Device for testing drawing bearing capacity of shear connector of composite beam bridge

Abstract

The utility model discloses a composite beam bridge shear connector drawing bearing capacity test device, which comprises a portal frame, a pressurizing mechanism, a force sensor, a composite beam bridge equivalent test piece, a fixing frame and a supporting seat, the bottom end of the pressurizing mechanism is fixed with the top end of the force sensor, and the bottom end of the force sensor is hinged with the top end of the fixing frame through a pivot; a composite beam bridge equivalent test piece is arranged in the fixed frame, and the bottoms of the two ends of the equivalent beam are in movable contact with the two supporting seats respectively. The device has the advantages that the pressurizing mechanism downwards draws the equivalent test piece of the composite beam bridge through the fixing frame, and in the process, the two ends of the equivalent beam are bent and deformed under the support of the supporting seats, so that the shear connecting piece is subjected to vertical force in the drawing process and is also subjected to transverse force generated by bending of the beam; and the actual stress state of the shear connector in the composite beam bridge is better met, so that the drawing bearing capacity test of the shear connector is more comprehensive, real and reliable.

Description

Technical field:

[0001] The utility model relates to the technical field of shear connector testing, in particular to a pull-out bearing capacity testing device for shear connectors of a composite beam bridge. Background technology:

[0002] The steel-concrete composite beam structure has the advantages of both steel and concrete. It uses materials reasonably and economically, has a fast construction speed, and is highly practical. It is widely used in the fields of roads, bridges, and construction. Shear connectors are key components that affect the stress performance of steel and concrete composite structures and ensure that dissimilar materials work together to improve comprehensive performance.

[0003] Shear connectors not only transmit shear force between concrete and steel beams, but also need to be able to bear the pull-out force in the vertical direction of the steel-concrete interface to prevent lifting. This effect is particularly prominent in the negative bending moment area of ​​the composite beam. However, in actual engineering, shear connectors are not only subject to the vertical constraint force imposed by the surrounding concrete during the pull-out process, but also to the lateral force generated by the bending deformation of the beam. At present, the pull-out bearing capacity test device of shear connectors of composite beam bridges regards concrete as an infinite rigid base, and ignores the influence of the lateral force generated by the bending deformation of the concrete beam on the pull-out bearing capacity of the shear connector. It is impossible to reproduce the actual stress state of the shear connector in the composite beam bridge, and it is impossible to accurately obtain the true and accurate pull-out bearing capacity of the shear connector. Utility model content:

[0004] The utility model aims to provide a pull-out bearing capacity testing device for shear connectors of a composite beam bridge.

[0005] The utility model is implemented by the following technical scheme: a pull-out bearing capacity test device for shear connectors of a composite beam bridge, which comprises a gantry, a pressurizing mechanism, a force sensor, a composite beam bridge equivalent test piece, a fixed frame and a support seat, wherein the pressurizing mechanism is arranged at the middle of the bottom end of the crossbeam of the gantry, and two support seats are arranged below the gantry, and the two support seats are symmetrically arranged about the pressurizing mechanism; the bottom end of the pressurizing mechanism is fixed to the top end of the force sensor, and the bottom end of the force sensor is hinged to the top end of the fixed frame by a pivot; an equivalent test piece of a composite beam bridge is arranged inside the fixed frame, and the lower frame of the fixed frame is fixedly connected to the equivalent test piece of the composite beam bridge, and the two ends of the equivalent beam of the equivalent test piece of the composite beam bridge extend to the outside of the two ends of the fixed frame, and the bottoms of the two ends of the equivalent beam are respectively in active contact with the two support seats.

[0006] Furthermore, a pair of first displacement sensors symmetrically arranged on the left and right are arranged at the bottom of the equivalent beam between the support seat and the fixing frame.

[0007] Furthermore, the length of the equivalent beam is L, and the distance between the first displacement sensor and an adjacent end of the equivalent beam is 1 / 4L.

[0008] Furthermore, the support seat includes a base, a bracket and a roller, the bracket is fixed on the top of the base, the roller is rotatably arranged laterally on the top of the bracket, the axis of the roller is vertically arranged relative to the equivalent beam, and the top surface of the roller contacts the bottom of the equivalent beam.

[0009] Furthermore, the bracket includes a steel plate, a groove vertically arranged relative to the equivalent beam is arranged on the top of the steel plate, and the roller is movably arranged in the groove.

[0010] Furthermore, the composite beam bridge equivalent specimen includes an I-beam, a shear connector and the equivalent beam, wherein the I-beam is fixed to the top of the lower frame of the fixed frame, the web of the I-beam is arranged parallel to the side frame of the fixed frame, an equivalent beam is arranged between the top of the I-beam and the bottom of the upper frame of the fixed frame, the shear connector whose bottom end is fixed to the I-beam is pre-embedded in the middle of the bottom end of the equivalent beam, and the shear connector is arranged at the center of the top end of the I-beam.

[0011] Furthermore, a pair of second displacement sensors arranged left and right are respectively provided at the bottom of the equivalent beam at both ends of the I-beam.

[0012] Furthermore, a pair of third displacement sensors are respectively provided at both ends of the upper wing plate of the I-beam and are arranged symmetrically with respect to the web.

[0013] Furthermore, a fourth displacement sensor is provided at a position at the bottom of the fixing frame corresponding to the bottom center of the lower wing plate of the I-beam.

[0014] Furthermore, a fifth displacement sensor is respectively arranged on both sides of the middle portion of the web.

[0015] Furthermore, the fixed frame includes an upper frame, a lower frame, a side frame and a connecting plate. The side frames are fixed to the bottom of both sides of the upper frame and the top of both sides of the lower frame. A connecting plate is respectively arranged between the two corresponding upper and lower side frames, and the connecting plate is connected to the corresponding side frame by bolts.

[0016] The advantages of the utility model are as follows: the pressurizing mechanism pulls the equivalent test piece of the composite beam bridge downward through the fixed frame. During this process, both ends of the equivalent beam are bent and deformed under the support of the support seat, so that the shear connector is not only subjected to the vertical force during the pulling process, but also to the lateral force caused by the bending of the beam, which is more in line with the actual stress state of the shear connector in the composite beam bridge, making the pull-out bearing capacity test of the shear connector more comprehensive, true and reliable. Description of the drawings:

[0017] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0018] Figure 2 Schematic diagram of displacement sensor distribution.

[0019] Figure 3 It is a schematic diagram of the fixed frame structure.

[0020] Figure 4 It is a schematic diagram of the support seat structure.

[0021] Figure 5 Schematic diagram of the equivalent specimen structure of the composite beam bridge.

[0022] Tag Name

[0023] 1-gantry, 2-pressurizing mechanism, 3-force sensor, 4-combined beam bridge equivalent specimen, 41-equivalent beam, 42-I-beam, 421-upper wing plate, 422-web plate, 423-lower wing plate, 43-shear connector, 5-fixed frame, 51-upper frame, 52-lower frame, 53-side frame, 54-connecting plate, 55-bolt, 6-support seat, 61-base, 62-bracket, 63-roller, 64-groove, 8-pivot, 9-first displacement sensor, 10-second displacement sensor, 11-third displacement sensor, 12-fourth displacement sensor, 13-fifth displacement sensor. Specific implementation method:

[0024] In the description of the present invention, it should be noted that if the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, if the terms "first", "second", "third" appear, they are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0025] like Figures 1 to 5As shown, a pull-out bearing capacity test device for shear connectors of a composite beam bridge comprises a gantry 1, a pressurizing mechanism 2, a force sensor 3, an equivalent test piece of a composite beam bridge 4, a fixing frame 5 and a support seat 6, wherein a pressurizing mechanism 2 is arranged in the middle of the bottom end of the crossbeam of the gantry 1, and the pressurizing mechanism 2 is a hydraulic cylinder; the bottom end of the pressurizing mechanism 2 is fixed to the top end of the force sensor 3, and the bottom end of the force sensor 3 is hinged to the top end of the fixing frame 5 through a pivot 8, and the axis of the pivot 8 is arranged vertically relative to the equivalent beam 41; the pressure applied by the pressurizing mechanism 2 can be detected by the force sensor 3; specifically, hinge seats are fixed at the bottom of the force sensor 3 and the top of the fixing frame 5 respectively, and the pivot 8 is inserted between the hinge holes of the two hinge seats.

[0026] A composite beam bridge equivalent specimen 4 is arranged inside the fixed frame 5, and the lower frame 52 of the fixed frame 5 is fixedly connected to the composite beam bridge equivalent specimen. The pressure mechanism can pull the composite beam bridge equivalent specimen downward through the lower frame by applying pressure to the fixed frame to realize the shear connector pull-out test. In this embodiment, the composite beam bridge equivalent specimen 4 includes an I-beam 42, a shear connector 43 and an equivalent beam 41. The I-beam 42 is fixed on the top of the lower frame 52 of the fixed frame 5, and the web 422 of the I-beam 42 is arranged parallel to the side frame 53 of the fixed frame 5. The equivalent beam 41 is arranged between the top of the I-beam 42 and the bottom of the upper frame 51 of the fixed frame 5, and the shear connector 43 whose bottom end is fixed to the I-beam 42 is pre-embedded in the middle of the bottom end of the equivalent beam 41. The lower frame is fixedly connected to the I-beam of the composite beam bridge equivalent specimen by bolts.

[0027] Two support seats 6 are arranged below the gantry 1, and the two support seats 6 are symmetrically arranged about the pressure mechanism 2; the two ends of the equivalent beam 41 extend to the outside of the two ends of the fixed frame 5, and the bottoms of the two ends of the equivalent beam 41 are respectively in active contact with the two support seats 6. Specifically, the support seat 6 includes a base 61, a bracket 62 and a roller 63. The bracket 62 is fixed on the top of the base 61, and a roller 63 arranged horizontally is rotatably arranged on the top of the bracket 62. The axis of the roller 63 is arranged vertically relative to the equivalent beam 41, and the top surface of the roller 63 is in contact with the bottom of the equivalent beam 41; the two ends of the equivalent beam 41 are hinged to the base 61 through the roller 63 to ensure that the equivalent beam 41 can be bent and deformed freely. The bracket 62 includes a steel plate, which is fixed to the top of the base 61 by bolts 55. A groove 64 arranged vertically relative to the equivalent beam 41 is arranged on the top of the steel plate, and the roller 63 is movably arranged in the groove 64. The two ends of the equivalent beam 41 are supported between two rollers 63. When the pressure mechanism 2 applies vertical force, it is also subjected to the lateral force generated by the bending of the beam, so that the pulling process of the shear connector 43 is more consistent with its actual stress state in the composite beam bridge, and better reflects the pulling damage of the shear connector 43 under complex stress state.

[0028] A pair of first displacement sensors 9 arranged symmetrically on the left and right are arranged at the bottom of the equivalent beam 41 between the support seat 6 and the fixed frame 5; the length of the equivalent beam 41 is L, and the distance between the first displacement sensor 9 and the adjacent end of the equivalent beam 41 is 1 / 4L. A pair of second displacement sensors 10 arranged on the left and right are respectively arranged at the bottom of the equivalent beam 41 at both ends of the I-beam 42. The flexural deformation of the equivalent beam 41 during loading can be measured by the first displacement sensor 9 and the second displacement sensor 10. A pair of third displacement sensors 11 arranged symmetrically on the left and right about the web 422 are respectively arranged at both ends of the upper wing plate 421 of the I-beam 42, and the displacement of the two ends of the upper wing plate 421 can be measured by the third displacement sensor 11. A fourth displacement sensor 12 is arranged at the bottom of the fixed frame 5 at a position corresponding to the bottom center of the lower wing plate 423 of the I-beam 42, and the shear connector 43 and the fourth displacement sensor 12 are respectively arranged at the top center and the bottom center of the I-beam 42, corresponding to each other up and down; therefore, the displacement of the shear connector 43 can be measured by the fourth displacement sensor 12. A fifth displacement sensor 13 is provided on both sides of the middle of the web 422, and the fifth displacement sensor 13 can be used to measure the relative displacement between the shear connector 43 and the span of the concrete beam. The first to fifth displacement sensors are all 5G103 linear displacement sensors.

[0029] The fixing frame 5 includes an upper frame 51, a lower frame 52, a side frame 53 and a connecting plate 54. The side frames 53 are fixed to the bottom of both sides of the upper frame 51 and the top of both sides of the lower frame 52. A connecting plate 54 is respectively arranged between the two corresponding upper and lower side frames 53, and the connecting plate 54 is connected to the corresponding side frame 53 by bolts 55. In order to facilitate connection, connecting holes are pre-opened on the upper frame 51, the lower frame 52, the side frame 53 and the connecting plate 54, and corresponding connecting holes are opened on the lower wing plate 423 of the I-beam 42 and the lower frame 52; the upper and lower frames are detachably connected to the connecting plate 54 through the side frame 53 and the bolts 55, which is convenient for disassembly and assembly, and different composite beams can be replaced. During assembly, first align the bottom end of the shear connector embedded in the equivalent beam with the center of the I-beam and fix it by welding; then move the upper frame to the top of the equivalent beam so that the side frames 53 on both sides thereof correspond to the side frames 53 on both sides of the lower frame 52; finally, fix the connecting plate 54 between the corresponding upper and lower side frames 53 by bolts 55.

[0030] Test process:

[0031] In the first step, the composite beam bridge equivalent specimen 4 is assembled with the fixing frame 5, and the I-beam 42 and the lower frame are fixed by bolts to ensure a firm connection;

[0032] The second step is to move the composite beam bridge equivalent specimen 4 and the fixed frame 5 as a whole to the top of the two support seats 6, so that the centers of the pressure mechanism 2 and the fixed frame 5 correspond to each other, and then lower the composite beam bridge equivalent specimen 4 and the fixed frame 5 as a whole until the two ends of the equivalent beam 41 contact the roller 63 on the top of the base 61;

[0033] The third step is to connect the bottom of the force sensor 3 and the hinge seat at the top of the fixed frame 5 through the pivot 8 to form a loading control system;

[0034] Step 4: Install each displacement sensor to the corresponding position of the equivalent beam 41 and the I-beam 42;

[0035] The fifth step is to calibrate the force sensor 3 and each displacement sensor to ensure their accuracy; start the pressurizing mechanism 2 for preloading, and observe the detection values ​​of each sensor to ensure that all components are working properly before the test starts;

[0036] The sixth step is to gradually increase the load of the pressurizing mechanism 2 and record relevant data, including force changes, displacement, etc.; monitor the state of the composite beam bridge equivalent specimen 4 during the test to ensure the safety of the test.

[0037] Step 7: After the composite beam bridge equivalent specimen 4 is destroyed, the loading of the pressurizing mechanism 2 is stopped and unloading is performed.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solution deviate from the scope of the technical solution of the embodiments of the utility model.

Claims

1. A pull-out bearing capacity test device for shear connectors of composite beam bridges, characterized in that: It includes a gantry, a pressurizing mechanism, a force sensor, a combined beam bridge equivalent specimen, a fixed frame and a support seat. The pressurizing mechanism is arranged in the middle of the bottom end of the crossbeam of the gantry, and two support seats are arranged below the gantry, and the two support seats are symmetrically arranged about the pressurizing mechanism; the bottom end of the pressurizing mechanism is fixed to the top end of the force sensor, and the bottom end of the force sensor is hinged to the top end of the fixed frame through a pivot; a combined beam bridge equivalent specimen is arranged inside the fixed frame, and the lower frame of the fixed frame is fixedly connected to the combined beam bridge equivalent specimen, and the two ends of the equivalent beam of the combined beam bridge equivalent specimen extend to the outside of the two ends of the fixed frame, and the bottoms of the two ends of the equivalent beam are respectively in active contact with the two support seats.

2. A pull-out bearing capacity test device for shear connectors of composite beam bridges according to claim 1, characterized in that: A pair of first displacement sensors symmetrically arranged on the left and right are arranged at the bottom of the equivalent beam between the support seat and the fixing frame.

3. A pull-out bearing capacity test device for shear connectors of composite beam bridges according to claim 2, characterized in that: The length of the equivalent beam is L, and the distance between the first displacement sensor and an adjacent end of the equivalent beam is 1 / 4L.

4. A pull-out bearing capacity test device for shear connectors of composite beam bridges according to claim 1, characterized in that: The support seat includes a base, a bracket and a roller. The bracket is fixed on the top of the base. The roller arranged laterally is rotatably provided on the top of the bracket. The axis of the roller is arranged vertically relative to the equivalent beam, and the top surface of the roller contacts the bottom of the equivalent beam.

5. A pull-out bearing capacity test device for shear connectors of composite beam bridges according to claim 4, characterized in that: The support comprises a steel plate, a groove vertically arranged relative to the equivalent beam is arranged on the top of the steel plate, and the roller is movably arranged in the groove.

6. A pull-out bearing capacity test device for shear connectors of composite beam bridges according to any one of claims 1 to 5, characterized in that: The composite beam bridge equivalent specimen includes an I-beam, a shear connector and the equivalent beam. The I-beam is fixed to the top of the lower frame of the fixed frame, the web of the I-beam is arranged parallel to the side frame of the fixed frame, and the equivalent beam is arranged between the top of the I-beam and the bottom of the upper frame of the fixed frame. The shear connector whose bottom end is fixed to the I-beam is pre-embedded in the middle of the bottom end of the equivalent beam, and the shear connector is arranged at the center of the top end of the I-beam.

7. A pull-out bearing capacity test device for shear connectors of composite beam bridges according to claim 6, characterized in that: A pair of second displacement sensors arranged left and right are respectively provided at the bottom of the equivalent beam at both ends of the I-beam.

8. A pull-out bearing capacity test device for shear connectors of composite beam bridges according to claim 6, characterized in that: A pair of third displacement sensors are respectively arranged at both ends of the upper wing plate of the I-beam and are arranged symmetrically with respect to the web.

9. A pull-out bearing capacity test device for shear connectors of composite beam bridges according to claim 6, characterized in that: A fourth displacement sensor is arranged at a position at the bottom of the fixing frame corresponding to the bottom center of the lower wing plate of the I-beam.

10. A pull-out bearing capacity test device for shear connectors of composite beam bridges according to claim 6, characterized in that: A fifth displacement sensor is respectively arranged on both sides of the middle portion of the web.

11. A pull-out bearing capacity test device for shear connectors of composite beam bridges according to claim 6, characterized in that: The fixed frame includes an upper frame, a lower frame, a side frame and a connecting plate. The side frames are fixed to the bottom of both sides of the upper frame and the top of both sides of the lower frame. A connecting plate is respectively arranged between the two corresponding upper and lower side frames, and the connecting plate is connected to the corresponding side frame by bolts.

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