A prestressed steel cable tension test device

Abstract

The present invention discloses a prestressed steel cable tension testing device. The prestressed steel cable tension testing device comprises: a detection box, a central support block is installed above the detection box, tripods are installed on both sides of the detection box, distal support blocks are installed on the tripods, an adjusting tube is installed at the bottom of the detection box, a touch screen is installed on one side of the detection box, and a detection mechanism is installed in the detection box; the detection mechanism comprises a lifting plate installed in the detection box, and the top of the lifting plate is connected to the central support block. The prestressed steel cable tension testing device provided by the present invention is provided with a detection box, a central support block, a distal support block, an adjusting tube, a touch screen and a detection mechanism, and uses the adjusting tube to drive the central support block to rise, so as to lift the middle part of the steel cable to a certain height, thereby being able to conveniently display the axial force and lateral tension of the steel cable, and is more convenient and quick to use.

Description

Technical Field

[0001] The invention relates to the technical field of steel cable testing devices, and in particular to a prestressed steel cable tension testing device. Background Art

[0002] With the extensive application of prestressed technology in engineering practice and the deepening of its understanding, against the backdrop of frequent diseases and accidents of prestressed concrete bridges, the engineering community has re-examined the basic theories including prestressed design methods, prestressed application technology, and prestressed loss and time-varying effects involving prestressed bridge systems, and even had doubts about local areas. Therefore, the related research work that has occurred concurrently has also received more and more attention from scholars at home and abroad.

[0003] The function of use is reduced, and it is in a "sick" or even "dangerous" state. Its technical status is not optimistic. Due to the influence of construction factors, material properties and environmental conditions, the prestress in the steel bars of the in-service prestressed concrete structure decreases with the tensioning, anchoring process and the passage of time. This phenomenon is called prestress loss. The prestress value of the steel bars required in the design should be the actual remaining prestress in the steel bars after deducting the stress loss in the corresponding stage. Because the structure has been used for many years, under the influence of the natural environment, the use environment and the internal factors of the materials, the structural performance is changing. In addition, factors such as the non-straight pipeline, the failure of the positioning bar, the rust of the prestressed bar, the long-term shrinkage of the concrete, and the inaccurate creep estimation will lead to differences between the effective prestress of the prestressed bars and the theoretical value, thereby affecting the performance and life of the bridge structure. In severe cases, it will also lead to structural safety accidents.

[0004] Therefore, it is necessary to provide a prestressed steel cable tension testing device to solve the above technical problems. Summary of the invention

[0005] In view of the above situation, in order to overcome the defects of the prior art, the present invention provides a prestressed steel cable tension testing device which can display the axial force and lateral tension of the steel cable and is more convenient and quick to use.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0007] The prestressed steel cable tension testing device comprises: a detection box, a central support block is installed above the detection box, tripods are installed on both sides of the detection box, a distal support block is installed on the tripod, a detection mechanism is installed inside the detection box, the detection mechanism is connected to a touch screen installed on one side of the detection box, an adjustment tube is installed at the bottom of the detection box, and the adjustment tube is used to adjust the height of the central support block; the detection mechanism comprises a lifting plate installed in the detection box, the top of the lifting plate is connected to the central support block, a displacement sensor and a pressure sensor are installed in the detection box, the displacement sensor and the pressure sensor are connected to a control board, the control board is connected to the touch screen, a scale is installed on the side of the lifting plate facing the displacement sensor, the displacement sensor indirectly detects the displacement of the lifting plate by detecting the displacement of the scale, an elastic part is installed on one side of the lifting plate, a screw is installed at the bottom of the lifting plate, and the screw is threadedly connected to the adjustment tube.

[0008] Preferably, an alarm is installed on the detection box.

[0009] Preferably, a threaded tube is installed on the adjusting tube, and a force adding rod is threadedly installed on one end of the threaded tube.

[0010] Preferably, the bottom end of the central support block is fixedly mounted on the top end of the lifting plate through two vertical plates, and a first arc-shaped slot is formed on the top of the central support block.

[0011] Preferably, L-shaped clamps are rotatably installed on both sides of the central support block, and clamping grooves are provided on the clamps. A countersunk hole is opened on the central support block, and a support block is installed in the countersunk hole. A plug-in column is installed at the bottom end of the support block, and the plug-in column passes through the countersunk hole. A connecting rod is installed at the bottom end of the plug-in column, and a linkage rod is installed between the end of the connecting rod and the bottom end of the clamp.

[0012] Preferably, a return spring is sleeved on the plug-in column.

[0013] Preferably, a second slot is provided on the top of the support block.

[0014] Preferably, a snap-in groove is provided on the distal support block.

[0015] Preferably, a quadrangular prism-shaped clamp is installed at one end of the tripod, a mounting groove adapted to the clamp is opened at the bottom of the distal support block, and limiting holes are opened on the clamp and the distal support block, and the mounting pin is inserted into the limiting hole.

[0016] Preferably, a positioning column and an orientation bar are installed in the installation groove, and a positioning hole and an orientation groove are provided on the clamping head.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] (1) The present invention is provided with a detection box, a central support block, a distal support block, an adjustment tube, a touch display screen and a detection mechanism, and uses the adjustment tube to drive the central support block to rise, so as to lift the middle part of the steel cable to a certain height, thereby conveniently displaying the axial force and lateral tension of the steel cable, which is more convenient and quick to use;

[0019] (2) The present invention can utilize the pressure of the steel cable to drive the clamping claw to rotate and fix the steel cable in the first slot by arranging the clamping claw, the supporting block, the linkage rod, the plug-in column and the connecting rod;

[0020] (3) The present invention can reduce the damage of the central support block to the steel cable by providing an arc-shaped first groove on the top of the central support block;

[0021] (4) The present invention can facilitate the lifting and resetting of the support block and the automatic opening of the clamping claw by installing a reset spring on the plug-in column;

[0022] (5) The present invention can improve the stability of the steel cable on the top of the support plate by providing a second slot on the top of the support block;

[0023] (6) The present invention can conveniently replace the distal support block by providing a clamping head, a mounting groove, a limiting hole and a pin rod, so as to adapt to the use of steel cables of different specifications;

[0024] (7) The present invention can facilitate the correct installation of the distal support block by providing positioning holes, positioning columns, orientation grooves and orientation strips. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of the structure of a prestressed steel cable tension testing device provided by the present invention;

[0026] Figure 2 for Figure 1 The schematic diagram of the use of the prestressed steel cable tension test device shown;

[0027] Figure 3 for Figure 1 The structural schematic diagram of the detection mechanism in the prestressed steel cable tension test device shown;

[0028] Figure 4 for Figure 1 The structural schematic diagram of the central support block in the prestressed steel cable tension test device shown;

[0029] Figure 5 for Figure 1 A schematic cross-sectional view of the central support block in the prestressed steel cable tension test device shown;

[0030] Figure 6 for Figure 1A schematic diagram of the connection structure between a tripod and a distal support block in a prestressed steel cable tension test device shown;

[0031] Figure 7 for Figure 1 A schematic diagram of the structure of the distal support block in the prestressed steel cable tension test device shown;

[0032] Figure 8 for Figure 1 A schematic diagram of the connection of the support block, the plug-in column and the connecting rod in the prestressed steel cable tension test device shown;

[0033] Fig. 9 This is a schematic diagram of the force analysis of the steel cable tension test device during testing.

[0034] Among them, the names corresponding to the figure marks are: 1-test box, 2-center support block, 3-tripod, 4-distal support block, 5-adjusting tube, 6-touch display screen, 7-lifting plate, 8-displacement sensor, 9-pressure sensor, 10-elastic part, 11-scale, 12-screw, 13-threaded tube, 14-force rod, 15-first slot, 16-clamp, 17-countersunk hole, 18-support block, 19-linkage rod, 20-reset spring, 21-clamp slot, 22-clamping slot, 23-clamp head, 24-installation slot, 25-limiting hole, 26-pin rod, 27-positioning hole, 28-positioning column, 29-directional slot, 30-directional strip, 31-second slot, 32-plug column, 33-connecting rod. DETAILED DESCRIPTION

[0035] The present invention is further described below in conjunction with the accompanying drawings and embodiments. The embodiments of the present invention include but are not limited to the following embodiments.

[0036] Embodiment 1:

[0037] like Figure 1-9As shown, the prestressed steel cable tension test device provided by the present invention comprises: a test box 1, a central support block 2 is installed above the test box 1, tripods 3 are installed on both sides of the test box 1, and a distal support block 4 is installed on the tripod 3. A detection mechanism is installed inside the test box 1, and the detection mechanism is connected to a touch display screen 6 installed on one side of the test box 1. An adjustment tube 5 is installed at the bottom of the test box 1, and the adjustment tube 5 is used to adjust the height of the central support block 2. In this embodiment, the detection mechanism comprises a lifting plate 7 installed in the test box 1, and the top of the lifting plate 7 is connected to the central support block 2. Then, a displacement sensor 8 and a pressure sensor 9 are installed in the detection box 1, and the displacement sensor 8 and the pressure sensor 9 are connected to the control board, and the control board is connected to the touch display screen 6. A scale 11 is installed on the side of the lifting plate 7 facing the displacement sensor 8. The displacement sensor 8 detects the displacement of the scale 11, thereby indirectly detecting the displacement of the lifting plate 7. An elastic member 10 is installed on one side of the lifting plate 7. The elastic member 10 can be a spring or other parts with similar functions. A screw 12 is installed at the bottom of the lifting plate 7. The screw 12 is threadedly connected to the adjusting tube 5. When in use, Figure 2 As shown, the two distal support blocks 4 and the central support block 3 are connected to the steel cable, and the adjusting tube 5 is rotated to raise the screw rod 12, and the raising of the screw rod 12 drives the lifting plate 7 to rise, thereby raising the central support block 2, and lifting the middle part of the steel cable to a certain height (the lateral displacement δ of the steel cable from the initial state). At the same time, the displacement sensor 8 detects the displacement length of the lifting plate 7, that is, the δ value, and the elastic member 10 presses the pressure sensor 9, and the pressure sensor 9 detects the pressure value T. The distance between the two distal support blocks 4 is L, according to the following formula:

[0038] T=2Fsinθ (1)

[0039] 0=sin0=tan0=2δ / L (2)

[0040] Substituting (2) into (1) we get:

[0041]

[0042] Formula (3) is the basic theoretical formula for determining the effective prestress of prestressed steel strands using the static transverse tension method.

[0043] The displacement sensor 8 and the pressure sensor 9 transmit data to the controller, which calculates and analyzes the data. The data analysis and calculation method is a combination of the step difference method and the least squares method.

[0044] When the existing prestressed steel beam tester conducts the target steel beam transverse tension test, it is difficult to ensure the consistency of the initial state of each measurement, resulting in the absolute error of the instrument and the measurement error caused by the instrument's own weight accounting for a large proportion of the entire system error. The step difference method can eliminate the influence of the test error. The step difference method is based on the incremental relationship between the original data. It uses the transverse tension values ​​corresponding to different levels of transverse displacement and the incremental difference between the initial transverse displacement and transverse tension to eliminate the influence of the test error using the mathematical step difference method. The specific formula is as follows:

[0045] ΔT=T i+1 -T i , Δδ=δ i+1 -δ i

[0046] (i=1,2……) (4)

[0047] When it is known that the lateral displacement of the tendon increases from δ1 to δ2, the corresponding lateral tension force increases from T1 to T2. Then, combined with formula (4), the difference between the two-level increments can be obtained:

[0048]

[0049] Thus, the effective tensile force calculation formula practical in engineering is obtained:

[0050]

[0051] During multiple repetitive tests, the average effective prestressing value of the steel strand is calculated using formula (6).

[0052]

[0053] Where: F i ——The effective tension value of the prestressed steel tendon at the measuring point for the i-th time, kN;

[0054] n——the number of independent repeated tests;

[0055] F i ——Average value of effective prestressing of steel tendons.

[0056] Finally, the target steel tendon effective stress tension value is solved.

[0057] After the controller calculates the effective stress tension value of the steel cable, the controller transmits the data to the touch screen 6, and the data is displayed on the touch screen 6, so that the user can view the data conveniently. It is worth noting that the display data of the touch screen 6 includes the transverse tension T, the transverse displacement δ, the axial force F of the prestressed steel strand, and the effective length L.

[0058] By setting up a detection box 1, a central support block 2, a distal support block 4, an adjusting tube 5, a touch display screen 6 and a detection mechanism, the adjusting tube 5 is used to drive the central support block 2 to rise, and the middle part of the steel cable is lifted to a certain height, so that the axial force and lateral tension of the steel strand of the steel cable can be easily calculated, and the use is more convenient and quick.

[0059] Embodiment 2:

[0060] An alarm is installed on the detection box 1, and the alarm is connected to the controller. When it is detected that the axial force F of the steel cable reaches the threshold value, the touch screen displays a warning sign and the alarm sounds an alarm to remind the operator to pay attention to safety.

[0061] By installing an alarm on the detection box 1, the operator can be reminded when the axial force of the steel cable reaches a threshold value, thereby improving the safety of the device.

[0062] Embodiment 3:

[0063] like Figure 3 As shown, a threaded tube 13 is installed on the adjusting tube 5, and a force rod 14 is threadedly installed on one end of the threaded tube 13. When in use, one end of the force rod 14 is screwed into the threaded tube 13, and then the tail end of the force rod 14 is held, so that the adjusting tube 5 can be rotated conveniently and labor-savingly.

[0064] By installing the threaded tube 13 and the force rod 14 on the threaded tube 5 , the adjusting tube 5 can be rotated conveniently and labor-savingly, and the assembly and disassembly of the force rod 14 are convenient.

[0065] Embodiment 4:

[0066] like Figure 4-5 As shown, the bottom end of the central support block 2 is fixedly mounted on the top of the lifting plate 7 through two vertical plates. A first arc-shaped slot 15 is provided on the top of the central support block 2. When in use, the steel cable is embedded in the first slot 15. When the steel cable is lifted up, the middle part of the arc-shaped slot 15 is raised. The first arc-shaped slot 15 has no edges and corners, so when it contacts the steel cable, it causes less damage to the steel cable.

[0067] By providing an arc-shaped first clamping groove 15 on the top of the central support block 2, the damage of the central support block 2 to the steel cable can be reduced.

[0068] Embodiment 5:

[0069] like Figure 4-5 and Figure 8As shown, L-shaped clamping jaws 16 are rotatably installed on both sides of the central support block 2, and clamping grooves 31 are provided on the clamping jaws 16. In one case, the clamping jaws 16 can be driven to rotate by installing bolts at the lower end. In another case, a countersunk hole 17 can be opened on the central support block 2, and a support block 18 is installed in the countersunk hole 17. A plug-in column 32 is installed at the bottom end of the support block 18, and the plug-in column 32 passes through the countersunk hole 17. A connecting rod 33 is installed at the bottom end of the plug-in column 32, and the end of the connecting rod 33 is connected to the A linkage rod 19 is installed between the bottom ends of the clamping jaws 16. When in use, the steel cable is pressed on the top of the support block 18. When the central support block 2 is raised, the support block 18 is lowered, and then the clamping jaws 16 on both sides of the central support block 2 are flipped through the plug-in column 32, the connecting rod 33 and the linkage rod 19, so that the top of the clamping jaws 16 rotate toward the direction close to the top of the central support block 2, thereby pressing down and holding the steel cable, and the clamping groove 21 is stuck on the upper side of the steel cable, so that the steel cable can be more stably fixed in the first clamping groove 15.

[0070] By providing the clamping jaw 16 , the support block 18 , the linkage rod 19 , the plug-in column 32 and the connecting rod 33 , the pressure of the steel cable can be utilized to drive the clamping jaw 16 to rotate, and the steel cable can be fixedly pressed into the first clamping groove 15 .

[0071] Embodiment 6:

[0072] like Figure 4 As shown, a return spring 20 is sleeved on the plug-in column 32. When in use, when the support block 18 is pressed down, the return spring 20 contracts. After the device is removed from the steel cable, the return spring 20 recovers, driving the support block 18 to rise and reset, thereby opening the clamping jaws 16.

[0073] By sleeve-mounting the reset spring 20 on the plug-in column 32 , the support block 18 can be lifted and reset and the clamping jaw 16 can be opened automatically.

[0074] Embodiment 7:

[0075] like Figure 8 As shown, a second slot 31 is provided at the top of the support block 18, and the steel cable can be embedded in the second slot 31. When in use, the bottom of the steel cable is stuck in the second slot 31, making it difficult to move, and further making it difficult to slide off from the top of the support plate 18 to both sides.

[0076] By providing the second slot 31 on the top of the support block 18 , the stability of the steel cable on the top of the support plate 18 can be improved.

[0077] Embodiment 8:

[0078] like Figure 6 As shown, a clamping groove 22 is provided on the distal support block 4, and the steel cable is clamped into the clamping groove 22 from the side, so that the distal support block 4 can be hung on the steel cable, thereby conveniently connecting the distal support block 4 with the steel cable.

[0079] By providing a clamping groove 22 with a side opening on the distal support block 4, the distal support block 4 can be conveniently connected to the steel cable.

[0080] Embodiment 9:

[0081] like Figure 6-7 As shown, a quadrangular prism-shaped clamping head 23 is installed at one end of the tripod 3, and a mounting groove 24 adapted to the clamping head 23 is opened at the bottom of the distal support block 4. Limiting holes 25 are opened on the clamping head 23 and the distal support block 4, and a mounting pin 26 is inserted into the limiting hole 25. When in use, the mounting groove 24 at the bottom of the distal support block 4 is sleeved on the clamping head 23, so that the inner wall of the mounting groove 24 is completely in contact with each surface of the clamping head 23, so that the position of the distal support block 4 is accurate. At this time, the limiting holes 25 are aligned, and the pin 26 is inserted into the limiting hole 25, thereby connecting the distal support block 4 to the tripod 3. At the same time, the distal support block 4 can be easily replaced to adapt to the use of steel cables of different specifications.

[0082] By providing the clamping head 23, the mounting groove 24, the limiting hole 25 and the pin rod 26, the distal support block 4 can be conveniently replaced so as to be adapted to the use of steel cables of different specifications.

[0083] Embodiment 10:

[0084] like Figure 6-7 As shown, in this embodiment, a positioning column 28 and an orientation bar 30 are installed in the installation groove 24, and a positioning hole 27 and an orientation groove 29 are provided on the clamping head 23. During assembly, the orientation bar 30 is installed in the direction of the orientation groove 29, the positioning column 28 is inserted into the positioning hole 27, and the orientation bar 30 is inserted into the orientation groove 29, thereby facilitating the installation of the distal support block 4 and preventing it from being installed in the wrong direction.

[0085] By providing the positioning hole 27 , the positioning column 28 , the orientation slot 29 and the orientation strip 30 , the correct installation of the distal support block 4 can be facilitated.

[0086] Working principle: When in use, the two distal support blocks 4 and the central support block 3 are connected to the steel cable, and the adjusting tube 5 is rotated to raise the screw rod 12. The raising of the screw rod 12 drives the lifting plate 7 to rise, and then the central support block 2 is raised, and the middle part of the steel cable is lifted to a certain height. At the same time, the displacement sensor 8 detects the displacement length of the lifting plate 7, and the elastic member 10 presses the pressure sensor 9. The pressure sensor 9 detects the pressure value. Through calculation, the effective stress tension value of the steel cable is obtained, and the controller transmits the data to the touch display screen 6. The data is displayed on the touch display screen 6, which is convenient for users to view the data.

Claims

1. A prestressed steel cable tension test device, characterized in that: include: A detection box (1), wherein a central support block (2) is installed above the detection box (1), tripods (3) are installed on both sides of the detection box (1), a distal support block (4) is installed on the tripod (3), an adjustment tube (5) is installed at the bottom of the detection box (1), a touch display screen (6) is installed on one side of the detection box (1), and a detection mechanism is installed in the detection box (1); The detection mechanism comprises a lifting plate (7) installed in the detection box (1), the top of the lifting plate (7) is connected to the central support block (2), a displacement sensor (8) and a pressure sensor (9) are installed in the detection box (1), the displacement sensor (8) and the pressure sensor (9) are connected to the touch display screen (6), a scale (11) is installed on one side of the lifting plate (7), an elastic member (10) is installed on one side of the lifting plate (7), a screw rod (12) is installed at the bottom of the lifting plate (7), and the screw rod (12) is connected to the adjustment tube (5).

2. A prestressed steel cable tension testing device according to claim 1, characterized in that: An alarm is installed on the detection box (1).

3. A prestressed steel cable tension test device according to claim 1, characterized in that: A threaded tube (13) is installed on the adjusting tube (5), and a force rod (14) is installed on one end of the threaded tube (13).

4. A prestressed steel cable tension test device according to claim 1, characterized in that: The top of the central support block (2) is provided with an arc-shaped first clamping groove (15).

5. A prestressed steel cable tension testing device according to claim 1, characterized in that: L-shaped clamping claws (16) are rotatably mounted on both sides of the central support block (2), and the clamping claws (16) are provided with clamping grooves (21). A countersunk hole (17) is provided on the central support block (2), and a support block (18) is installed in the countersunk hole (17). A plug-in column (32) is installed at the bottom end of the support block (18), and the plug-in column (32) passes through the countersunk hole (17). A connecting rod (33) is installed at the bottom end of the plug-in column (32), and a linkage rod (19) is installed between the end of the connecting rod (33) and the bottom end of the clamping claw (16).

6. A prestressed steel cable tension testing device according to claim 5, characterized in that: A return spring (20) is sleeved on the plug-in column (32).

7. A prestressed steel cable tension testing device according to claim 5, characterized in that: A second slot (31) is provided on the top of the support block (18).

8. A prestressed steel cable tension testing device according to claim 1, characterized in that: The distal support block (4) is provided with a clamping groove (22).

9. A prestressed steel cable tension test device according to claim 1, characterized in that: A quadrangular prism-shaped clamping head (23) is installed at one end of the tripod (3); a mounting groove (24) is provided at the bottom of the distal support block (4); a limiting hole (25) is provided on the clamping head (23) and the distal support block (4); and a mounting pin rod (26) is inserted into the limiting hole (25).

10. A prestressed steel cable tension testing device according to claim 9, characterized in that: A positioning column (28) and an orientation bar (30) are installed in the installation groove (24), and a positioning hole (27) and an orientation groove (29) are provided on the clamping head (23).

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