A prestressed steel bar impact protection test device and test method

Abstract

The present invention provides a prestressed steel bar impact protection test device and a test method, including: a positioning mechanism, a fixing mechanism is installed on the positioning mechanism, both the positioning mechanism and the fixing mechanism are connected to a steel bar assembly, and the fixing mechanism is connected to a test mechanism; the fixing mechanism includes a fixing shell, the side end of the fixing shell contacts a threaded block, through holes are provided through the upper and lower ends of the fixing shell, the fixing shell is fixedly connected to a force-applying block, a through hole is provided through one end of the fixing shell away from the force-applying block, and the through hole is communicated with the through hole; by applying a load to the force-applying block to simulate an impact load, the load can be transmitted to the steel bar through the fixing shell, solving the technical problem that at present, prestressed steel bar impact protection tests usually adopt steel bar pull-out tests, and most of the steel bar pull-outs are static loading. In actual situations, steel bars will bear impact loads, and there is very little research on steel bar pull-out tests under impact loads.

Description

Technical Field

[0001] The present invention relates to the technical field of impact protection tests, and particularly relates to a prestressed steel bar impact protection test device and a test method. Background Art

[0002] Threaded steel bars for prestressed concrete, also known as precision rolled threaded steel bars, are widely used in prestressed concrete bridge structures, such as the cable tower anchorage area of cable-stayed bridges, concrete box girders and other parts. In order to make the concrete structure meet the design crack resistance requirements, it is necessary to pre-apply a high level of elastic potential energy to the precision rolled threaded steel bars during construction. Since its material is low-alloy steel with strong brittleness and is prone to delayed fracture, it is necessary to conduct tests on the fracture phenomenon and preventive measures of prestressed steel bars.

[0003] At present, prestressed steel bar impact protection tests usually adopt steel bar pull-out tests. Most of the steel bar pull-outs are static loading. In actual situations, steel bars will bear impact loads, and there is very little research on steel bar pull-out tests under impact loads. Summary of the Invention

[0004] The present invention provides a prestressed steel bar impact protection test device and a test method, which are used to solve the above technical problems that prestressed steel bar impact protection tests usually adopt steel bar pull-out tests, most of the steel bar pull-outs are static loading, in actual situations, steel bars will bear impact loads, and there is very little research on steel bar pull-out tests under impact loads.

[0005] To solve the above technical problems, the present invention discloses a prestressed steel bar impact protection test device, including: a positioning mechanism, a fixing mechanism is installed on the positioning mechanism, both the positioning mechanism and the fixing mechanism are connected to a steel bar assembly, and the fixing mechanism is connected to a test mechanism.

[0006] Preferably, the steel bar assembly includes concrete, a steel bar is cast in the concrete, and a threaded block is threadedly connected to the threaded end of the steel bar.

[0007] Preferably, the fixing mechanism includes a fixing shell, the side end of the fixing shell contacts the threaded block, fixing cavities are provided through the upper and lower ends of the fixing shell, the fixing shell is fixedly connected to a force-applying block, a through hole is provided through one end of the fixing shell away from the force-applying block, and the through hole is communicated with the fixing cavity.

[0008] Preferably, the positioning mechanism includes a base, the concrete is placed on the base, a plurality of guiding and positioning plates are evenly arranged at intervals on the upper end of the base, guiding cavities are provided through the left and right ends of the guiding and positioning plates, and the guiding cavities are slidably connected to the fixing shell.

[0009] Preferably, the positioning mechanism further includes a positioning plate, the positioning plate is fixedly installed on the upper left side of the base, a positioning groove is provided on the upper end of the positioning plate, the positioning plate contacts the concrete, and the steel bar passes through the positioning groove and the through hole in sequence and is communicated with the outside.

[0010] Preferably, a damper is fixedly installed on the right side of the upper end of the base. A buffer block is provided at one end of the steel bar close to the damper, and the buffer block is arranged corresponding to the damper. Strain gauges I are connected to both the steel bar and the force application block, and the strain gauges I on the steel bar and the force application block are connected in series.

[0011] Preferably, a quick-release mechanism is fixedly provided in the through hole. The quick-release mechanism includes a fixed sleeve I, which is rotatably arranged in the through hole. Installation holes I are provided through the left and right ends of the fixed sleeve I, and a plurality of clamping components are circumferentially and evenly arranged in the installation holes I for clamping the steel bar. The fixed sleeve I is rotatably connected to a fixed sleeve II. Installation holes II are provided through the left and right ends of the fixed sleeve II, and the installation holes II communicate with the installation holes I, and the installation holes I cooperate with the steel bar.

[0012] Preferably, the fixed sleeve I is connected with a driving component, and the driving component is connected with a positioning component for limiting the extrusion component. The extrusion component includes two rotating rods, which are rotatably arranged in the moving groove and are in contact with the airbag in the moving groove. The moving grooves are symmetrically arranged on the upper and lower sides of one end of the fixed sleeve II away from the fixed sleeve I. The airbag is connected to the air rod through a communication pipeline, and the air rod is fixedly connected to the extrusion plate. The extrusion plate is slidably arranged in the sliding groove I, and the sliding groove I is symmetrically arranged on the upper and lower sides of the installation hole II. The extrusion plate extrudes and fixes the steel bar.

[0013] Preferably, it further includes a multi-directional test mechanism. The multi-directional test mechanism includes a base, and a connection groove and a test groove are fixedly provided at the upper end of the base. Concrete is fixedly connected in the connection groove. The test groove is slidably connected to a sliding block I, and the sliding block I is fixedly connected to a hydraulic cylinder. The hydraulic cylinder is fixedly installed on the base. The sliding block I is provided with a fixing hole, and the fixing hole is fixedly connected to the steel bar. A sliding groove II is provided on the sliding block I, and the sliding groove II is slidably connected to a sliding block II. An adjusting rod is fixedly connected to the sliding block II, and the adjusting rod is fixedly connected to a pressing block. The pressing groove on the pressing block cooperates with the steel bar. The sliding block II is rotatably connected to a support rod, and the support rod is rotatably connected to the base.

[0014] A test method for a prestressed steel bar impact protection test device includes the following steps:

[0015] Step 1: First apply a load to the steel bar, then pour concrete on the steel bar under load, and cure it to the designed strength;

[0016] Step 2: Place the cured concrete on the base, and the steel bar passes through the positioning groove and the through hole and is threadedly connected to the threaded block;

[0017] Step 3: Apply a load to the force application block to conduct a breaking impact test;

[0018] Step 4: The strain gauges I on the steel bar and the force application block measure the deformation value of the steel bar.

[0019] Step 5: The impact protection test of the prestressed steel bars is reflected by the relationship between the applied load value on the force application block and the deformation value of the steel bars.

[0020] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Description of the Drawings

[0021] The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation to the present invention. In the drawings:

[0022] Figure 1 is a schematic structural diagram of the present invention;

[0023] Figure 2 is a schematic structural diagram of the quick-release mechanism of the present invention;

[0024] Figure 3 is a schematic side view structural diagram of one side of the fixed sleeve of the present invention;

[0025] Figure 4 is Figure 2 an enlarged structural diagram of area A in

[0026] Figure 5 is a schematic structural diagram of the multi-directional test mechanism of the present invention.

[0027] In the figure: 1, concrete; 2, steel bar; 3, fixed shell; 31, fixed cavity; 32, force application block; 33, strain gauge I; 4, positioning mechanism; 41, base; 42, positioning groove; 43, guiding and positioning plate; 44, guiding cavity; 45, positioning plate; 5, threaded block; 51, first fixed sleeve; 52, second fixed sleeve; 53, double-headed motor; 54, driving shaft; 55, gear ring; 56, first mounting hole; 57, gear; 58, first threaded rod; 59, threaded sleeve; 510, second mounting hole; 511, rotating rod; 512, airbag; 513, moving groove; 514, connecting pipeline; 515, sealing plate; 516, air rod; 517, second sealing cavity; 518, pressing plate; 519, first sliding groove; 520, telescopic rod; 521, first clamping block; 522, second clamping block; 523, fixed sleeve; 524, first sealing cavity; 525, second threaded rod; 526, limiting block; 527, sealing sleeve; 528, pipeline; 529, operation board; 6, damper; 7, base; 71, connecting groove; 72, test groove; 73, hydraulic cylinder; 74, first sliding block; 75, pressing groove; 76, second sliding groove; 77, pressing block; 78, fixing hole; 79, second sliding block; 710, adjusting rod; 711, support rod. Detailed Embodiments

[0028] The preferred embodiments of the present invention will be described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only for the purpose of illustrating and explaining the present invention, and are not used to limit the present invention.

[0029] In addition, in the present invention, descriptions such as "first" and "second" are only for descriptive purposes, and do not particularly refer to the meaning of order or sequence, nor are they used to limit the present invention. They are only used to distinguish components or operations described with the same technical terms, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions and technical features between various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0030] Embodiment 1

[0031] The embodiment of the present invention provides a prestressed steel bar impact protection test device, as Figure 1 shown, including: a positioning mechanism 4, a fixing mechanism is installed on the positioning mechanism 4, both the positioning mechanism 4 and the fixing mechanism are connected to the steel bar assembly, and the fixing mechanism is connected to a test mechanism;

[0032] The steel bar assembly includes concrete 1, a steel bar 2 is cast in the concrete 1, and a threaded block 5 is threadedly connected to the threaded end of the steel bar 2;

[0033] The fixing mechanism includes a fixing shell 3, the side end of the fixing shell 3 is in contact with the threaded block 5, fixing cavities 31 are provided through the upper and lower ends of the fixing shell 3, the fixing shell 3 is fixedly connected to a force-applying block 32, a through hole is provided through one end of the fixing shell 3 away from the force-applying block 32, and the through hole is communicated with the fixing cavity 31;

[0034] The positioning mechanism 4 includes a base 41, the concrete 1 is placed on the base 41, a plurality of guiding and positioning plates 43 are uniformly arranged at intervals on the upper end of the base 41, guiding cavities 44 are provided through the left and right ends of the guiding and positioning plates 43, and the guiding cavities 44 are slidably connected to the fixing shell 3;

[0035] The positioning mechanism 4 further includes a positioning plate 45, the positioning plate 45 is fixedly installed on the upper end left side of the base 41, a positioning groove 42 is provided on the upper end of the positioning plate 45, the positioning plate 45 is in contact with the concrete 1, and the steel bar 2 passes through the positioning groove 42 and the through hole in sequence and is communicated with the outside;

[0036] A damper 6 is fixedly installed on the upper right side of the base 41. One end of the steel bar 2 close to the damper 6 is provided with a buffer block, which is arranged corresponding to the damper 6. Strain gauges I 33 are connected to both the steel bar 2 and the force application block 32, and the strain gauges I 33 on the steel bar 2 and the force application block 32 are connected in series;

[0037] A test method for a prestressed steel bar impact protection test device includes the following steps:

[0038] Step 1: First, apply a load to the steel bar 2, then pour concrete 1 on the steel bar 2 with the load applied, and cure it to the designed strength;

[0039] Step 2: Place the cured concrete 1 on the base 41, and the steel bar 2 passes through the positioning groove 42 and the through hole and is threadedly connected to the threaded block 5;

[0040] Step 3: Apply a load to the force application block 32 to conduct a breaking impact test;

[0041] Step 4: The deformation value of the steel bar 2 is measured by the strain gauges I 33 on the steel bar 2 and the force application block 32;

[0042] Step 5: The prestressed steel bar impact protection test is reflected by the relationship between the load value applied on the force application block 32 and the deformation value of the steel bar 2.

[0043] The beneficial effects of the above technical solution are:

[0044] A load is applied to the force - applying block 32 to simulate an impact load. When applying the load to the force - applying block 32, the fixed shell 3 moves under the action of the load of the force - applying block 32. The guiding cavity 44 plays a guiding role in the movement of the fixed shell 3. The setting of the fixed cavity 31 can hold concretes 1 of different sizes and can also provide a certain degree of protection to prevent the splashing of the steel bars 2 after fracture. Moreover, the fixed shell 3 can pass through steel bars 2 of different diameters, which is convenient for the pull - out test of steel bars under different sizes. A buffer block is installed on the steel bar 2, which can increase the contact area between the steel bar 2 and the damper 6. The steel bar 2 is connected with a threaded block 5, so that when the fixed shell 3 moves under the action of the load of the force - applying block 32, it drives the steel bar 2 to move. When the fixed shell 3 moves, it drives the steel bar 2 to be pulled. When the steel bar 2 is pulled, it drives the concrete 1 to move. The positioning plate 45 on the base 41 limits the concrete 1, causing a relative displacement between the steel bar 2 and the concrete 1. When the steel bar 2 between the concretes 1 remains stationary, the steel bar 2 outside the concrete 1 deforms under the action of the load of the fixed shell 3. The strain gauges 33 on the steel bar 2 and the force - applying block 32 are used to measure the deformation value of the steel bar 2. The impact protection effect of the prestressed steel bar is reflected by the relationship between the load value applied to the force - applying block 32 and the deformation value of the steel bar 2. By applying a load to the force - applying block 32 to simulate an impact load, the load can be transmitted to the steel bar 2 through the fixed shell 3, solving the technical problem that the current impact protection test of prestressed steel bars usually uses the steel bar pull - out test, and most of the steel bar pull - out is static loading. In actual situations, steel bars will bear impact loads, and there is very little research on the steel bar pull - out test under impact loads.

[0045] Embodiment 2

[0046] On the basis of Embodiment 1, as Figures 2 - 4 shown, a quick - release mechanism is fixedly arranged in the through - hole. The quick - release mechanism includes a fixing sleeve 51. The fixing sleeve 51 is rotatably arranged in the through - hole. Installation holes 56 are provided through the left and right ends of the fixing sleeve 51. A plurality of clamping components are circumferentially and evenly arranged in the installation holes 56. The clamping component includes a telescopic rod 520. The telescopic rod 520 is fixedly connected with a clamping block 521. The clamping block 521 is slidably connected with an arc - shaped groove. The clamping block 521 is fixedly connected with a clamping block 522. The clamping block 522 clamps and fixes the steel bar 2. The clamping component is used to clamp the steel bar 2. The fixing sleeve 51 is rotatably connected with a fixing sleeve 52. A plurality of arc - shaped grooves are circumferentially and evenly arranged at one end of the fixing sleeve 52 close to the clamping block 521. Installation holes 510 are provided through the left and right ends of the fixing sleeve 52. The installation holes 510 communicate with the installation holes 56, and the installation holes 56 cooperate with the steel bar 2;

[0047] The fixing sleeve one 51 is connected with a driving component, the driving component is connected with a retaining component, the retaining component is used for limiting the extrusion component, the retaining component includes a fixing sleeve 523, the inner ring of the fixing sleeve 523 is slidably sleeved on the fixing sleeve two 52, and sealing cavities one 524 are symmetrically arranged at the upper and lower ends of the fixing sleeve 523. A sealing plate 515 is slidably arranged in the sealing cavity one 524. The sealing plate 515 is fixedly connected with a sealing sleeve 527. The sealing sleeve 527 penetrates through the side end of the sealing cavity one 524 and is threadedly connected with a threaded rod two 525. The threaded rod two 525 is fixedly connected with an operating plate 529. The left and right sides of the sealing cavity one 524 are symmetrically communicated with pipelines 528. The pipelines 528 are communicated with a sealing cavity two 517. A limiting block 526 is slidably arranged in the sealing cavity two 517. The limiting block 526 contacts with a rotating rod 511. The extrusion component includes two rotating rods 511. The two rotating rods 511 are rotatably arranged in a movable groove 513, and the rotating rods 511 contact with an airbag 512 in the movable groove 513. The movable grooves 513 are symmetrically arranged at the upper and lower sides of one end of the fixing sleeve two 52 away from the fixing sleeve one 51. The airbag 512 is connected with an air rod 516 through a communicating pipeline 514. The air rod 516 is fixedly connected with an extrusion plate 518. The extrusion plate 518 is slidably arranged in a sliding groove one 519. The sliding grooves one 519 are symmetrically arranged at the upper and lower sides of the mounting hole two 510. The extrusion plate 518 extrudes and fixes the steel bar.

[0048] The driving component includes a double-headed motor 53. The double-headed motor 53 is fixedly connected with the side end of a fixed cavity 31 through a fixed rod. The double-headed motor 53 is fixedly installed on the fixing sleeve two 52. The double-headed motor 53 is fixedly connected with a gear 57 through a driving shaft 54. The gear 57 meshes with the inner cavity of a gear ring 55. The gear ring 55 is fixedly connected with the fixing sleeve one 51. The inner cavity of the gear ring 55 cooperates with the fixing sleeve two 52. The end of the double-headed motor 53 away from the driving shaft 54 is fixedly connected with a threaded rod one 58. The threaded rod one 58 is threadedly connected with a threaded sleeve 59. The threaded sleeve 59 is fixedly connected with the fixing sleeve 523.

[0049] The beneficial effects of the above technical solution are:

[0050] By setting up a quick-release mechanism for installing and fixing the steel bar 2, the connection stability between the steel bar 2 and the fixed shell 3 is improved, and the wear of the thread between the steel bar 2 and the threaded block 5 is avoided, which affects the connection effect between the two and thus affects the impact protection test of the steel bar 2. When installing the steel bar 2, insert the steel bar 2 into the second mounting hole 510 and the first mounting hole 56, and then start the double-headed motor 53 to drive the drive shaft 54 and the first threaded rod 58 to rotate. The drive shaft 54 drives the gear 57 to rotate, the gear 57 drives the toothed ring 55 to rotate, the toothed ring 55 drives the first fixing sleeve 51 to rotate, and when the first fixing sleeve 51 rotates, it drives the first clamping block 521 to rotate through the telescopic rod 520. The arc-shaped groove guides the rotation of the first clamping block 521, and the first clamping block 521 drives the second clamping block 522 to move, thereby changing the diameter of the circular hole formed by several second clamping blocks 522. By changing the diameter of the circular hole, the second clamping blocks 522 clamp and fix the steel bar 2. When the first threaded rod 58 rotates, it drives the threaded sleeve 59 to move, the threaded sleeve 59 drives the fixing sleeve 523 to move, and when the fixing sleeve 523 slides, it drives the rotating rod 511 to rotate. When the rotating rod 511 rotates, it compresses the airbag 512, and when the airbag 512 is compressed, it pushes the gas to enter the air rod 516 through the connecting pipeline 514. The elongation of the air rod 516 drives the pressing plate 518 to move, and the pressing plate 518 clamps and fixes the steel bar 2. Then rotate the operating plate 529, the operating plate 529 drives the second threaded rod 525 to rotate, the second threaded rod 525 drives the sealing sleeve 527 to move, and the sealing sleeve 527 drives the sealing plate 515 to slide along the first sealing cavity 524. The air compressed by the sealing plate 515 in the first sealing cavity 524 enters the second sealing cavity 517 through the pipeline 528, and pushes the limiting block 526 in the second sealing cavity 517 to contact the rotating rod 511. When the second clamping blocks 522 clamp and fix the steel bar 2, the limiting block 526 just contacts the rotating rod 511, avoiding the rotation of the rotating rod 511 resulting in the separation of the pressing plate 518 from the steel bar 2, which affects the clamping and fixing of the steel bar 2 by the pressing plate 518. Under the combined action of the clamping component and the pressing component, the connection stability between the steel bar 2 and the fixed shell 3 can be further improved, and the structures of the clamping component and the pressing component are different. If one of the components is affected by the outside and cannot maintain the clamping and fixing effect on the steel bar 2, the other component can continue to maintain the normal clamping and fixing effect, avoiding the situation where two identical components cannot maintain the clamping and fixing effect on the steel bar 2 at the same time when affected by the outside, resulting in the failure of the quick-release mechanism;

[0051] When disassembling the steel bar 2, first rotate the operating plate 529 in the reverse direction so that the limiting block 526 no longer makes a limiting contact with the rotating rod 511, and rotate the rotating rod 511 in the reverse direction. At this time, the pressing plate 518 can move freely. Then control the double-headed motor 53 to rotate in the reverse direction. The double-headed motor 53 drives the fixing sleeve 523 and the second clamping blocks 522 to return to their original positions, and then pull out the steel bar 2 to complete the disassembly of the steel bar 2.

[0052] Embodiment 3

[0053] Based on Example 1, as Figure 5 shown, it further includes a multi-directional test mechanism. The multi-directional test mechanism includes a base 7. At the upper end of the base 7, a connection groove 71 and a test groove 72 are fixedly provided. Concrete 1 is fixedly connected in the connection groove 71. The test groove 72 is slidably connected with a first sliding block 74. The first sliding block 74 is fixedly connected with a hydraulic cylinder 73. The hydraulic cylinder 73 is fixedly installed on the base 7. The first sliding block 74 is provided with a fixing hole 78, and the fixing hole 78 is connected with a steel bar 2. The first sliding block 74 is provided with a second sliding groove 76. The second sliding groove 76 is slidably connected with a second sliding block 79. A regulating rod 710 is fixedly connected to the second sliding block 79. The regulating rod 710 is fixedly connected with a pressing block 77. A pressing groove 75 on the pressing block 77 cooperates with the steel bar 2. A support rod 711 is rotatably connected to the second sliding block 79. The support rod 711 is rotatably connected to the base 7.

[0054] The beneficial effects of the above technical solution are:

[0055] Select a multi-directional test mechanism for testing according to the usage requirements of the steel bar 2. When the steel bar 2 is used in a high-requirement environment, use the multi-directional test mechanism for testing. Connect the steel bar 2 to the first sliding block 74. The above quick-release mechanism can be set in the first sliding block 74, or it can be connected to the first sliding block 74 by means of threaded connection. The connection groove 71 fixes and positions the concrete 1. After the concrete 1 and the steel bar 2 are installed, adjust the length of the hydraulic cylinder 73 so that the pressing groove 75 fits the steel bar 2. Start the hydraulic cylinder 73. The hydraulic cylinder 73 drives the first sliding block 74 to move. The second sliding groove 76 guides the movement of the first sliding block 74. The movement of the first sliding block 74 axially pulls the steel bar 2, and at the same time, the pressing block 77 presses the steel bar 2 in the normal direction. By applying loads to the steel bar 2 axially and normally, a second strain gauge is set on the steel bar 2, and a first force sensor is installed on the hydraulic cylinder 73. The first force sensor detects the acting force of the pressing block 77 on the steel bar 2 on the hydraulic cylinder 73, and the second strain gauge detects the strain value of the steel bar 2. According to the detection value of the first force sensor, the detection value of the second strain gauge, and the acting force applied by the hydraulic cylinder 73, an impact protection test is carried out on the steel bar 2.

[0056] Example 4

[0057] Based on Example 1, it further includes:

[0058] A second force sensor: The second force sensor is arranged at one end of the threaded block 5 close to the fixed shell 3 and is used to detect the extrusion force between the threaded block 5 and the fixed shell 3;

[0059] An alarm: The alarm is arranged on the fixed shell 3;

[0060] A controller: The controller is electrically connected to the second force sensor and the alarm;

[0061] The controller controls the operation of the alarm based on the detection value of Force Sensor 2, including the following methods:

[0062] The controller calculates the connection stability coefficient between the threaded block 5 and the steel bar 2 according to the extrusion force between the threaded block 5 and the fixed shell 3 detected by Force Sensor 2 and Formula (1). The controller compares the calculated connection stability coefficient between the threaded block 5 and the steel bar 2 with the preset stability coefficient. If the calculated connection stability coefficient between the threaded block 5 and the steel bar 2 is less than the preset stability coefficient, the controller controls the alarm to give an alarm;

[0063]

[0064] Wherein, K is the connection stability coefficient between the threaded block 5 and the steel bar 2, E is the elastic coefficient of the threaded block 5, L is the pitch diameter of the thread in the threaded block 5, F is the detection value of Force Sensor 2, C is the minor diameter of the thread in the threaded block 5, m is the number of thread turns in the threaded block 5, and S is the thread tooth thickness in the threaded block 5;

[0065] The beneficial effects of the above technical solution are:

[0066] Force Sensor 2 is arranged at one end of the threaded block 5 close to the fixed shell 3 to detect the extrusion force between the threaded block 5 and the fixed shell 3. The controller calculates the connection stability coefficient between the threaded block 5 and the steel bar 2 according to the extrusion force between the threaded block 5 and the fixed shell 3 detected by Force Sensor 2 and Formula (1). The controller compares the calculated connection stability coefficient between the threaded block 5 and the steel bar 2 with the preset stability coefficient. If the calculated connection stability coefficient between the threaded block 5 and the steel bar 2 is less than the preset stability coefficient, the controller controls the alarm to give an alarm, reminding the user to replace the threaded block 5 in time to avoid relative displacement between the threaded block 5 and the steel bar 2, affecting the impact protection test of the steel bar 2.

[0067] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these changes and modifications.

Claims

1. A prestressed steel bar impact protection test device, characterized in that, Comprising: A positioning mechanism (4), the positioning mechanism (4) is installed with a fixing mechanism, both the positioning mechanism (4) and the fixing mechanism are connected to the steel bar assembly, and the fixing mechanism is connected with a testing mechanism; The steel bar assembly includes concrete (1), in which steel bars (2) are cast, and the threaded end of the steel bar (2) is threadedly connected with a threaded block (5); The fixing mechanism includes a fixing shell (3), the side end of the fixing shell (3) is in contact with the threaded block (5), through holes are provided through the upper and lower ends of the fixing shell (3) to form a fixing cavity (31), the fixing shell (3) is fixedly connected with a force-applying block (32), and a through hole is provided through one end of the fixing shell (3) away from the force-applying block (32), and the through hole communicates with the fixing cavity (31); The positioning mechanism (4) includes a base (41), on which the concrete (1) is placed, a number of guiding and positioning plates (43) are evenly arranged at intervals on the upper end of the base (41), through holes are provided through the left and right ends of the guiding and positioning plates (43) to form guiding cavities (44), and the guiding cavities (44) are slidably connected with the fixing shell (3); The positioning mechanism (4) further includes a positioning plate (45), which is fixedly installed on the upper left side of the base (41), a positioning groove (42) is provided on the upper end of the positioning plate (45), the positioning plate (45) is in contact with the concrete (1), and the steel bar (2) passes through the positioning groove (42) and the through hole in sequence and communicates with the outside; A quick-release mechanism is fixedly arranged in the through hole, the quick-release mechanism includes a first fixing sleeve (51), the first fixing sleeve (51) is rotatably arranged in the through hole, through holes are provided through the left and right ends of the first fixing sleeve (51) to form first mounting holes (56), a number of clamping components are circumferentially and evenly arranged in the first mounting holes (56), the clamping components are used for clamping the steel bar (2), the first fixing sleeve (51) is rotatably connected with a second fixing sleeve (52), through holes are provided through the left and right ends of the second fixing sleeve (52) to form second mounting holes (510), the second mounting holes (510) communicate with the first mounting holes (56), and the first mounting holes (56) cooperate with the steel bar (2); The first fixing sleeve (51) is connected with a driving component, the driving component is connected with a retaining component, the retaining component is used for limiting the extrusion component, the extrusion component includes two rotating rods (511), the two rotating rods (511) are rotatably arranged in the movable groove (513), and the rotating rods (511) are in contact with the airbag (512) in the movable groove (513), the movable grooves (513) are symmetrically arranged on the upper and lower sides of one end of the second fixing sleeve (52) away from the first fixing sleeve (51), the airbag (512) is connected with a pneumatic rod (516) through a communication pipeline (514), the pneumatic rod (516) is fixedly connected with an extrusion plate (518), the extrusion plate (518) is slidably arranged in the first sliding groove (519), the first sliding grooves (519) are symmetrically arranged on the upper and lower sides of the second mounting holes (510), and the extrusion plate (518) squeezes and fixes the steel bar.

2. The prestressed steel bar impact protection test device according to claim 1, characterized in that, On the upper right side of the base (41), a damper (6) is fixedly installed. One end of the steel bar (2) close to the damper (6) is provided with a buffer block, which is arranged corresponding to the damper (6). Strain gauges I (33) are connected to both the steel bar (2) and the force application block (32), and the strain gauges I (33) on the steel bar (2) and the force application block (32) are connected in series.

3. The prestressed steel bar impact protection test device according to claim 1, characterized in that, It further includes a multi-directional test mechanism. The multi-directional test mechanism includes a base (7). A connection groove (71) and a test groove (72) are fixedly provided at the upper end of the base (7). Concrete (1) is fixedly connected in the connection groove (71). The test groove (72) is slidably connected to a first sliding block (74). The first sliding block (74) is fixedly connected to a hydraulic cylinder (73). The hydraulic cylinder (73) is fixedly installed on the base (7). The first sliding block (74) is provided with a fixing hole (78), and the fixing hole (78) is fixedly connected to the steel bar (2). A second sliding groove (76) is provided on the first sliding block (74). The second sliding groove (76) is slidably connected to a second sliding block (79). An adjusting rod (710) is fixedly connected to the second sliding block (79). The adjusting rod (710) is fixedly connected to a pressing block (77). A pressing groove (75) on the pressing block (77) cooperates with the steel bar (2). A support rod (711) is rotatably connected to the second sliding block (79), and the support rod (711) is rotatably connected to the base (7).

4. A test method based on a prestressed steel bar impact protection test device according to any one of claims 1-3, characterized in that: It includes the following steps: Step 1: First, apply a load to the steel bar (2), then pour concrete (1) on the steel bar (2) under load, and cure it to the designed strength. Step 2: Place the cured concrete (1) on the base (41). The steel bar (2) passes through the positioning groove (42) and the through hole and is threadedly connected to the threaded block (5). Step 3: Apply a load to the force application block (32) to conduct a breaking impact test. Step 4: The strain gauges I (33) on the steel bar (2) and the force application block (32) measure the deformation value of the steel bar (2). Step 5: The prestressed steel bar impact protection test is reflected by the relationship between the load value applied on the force application block (32) and the deformation value of the steel bar (2).

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