synchronous with the movement of the sleeve and the force transmission box.

2. The in-situ self-reaction force testing device for transverse shear of a pre-embedded channel according to claim 1, characterized in that: It also includes a polytetrafluoroethylene gasket, which is placed between the force transmission box and the pre-embedded channel.

3. The in-situ self-reaction force testing device for transverse shear of a pre-embedded channel according to claim 1, characterized in that: Each of the two reaction force fixing supports is provided with a blind hole, and the other end of the two force transmission rods is placed in the two blind holes and abuts against the blind end of the blind hole.

4. The in-situ self-reaction force testing device for transverse shear of a pre-embedded channel according to claim 1, characterized in that: Each reaction force fixed support is fixedly connected to the pre-embedded channel by a number of second bolts and second nuts evenly spaced along the pre-embedded channel.

5. The in-situ self-reaction force testing device for transverse shear of a pre-embedded channel according to claim 1, characterized in that: This force sensor is an S-type force sensor.

6. The in-situ self-reaction force testing device for transverse shear of a pre-embedded channel according to claim 1, characterized in that: The first bolt is a T-bolt.

7. The in-situ self-reaction force testing device for transverse shear of a pre-embedded channel according to claim 4, characterized in that: The second bolt is a T-bolt.

8. The in-situ self-reaction force testing device for transverse shear of a pre-embedded channel according to claim 1, characterized in that: The force-applying mechanism includes a rotary wrench and a force-applying nut. The other end of the connecting rod is threaded externally. The force-applying nut is screwed to the other end of the connecting rod and limits the reaction beam between the force-applying mechanism and the pre-embedded channel. The rotary wrench is adapted to the force-applying nut.

9. The in-situ self-reaction force testing device for transverse shear of a pre-embedded channel according to claim 1, characterized in that: The force-applying mechanism is a through-hole hydraulic jack, which is connected to the other end of the connecting rod and abuts against the reaction beam.

10. A method for testing the in-situ self-reaction force of transverse shear in a pre-embedded channel, characterized in that: The in-situ self-reactive force testing device as described in any one of claims 1 to 9 is used. First, the entire in-situ self-reactive force testing device is pre-tightened by the force application mechanism to ensure close contact between all components and eliminate any virtual displacement. Then, the connecting rod is pulled relative to the reaction beam by the force application mechanism, which moves the shear test point of the pre-embedded channel. When the displacement sensor detects that the shear test point has moved to a set distance, the force application mechanism maintains the current force applied to the connecting rod constant and reads the force value measured by the force sensor, which is the transverse shear bearing capacity of the pre-embedded channel.

Images