Testing device for loading of upper layer and lower layer of double-layer steel truss girder

Abstract

The utility model discloses a test device for upper and lower layer loading of a double-layer steel truss girder, which comprises a four-column type loading hydraulic machine, and further comprises a top plate distribution beam, a jack, a bottom plate distribution beam and a rigid spring from top to bottom, the top plate distribution beam is horizontally arranged, the middle of the top plate distribution beam is fixedly connected with the lower end of a piston rod of the loading hydraulic machine, and the top plate distribution beam is pressed on a double-layer steel truss girder top plate in use and used for applying pressure load to the double-layer steel truss girder top plate. The bottom plate distribution beam is horizontally arranged under the top plate distribution beam. The rigid springs are connected between the left end and the right end of the top plate distribution beam and the left end and the right end of the bottom plate distribution beam. During use, the bottom plate distribution beam is arranged between the upper layer and the lower layer of the double-layer steel truss in a penetrating mode and pressed downwards, and the bottom plate distribution beam is used for applying pressure loads to the bottom plate of the double-layer steel truss. The multiple jacks are arranged between the top plate distribution beam and the bottom plate distribution beam.

Description

TECHNICAL FIELD

[0001] The utility model belongs to civil engineering test device technical field, concretely relates to a test device for loading on the upper and lower layers of double-layer steel truss beam. BACKGROUND

[0002] Double-layer steel truss beam bridge has been widely applied in the fields of urban traffic, expressway and railway due to its obvious advantages. The double-layer steel truss beam makes full use of the vertical space of the bridge, improves the traffic capacity and passing efficiency, has excellent mechanical properties and stability, and can bear larger load and deformation. The overall structure is affected by the randomness and asymmetry of the upper and lower loads, and the steel truss beam will be accompanied by bending, shear lag, torsion and distortion effect, and the spatial stress state is particularly prominent. Model test is the most convenient means to study the overall spatial effect of this kind of structure, and the current loading device for double-layer steel truss beam only acts on the upper bridge deck (top plate), and cannot realize the simultaneous loading of the upper and lower bridge decks of the double-layer steel truss beam. Figure 3 Simultaneous loading diagram of upper and lower bridge decks of double-layer steel truss beam). CONTENT OF UTILITY MODEL

[0003] In order to solve the problem that the upper and lower bridge decks of the double-layer steel truss beam cannot be loaded simultaneously at present, the utility model provides a test device for loading on the upper and lower layers of double-layer steel truss beam, which provides technical support for the actual load test research of this kind of structure.

[0004] Therefore, the utility model adopts the following technical scheme:

[0005] A test device for loading on the upper and lower layers of double-layer steel truss beam, comprising a four-column loading hydraulic machine, further comprising a top plate distribution beam, a jack, a bottom plate distribution beam and a rigid spring from top to bottom;

[0006] The top plate distribution beam is horizontally arranged and fixedly connected with the lower end of the piston rod of the loading hydraulic machine in the middle part, and the top plate distribution beam is used to apply pressure load to the top plate of the double-layer steel truss beam when the top plate distribution beam is pressed on the top plate of the double-layer steel truss beam;

[0007] The bottom plate distribution beam is horizontally arranged below the top plate distribution beam, and the rigid spring comprises a plurality of springs and is connected between the left and right ends of the top plate distribution beam and the bottom plate distribution beam; when in use, the bottom plate distribution beam is arranged between the top plate and the bottom plate of the double-layer steel truss beam and presses the bottom plate of the double-layer steel truss beam, and the bottom plate distribution beam is used to apply pressure load to the bottom plate of the double-layer steel truss beam;

[0008] The jack comprises a plurality of jacks and is arranged between the top plate distribution beam and the bottom plate distribution beam.

[0009] Furthermore, the bottom surface of the top plate distribution beam is provided with two spaced first loading blocks, and the bottom surface of the bottom plate distribution beam is provided with two spaced second loading blocks, the distance between the first loading blocks and the second loading blocks is adjustable.

[0010] Furthermore, the top plate distribution beam and the bottom plate distribution beam are I-beam structures.

[0011] Furthermore, pressure plates are respectively padded on the top and bottom surfaces of the jack.

[0012] The beneficial effects of this utility model are as follows:

[0013] 1. By setting up jacks between the top and bottom slab distribution beams, the vertical load of the hydraulic press can be applied to the bottom slab of the double-layer steel truss girder. Two infinitely rigid distribution beams (with adjustable loading positions) are placed on the top and bottom slabs of the double-layer steel truss girder. The vertical hydraulic press applies the load to the top slab distribution beams. By starting the hydraulic jacks and controlling their readings, the vertical load of the hydraulic press can be transferred to the bottom slab of the double-layer steel truss girder.

[0014] 2. The top plate distribution beam and the bottom plate distribution beam are connected by rigid springs. Using rigid springs to connect the bottom plate distribution beam reduces the impact of the bottom plate distribution beam's self-weight under load, and the structure is easy to disassemble, which facilitates the assembly of the device. Attached Figure Description

[0015] Figure 1 This is a front view of the structure of the experimental device of this utility model;

[0016] Figure 2 This is a side view of the structure of the experimental device of this utility model;

[0017] Figure 3 This is a schematic diagram of the loading of the top and bottom plates of the double-layer steel truss beam;

[0018] Figure 4 This is a schematic diagram of the overall loading and stress distribution of a double-layer steel truss beam;

[0019] Figure 5 This is a schematic diagram of the stress distribution beam in the top slab;

[0020] Figure 6 This is a schematic diagram of the stress distribution beam on the base plate;

[0021] Figure 7 This is a schematic diagram of the stress on a double-layer steel truss beam;

[0022] Figure 8 This is a schematic diagram of the working forces of a hydraulic jack;

[0023] In the figure: 1-filter, 2-liquid-filled oil tank, 3-main oil cylinder, 4-first round nut, 5-cross beam, 6-flange plate, 7-piston rod, 8-pressure sensor, 9-first pressing plate, 10-second round nut, 11-stand, 12-top plate distribution beam, 13-first loading block, 14-second pressing plate, 15-piston top plate, 16-piston top rod, 17-oil cylinder, 18-rigid spring, 19-second loading block, 20-bottom plate distribution beam, 21-oil pipe, 22-distribution valve, 23-pressure gauge, 24-motor, 25-pressure control valve, 26-oil pump. DETAILED DESCRIPTION

[0024] The utility model will be further described below in combination with the drawings and specific embodiments:

[0025] As shown in Figure 1 and 2 The utility model includes the following components:

[0026] Filter 1: can effectively remove the impurities and pollutants in oil, reduce the wear and tear of key components such as valve body, pump, hydraulic cylinder, and reduce the failure rate caused by impurities blocking the valve.

[0027] Liquid-filled oil tank 2: store hydraulic oil, cool oil, sediment impurities and provide bubble separation to reduce the cavitation phenomenon in the hydraulic system, and ensure the stable operation of the system.

[0028] Main oil cylinder 3: provide the power source for the work of the hydraulic machine through the action of hydraulic oil, and the piston rod 7 of the main oil cylinder 3 generates linear motion under the action of pressure oil to provide the corresponding pressure source.

[0029] First round nut 4: the first round nut bears part of the gravity and other forces of the slider during the movement, and transmits these forces to the stand of the hydraulic machine.

[0030] Cross beam 5: the pressure generated by the hydraulic cylinder is transmitted to the cross beam 5 through the slider, and the cross beam 5 uniformly distributes the pressure to the four stands, ensuring the stability and uniform stress of the entire hydraulic machine structure.

[0031] Flange plate 6: during the operation of the hydraulic machine, the flange plate 6 can transmit the torque generated by the hydraulic cylinder to the slider or other working components, ensure the effective transmission and distribution of force, and the flange plate 6 is made of high-strength material, which can withstand the high pressure generated during the operation of the hydraulic machine, and ensure the stability and safety of the connecting components.

[0032] Piston rod 7: used for converting the pressure provided by the hydraulic oil into mechanical energy, and providing guiding transmission to the lower pressing plate. During the operation of the hydraulic machine, not only the force is transmitted, but also the weight of the slider and other components is supported, and the stability of the hydraulic machine is maintained.

[0033] Pressure sensor 8: used to monitor the pressure value in the hydraulic system, ensure that the hydraulic press works within the set pressure range, prevent system overload, protect key components of the hydraulic press from damage and record pressure data during the operation of the hydraulic press.

[0034] First pressure plate 9: used to connect the top plate distribution beam 12 and evenly distribute the pressure of the hydraulic press to the top plate distribution beam 12.

[0035] First round nut 4: the first round nut 4 bears part of the gravity and other forces of the slider during movement, and transmits these forces to the column of the hydraulic press.

[0036] Column 11: provides a solid support frame for the crossbeam and workbench of the hydraulic press, ensuring the stability of the entire machine. The column 11 bears the huge pressure generated by the hydraulic cylinder during the operation of the hydraulic press.

[0037] Top plate distribution beam 12: evenly distributes the pressure generated by the hydraulic press to the top plate of the double-layer steel truss, and uses I-beam for distribution, so that the first loading block can change the loading position when loading horizontally on the steel truss.

[0038] First loading block 13: evenly applies the pressure on the top plate distribution beam 12 to the top plate of the double-layer steel truss, and changes the loading position by adjusting.

[0039] Second pressure plate 14: adjusts the distance between the split hydraulic press and the top plate, and evenly applies the pressure received to the top plate, used to adjust the pressure received by the top plate.

[0040] Piston top plate 15: increases the contact area of the jack with the distribution beam, so that the pressure generated by the jack can be evenly applied to the top plate distribution beam.

[0041] Piston top rod 16: converts the pressure provided in the oil cylinder into mechanical energy and moves upward, playing a role in force transmission and movement during the operation of the jack.

[0042] Oil cylinder 17: the oil cylinder is the part of the hydraulic jack that contains hydraulic oil and generates thrust. The piston moves within the oil cylinder, thereby extending or retracting the top rod.

[0043] Rigid spring 18: fixes the bottom plate distribution beam 20, adjusts the bottom plate distribution beam 20, and reduces the influence of the self-weight of the bottom plate distribution beam 20.

[0044] Second loading block 19: evenly applies the pressure on the bottom plate distribution beam 20 to the bottom plate of the double-layer steel truss, and changes the loading position by adjusting.

[0045] 20. Bottom plate distribution beam: evenly distribute the pressure generated by the hydraulic machine to the bottom plate of the double-layer steel truss, use I-beam for distribution, so that the loading block can change the loading position when the steel truss is loaded horizontally.

[0046] Oil pipe 21: used for connecting the oil pump and oil cylinder of the hydraulic jack, ensuring that the hydraulic oil can flow under the pressure generated by the oil pump, thereby transmitting the pressure to the piston in the oil cylinder.

[0047] Flow distribution and flow collection valve 22: divides a single oil flow into multiple branches, controls the flow of each branch, and ensures that each oil cylinder or actuator obtains appropriate working pressure and speed.

[0048] Pressure gauge 23: used to detect the pressure generated by the jack to prevent excessive pressure from damaging the element.

[0049] Electric motor 24: provides energy source for the oil pump of the jack.

[0050] Pressure control valve 25: adjusts the maximum pressure generated by the jack.

[0051] Oil pump 26: the oil pump is the power source of the hydraulic system, which converts mechanical energy into hydraulic energy to provide pressure and flow for the entire hydraulic system, so that the hydraulic oil can circulate in the system and transmit energy.

[0052] The design principle of the utility model is as follows:

[0053] (1) Based on the existing extension and compression type four-column hydraulic machine, a bottom plate distribution beam is added

[0054] Use the existing four-column loading hydraulic machine, first fix the top plate distribution beam 12 on the pressure plate of the loading machine, then pass the bottom plate distribution beam 20 from the web and press it on the corresponding position of the bottom plate of the double-layer steel truss. In order to reduce the influence of the self-weight of the bottom plate distribution beam 20 on the loading, rigid springs 18 are added between the top plate distribution beam 12 and the bottom plate distribution beam 20.

[0055] (2) Use separate hydraulic jacks to apply vertical load to the top and bottom plate distribution beams

[0056] Two hydraulic jacks are used, which are placed on the top and bottom plate distribution beams respectively. By changing the readings of the two symmetrical jacks, the application of load to the bottom plate of the double-layer steel truss is realized.

[0057] (3) Consider the pressure control of the separate hydraulic jacks

[0058] Two hydraulic jacks use the same pump source, and a hydraulic pump with synchronous control function is used. Before the test, the pressure control valve is adjusted to make the jack provide the required pressure.

[0059] The stress principle of the utility model is as follows:

[0060] As Figures 3 to 8 shown in the figure, the top plate distribution beam 12 is fixed on the loading device, the bottom plate distribution beam 20 is connected with the top plate through the rigid spring 18, and the specific stress process is as follows:

[0061] (1) the hydraulic machine and the hydraulic jack start working at the same time, first, when the top plate distribution beam 12 acts downward, the force of the top plate distribution beam 12 acting downward is reduced due to the existence of the hydraulic jack, and the reduced force is distributed to the bottom plate of the double-layer steel truss.

[0062] (2) the parameter of the hydraulic jack is set so that the pressure applied by the hydraulic jack is just the pressure required by the top plate of the double-layer steel truss, assuming that the overall force required to be loaded is P, the parameter of the hydraulic jack is adjusted so that the maximum pressure is P / 6, during the working process of the overall device, the left and right hydraulic jacks will generate a pressure of P / 6, at this time, the hydraulic jack is supported by the bottom plate distribution beam 20, and an interaction force of P / 6 is generated between the hydraulic jack and the top plate of the double-layer steel truss, and the force generated on the top plate distribution beam 12 due to the action of the hydraulic jack is 2P / 3 at this time, and after stress analysis of the top plate distribution beam 12, it is found that the force acting on the top plate of the double-layer steel truss is 2P / 3.

[0063] (3) as Figure 8 shown, the stress of the hydraulic jack is analyzed, and the bottom plate distribution beam 20 will generate a support force of P / 6, and according to the third law of Newton, it is found that the force acting on the bottom plate of the double-layer steel truss is P / 3. Thus, the distribution of the force loaded on the top plate of the double-layer steel truss and the bottom plate of the double-layer steel truss can be realized.

[0064] (4) as Figure 5 shown, the stress analysis of the top plate distribution beam is carried out, and the upward force is: the upward pressure of the left jack P / 6, the upward pressure of the right jack P / 6, and the reaction force of the top plate of the double-layer steel truss on the top plate distribution beam 12, and the total upward force is P. The external force in the vertical direction is zero, and it is in a balanced state, which conforms to the stress law.

[0065] (5) as Figure 6 shown, the stress analysis of the bottom plate distribution beam 20 is carried out, and the downward force is: the downward pressure of the left jack P / 6, the downward pressure of the right jack P / 6, and the reaction force of the bottom plate of the double-layer steel truss on the bottom plate distribution beam 20, and the external force in the vertical direction is zero, which conforms to the stress law.

[0066] (6) as Figure 7The steel truss is analyzed, and all the downward pressure is equal to P, which is equal to the size of the expected loading force, and meets the loading purpose.

Claims

1. A test apparatus for loading the upper and lower layers of a double-layer steel truss beam, comprising a four-column loading hydraulic press, characterized in that, From top to bottom, it also includes top plate distribution beams, jacks, bottom plate distribution beams, and rigid springs; The top plate distribution beam is horizontally arranged and its middle part is fixedly connected to the lower end of the piston rod of the loading hydraulic press. When in use, the top plate distribution beam presses on the top plate of the double-layer steel truss beam. The top plate distribution beam is used to apply pressure load to the top plate of the double-layer steel truss beam. The bottom plate distribution beam is horizontally arranged directly below the top plate distribution beam. The rigid springs include multiple springs and are connected between the left and right ends of the top plate distribution beam and the bottom plate distribution beam. In use, the bottom plate distribution beam passes through the top and bottom plates of the double-layer steel truss beam and presses down on the bottom plate of the double-layer steel truss beam. The bottom plate distribution beam is used to apply pressure load to the bottom plate of the double-layer steel truss beam. The jacks consist of multiple jacks and are arranged between the top slab distribution beam and the bottom slab distribution beam.

2. The test apparatus for loading the upper and lower layers of a double-layer steel truss beam according to claim 1, characterized in that, The top plate distribution beam has two spaced first loading blocks on its bottom surface, and the bottom plate distribution beam has two spaced second loading blocks on its bottom surface. The distance between the first loading blocks and the second loading blocks is adjustable.

3. The test apparatus for loading the upper and lower layers of a double-layer steel truss beam according to claim 1, characterized in that, The top plate distribution beam and the bottom plate distribution beam are I-beam structures.

4. The test apparatus for loading the upper and lower layers of a double-layer steel truss beam according to claim 1, characterized in that, The top and bottom surfaces of the jack are respectively padded with pressure plates.

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