A rotary wheel type road bridge deck fatigue test device and method

Abstract

The invention discloses a rotating wheel type road bridge deck fatigue test device and method, the device comprises: at least two vertical reaction frames, the vertical reaction frames comprise a pair of columns and a crossbeam, the crossbeam is arranged on the top ends of the columns facing each other and fixedly connected to the two columns; a loading unit arranged on the vertical reaction frames, the loading unit comprises an actuator, a loading crossbeam arranged at the output end of the actuator, a loading vertical beam arranged below the loading crossbeam, a guide seat arranged on the side of the column and a simulated vehicle-mounted component; and a transmission unit arranged on the loading vertical beam, the transmission unit comprises a fixed frame arranged on the loading vertical beam, a driving motor arranged on the fixed frame, a main transmission wheel and a secondary transmission wheel arranged on the fixed frame, a transmission chain arranged on the main transmission wheel and the secondary transmission wheel, and a simulated vehicle-mounted component arranged on the transmission chain, the actuator provides a vertical load for the simulated vehicle-mounted component, the driving motor provides a driving force for the simulated vehicle-mounted component, and the deadweight and reciprocating movement of the vehicle are simulated.

Description

Technical Field

[0001] The present invention belongs to the technical field of road surface loading test, and more specifically, relates to a rotary wheel type road bridge deck fatigue test device and method. Background Art

[0002] The pavement and steel bridge deck components of highways and highway bridges are subjected to the reciprocating wheel pressure of wheel loads during operation. The damage caused by long-term fatigue loads is the main factor causing damage and failure. In actual projects, early damage to pavement or steel bridge decks often occurs, resulting in additional highway and bridge maintenance costs.

[0003] Highway steel bridge decks are three-dimensional load-bearing components composed of multiple steel plates welded or bolted together. They contain many nodes and complex stress distribution. It is often difficult to obtain accurate fatigue resistance indicators through theoretical calculations. Highway pavement is a stacked system composed of multiple layers, multiple types of stone, cement-based materials, and asphalt-based materials. The performance of different paving schemes varies greatly, and new materials and new processes are constantly being applied. It is also difficult for theoretical calculations to give an effective evaluation of highway pavement layers. Due to the complexity of the performance of highway steel bridge decks and pavement layers, it is common to verify their performance through real-scale reciprocating loading tests for important single projects or large-scale and wide-ranging projects.

[0004] For the full-scale test of highway steel bridge decks, the conventional practice is to use a uniaxial fatigue actuator to perform reciprocating loading under a certain constant amplitude fatigue load on one or more points. Since the loading method is very different from the actual vehicle load, this type of test requires preset key areas of concern for design. For areas outside the key areas of concern, there may be large deviations due to the inconsistency between the boundary conditions and the actual situation. Its accuracy is highly dependent on simulation analysis.

[0005] There are two main types of full-scale tests for pavement: real vehicle tests and simulated vehicle tests. In real vehicle tests, the test road surface is laid on a certain circular track, and the wheel pressure is measured by reciprocating loaded vehicles. The effective load is proportional to the vehicle load, which can be exactly the same as the actual working conditions. However, the test cost is very high in terms of site, manpower, and time consumption. Simulated vehicle tests can be carried out indoors or outdoors, using some form of wheel loading equipment (simulated vehicle) to simulate the working conditions of reciprocating wheel pressure. The main difficulty lies in how to increase the effective load of the wheel while maintaining a sufficient loading frequency. Summary of the invention

[0006] In view of the above defects or improvement needs of the prior art, the present invention provides a rotary wheel type road bridge deck fatigue test device and method, which provides a vertical load to the simulated vehicle-mounted component through an actuator to simulate the dead weight of the vehicle, and provides a driving force to the simulated vehicle-mounted component through a transmission unit, so that the simulated vehicle moves on the test piece, thereby realizing an effective loading test on the road surface or bridge deck structure. In addition, during the loading test, no manual participation is required, and the device automatically adjusts the parameters according to the requirements of different environments, thereby increasing the effective loading force on the test piece without increasing the dead weight of the simulated vehicle, taking into account the requirements of increasing the effective load and maintaining the loading frequency, and realizing an accelerated fatigue damage test of the road pavement or steel bridge deck.

[0007] In order to solve the above problems, according to a first aspect of an embodiment of the present invention, a rotary wheel type road bridge deck fatigue test device is provided, comprising:

[0008] At least two vertical reaction frames, each vertical reaction frame includes a pair of columns and a crossbeam, the crossbeam is mounted on the opposite sides of the top ends of the columns and is fixedly connected between the two columns;

[0009] A loading unit disposed on the vertical reaction frame, the loading unit comprising an actuator, a loading beam disposed at an output end of the actuator, a loading vertical beam disposed below the loading beam, and a guide seat disposed on a side of the column;

[0010] And a transmission unit arranged on the loading vertical beam, the transmission unit includes a fixed frame arranged on the loading vertical beam, a drive motor arranged on the fixed frame, a main drive wheel and an auxiliary drive wheel arranged on the fixed frame, a transmission chain arranged on the main drive wheel and the auxiliary drive wheel, and a simulated vehicle-mounted component arranged on the transmission chain, the actuator is used to provide a vertical load for the simulated vehicle-mounted component, and the drive motor provides a driving force for the simulated vehicle-mounted component to simulate the vehicle's own weight and reciprocating movement.

[0011] Furthermore, the fixing frames are provided in a group at each end of the loading vertical beam, and the two groups of fixing frames are arranged opposite to each other;

[0012] The driving motor is arranged on the side of one set of fixing frames;

[0013] The main transmission wheel is arranged on a fixing frame on which one end of the driving motor is installed;

[0014] The auxiliary transmission wheel is arranged on a fixing frame at one end where the driving motor is not installed.

[0015] Furthermore, the transmission unit also includes an adjusting gear;

[0016] The adjusting gear is respectively arranged at one end of the loading vertical beam and is rotatably connected between the two loading vertical beams through a rotating shaft. The adjusting gears at both ends are respectively meshed with the main transmission wheel and the auxiliary transmission wheel.

[0017] Furthermore, the main transmission wheel, the auxiliary transmission wheel and the adjustment gear are two identical gears arranged concentrically and at intervals, connected as a whole and rotating synchronously;

[0018] The transmission chain is two identical chains arranged in parallel and at intervals, connected as a whole and rotating synchronously, and arranged on the main transmission wheel and the auxiliary transmission wheel to mesh with them;

[0019] The bottom of the transmission chain is also meshed with the adjusting gears at both ends.

[0020] Furthermore, the simulated vehicle-mounted component is provided with multiple components that are equidistantly spaced on the outer ring of the transmission chain, including a vehicle body fixed on the transmission chain, an axle provided on the vehicle body, a loading wheel provided in the middle of the axle, and guide wheels provided at both ends of the axle.

[0021] Furthermore, the vehicle bodies are multiple, and are arranged at equal intervals on the outer ring of the transmission chain, and the two ends are respectively fixed to the same position of the two chains of the transmission chain, and are connected by a wheel axle;

[0022] The two ends of the wheel axle respectively pass through the vehicle body and extend outwards;

[0023] The loading wheel is rotatably mounted at the middle position of the wheel shaft and is arranged between the two chains of the transmission chain;

[0024] The guide wheels are arranged at the extensions of both ends of the wheel axle and are matched with the loading track.

[0025] Furthermore, two mounting seats are provided at corresponding positions of the loading crossbeam and the crossbeam;

[0026] A pin is arranged on the mounting seat, the mounting seat on the crossbeam is rotationally connected to the fixed end of the actuator, and the mounting seat on the loading crossbeam is rotationally connected to the actuator.

[0027] Furthermore, the loading vertical beams are used in pairs, parallel and spanning between the multiple loading horizontal beams, and are fixedly connected to the multiple loading horizontal beams;

[0028] A loading track is also provided at the bottom of each loading vertical beam along the length direction, and the loading track is a straight track.

[0029] The loading track is a straight track with a protrusion at the bottom.

[0030] Furthermore, the guide seats are provided in a group on each side of the two columns of each vertical reaction frame facing each other, and each group of guide seats includes two limit plates arranged opposite to each other;

[0031] The limit plate is fixed on the column in the vertical direction, and a gap is left between the two limit plates as a guide channel;

[0032] The width of the guide channel is the same as that of the loading beam. Both ends of the loading beam are arranged in the guide channels on the columns on both sides, and the loading beam moves in the guide channel along the vertical direction.

[0033] According to a second aspect of an embodiment of the present invention, a fatigue test method for a rotary wheel type road bridge deck is provided, comprising:

[0034] S100. Install the test specimens for the simulation test at the experimental site, arrange effective temporary supports, install the experimental device on the temporary supports, and remove the temporary supports after the installation is completed;

[0035] S200. According to the preset fatigue test requirements, the functions of the experimental device are tested separately and linked to ensure the normal use of the device;

[0036] S300, starting the device in the order of increasing the ambient temperature, applying an additional load to the actuator, and driving the simulated vehicle-mounted components, and starting the experiment;

[0037] S400: During the experiment, if a short period of observation is required or the monitoring personnel temporarily leave, all actions of the experimental device shall be suspended;

[0038] S500: After the experiment is completed, the device is stopped in the order of driving the simulated vehicle-mounted component to decelerate and stop, the actuator is unloaded, and the environment is cooled down, and the test is terminated.

[0039] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art: BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is a schematic structural diagram of a rotary wheel type road bridge deck fatigue testing device according to an embodiment of the present invention;

[0041] Figure 2 This is a schematic diagram of the vertical reaction frame structure of a rotary wheel type road and bridge deck fatigue testing device according to an embodiment of the present invention;

[0042] Figure 3 This is a schematic diagram of the structure of a loading unit of a rotary wheel type road and bridge deck fatigue testing device according to an embodiment of the present invention;

[0043] Figure 4 This is a schematic diagram of the actuator connection of a rotary wheel type road and bridge deck fatigue testing device according to an embodiment of the present invention;

[0044] Figure 5 This is a schematic diagram of the structure of a transmission unit of a rotary wheel type road and bridge deck fatigue testing device according to an embodiment of the present invention;

[0045] Figure 6 This is a schematic diagram of the internal structure of a transmission unit of a rotary wheel type road and bridge deck fatigue testing device according to an embodiment of the present invention;

[0046] Figure 7 This is a schematic diagram of the structure of a simulated vehicle-mounted component of a rotary wheel type road and bridge deck fatigue test device according to an embodiment of the present invention;

[0047] Figure 8 A schematic diagram of a process flow of a rotating wheel type road bridge deck fatigue test method according to an embodiment of the present invention;

[0048] Fig. 9 This is a schematic diagram of a specific flow of step S200 in a rotary wheel type road bridge deck fatigue test method according to an embodiment of the present invention;

[0049] Fig.10 This is a specific flow chart of step S300 in a rotary wheel type road bridge deck fatigue test method according to an embodiment of the present invention;

[0050] Fig.11 Schematic diagram of a specific flow chart of step S500 in a rotating wheel type road bridge deck fatigue test method according to an embodiment of the present invention.

[0051] In all the drawings, the same figure numbers represent the same technical features, specifically: 1-vertical reaction frame, 11-column, 12-crossbeam, 2-loading unit, 21-actuator, 22-loading crossbeam, 23-loading vertical beam, 24-guide seat, 25-loading track, 3-transmission unit, 31-fixed frame, 32-drive motor, 33-main drive wheel, 34-auxiliary drive wheel, 35-adjusting gear, 36-transmission chain, 37-simulated vehicle-mounted components, 371-vehicle body, 372-axle, 373-loading wheel, 374-guide wheel, 38-unloaded track. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0053] Example 1

[0054] like Figure 1As shown, an embodiment of the present invention provides a rotary wheel type road bridge deck fatigue test device, comprising: a vertical reaction frame 1, a loading unit 2 and a transmission unit 3 arranged between the vertical reaction frames 1. The loading unit 2 comprises an actuator 21, and a simulated vehicle-mounted component 37 is provided on the transmission unit 3. The actuator 21 provides a vertical load to the simulated vehicle-mounted component 37 to simulate the dead weight of the vehicle, and the transmission unit 3 provides a horizontal force to the simulated vehicle-mounted component 37, so that the simulated vehicle moves back and forth on the specimen, thereby realizing an effective loading test on the road surface or bridge deck structure. In addition, during the loading test, no manual participation is required, and the device automatically adjusts the parameters according to the requirements of different environments, thereby increasing the effective loading force on the specimen without increasing the dead weight of the simulated vehicle, taking into account the requirements of increasing the effective load and maintaining the loading frequency, thereby realizing an accelerated fatigue damage test on the road pavement or steel bridge deck.

[0055] like Figure 2 As shown, at least two vertical reaction frames 1 are provided, which are equidistantly arranged on the specimen along the length direction, and each vertical reaction frame 1 includes a pair of columns 11 and a crossbeam 12. The column feet of the columns 11 are connected to the specimen by tensile anchor bolts, and the crossbeam is arranged on the side facing the top of the column 11 and fixedly connected to the two columns 11. The columns 11 and the crossbeam 12 are made of steel not lower than Q345, and their surfaces are coated with anti-corrosion materials.

[0056] Preferably, a fixed reaction floor or equipment pedestal is provided on the specimen, and the column foot of the column 11 is connected to the reaction floor or equipment pedestal through a tensile anchor bolt.

[0057] At least two actuators 21 are provided at the bottom of each cross beam 12 , symmetrically mounted at both ends of the cross beam 12 , and are hydraulic devices or servo motor devices. The maximum load of a single actuator 21 is not less than 500KN.

[0058] like Figure 3 , 4As shown, the loading unit 2 also includes a loading crossbeam 22 disposed at the output end of the actuator 21, a loading vertical beam 23 disposed below the loading crossbeam 22, and a guide seat 24 disposed on the side of the column 11. Among them, two mounting seats are provided at the corresponding positions of the loading crossbeam 22 and the crossbeam 12, and the mounting seats are provided with pins. The mounting seats on the crossbeam 12 are rotationally connected to the fixed end of the actuator 21, and the mounting seats on the loading crossbeam 22 are rotationally connected to the actuator 21. When non-vertical force appears on the loading crossbeam 22, the mounting seats at both ends of the actuator 21 rotate to eliminate the horizontal force, so that the force output on the loading crossbeam 22 is a stable vertical force. The loading vertical beams 23 are used in pairs, parallel and spanning between multiple loading crossbeams 22, and are fixedly connected to multiple loading crossbeams 22. The bottom of each loading vertical beam 23 is also provided with a loading track 25 along the length direction. The loading track 25 is a straight track with a protrusion at the bottom. It is made of steel material not lower than Q345, and the surface is polished and coated with anti-corrosion paint to prevent it from bending when subjected to force and affecting the experimental effect. The guide seat 24 is provided on each side of the two columns 11 facing each other of each vertical reaction frame 1. Each group of guide seats 24 includes two opposite limit plates, which are fixed on the columns 11 in the vertical direction. A gap is left between the two limit plates as a guide channel. The width of the guide channel is the same as that of the loading cross beam 22. The two ends of the loading cross beam 22 are provided in the guide channels on the columns 11 on both sides, and it moves in the vertical direction in the guide channel.

[0059] like Figure 5 , 6As shown, both ends of the loading vertical beam 23 are extended to exceed the range of the vertical reaction frames 1 at both ends, and both ends are provided with inclined surfaces so that the loading vertical beam 23 is arranged as a trapezoid as a whole, and the short bottom of the trapezoid is located at the bottom. The transmission unit 3 includes a fixed frame 31 arranged on the loading vertical beam 23, a driving motor 32 arranged on the fixed frame 31, a main transmission wheel 33 and a secondary transmission wheel 34 arranged on the fixed frame 31, and an adjustment gear 35 arranged on the loading vertical beam 23. Among them, the fixed frame 31 is provided with a group at each end of the loading vertical beam 23, and the two groups of fixed frames 31 on the same transmission unit 3 are arranged opposite to each other, and each group of fixed frames 31 includes a pair of support plates, and the support plates are provided with one each on the loading vertical beam 23, and the support plates are provided with mounting holes. The driving motor 32 is a variable frequency motor that can rotate forward and reverse, and is arranged on the side of a support plate of one of the fixed frames 31. A reducer is also arranged between the driving motor 32 and the support plate. The output end cover of the reducer is fixed to the support plate and is arranged concentrically with the mounting hole on the support plate. The input shaft is connected to the output shaft of the driving motor 32. The main transmission wheel 33 is arranged on the fixed frame 31 where one end of the driving motor 32 is installed. It is connected between the two support plates through a transmission shaft and rotates on the fixed frame 31. The transmission shaft is rotatably connected to the mounting hole of the support plate through a bearing, and one end is connected to the output shaft of the reducer. The auxiliary transmission wheel 34 is arranged on the fixed frame 31 where the driving motor 32 is not installed. It is connected between the two support plates through a transmission shaft and rotates on the fixed frame 31. The transmission shaft is rotatably connected to the mounting hole of the support plate through a bearing. The adjusting gear 35 is provided at one end of each loading vertical beam 23 and is rotatably connected between the two loading vertical beams 23 via a rotating shaft. The adjusting gears 35 at both ends are respectively meshed with the main transmission wheel 33 and the auxiliary transmission wheel 34 .

[0060] The main transmission wheel 33, the auxiliary transmission wheel 34 and the adjustment gear 35 are two identical gears arranged concentrically and at intervals, connected as a whole and rotating synchronously.

[0061] The transmission unit 3 further includes a transmission chain 36, which is two identical chains arranged in parallel and spaced apart, connected as a whole and rotated synchronously, and is arranged on the main transmission wheel 33 and the auxiliary transmission wheel 34 to mesh with them, and the bottom of the transmission chain 36 is also meshed with the adjustment gears 35 at both ends. When the driving motor 32 is started, the transmission chain 36 is driven to rotate through the main transmission wheel 33, at which time the auxiliary transmission wheel 34 and the main transmission wheel 33 control the length of the transmission chain 36 along the moving direction, and the adjustment gear 35 controls the distance between the transmission chain 36 and the loading track 25, so as to prevent the transmission chain 36 from contacting with the loading track 25 or the loading vertical beam 23, thereby affecting its rotation performance.

[0062] like Figure 7As shown, the transmission chain 36 is provided with a simulated vehicle-mounted component 37, and the simulated vehicle-mounted component 37 is provided with multiple components, which are equidistantly arranged on the outer ring of the transmission chain 36, including a vehicle body 371 fixed on the transmission chain 36, a wheel axle 372 arranged on the vehicle body 371, a loading wheel 373 arranged in the middle of the wheel axle 372, and guide wheels 374 arranged at both ends of the wheel axle 372. Among them, the vehicle body 371 is multiple, which is equidistantly arranged on the outer ring of the transmission chain 36, and the two ends are respectively fixed to the same position of the two chains of the transmission chain 36, and are connected by the wheel axle 372, and the two ends of the wheel axle 372 respectively pass through the vehicle body 371 and extend outwards. The loading wheel 373 is rotatably mounted at the middle position of the wheel axle 372 and is disposed between the two chains of the transmission chain 36. The guide wheel 374 is disposed at the extension of both ends of the wheel axle 372, and a groove is provided on its surface along the circumferential direction. The width of the groove is the same as the protrusion of the loading track 25, and the two form a fit.

[0063] The transmission unit 3 further includes an idle track 38, which is arranged along the periphery of the transmission chain 36, and wraps the simulated vehicle-mounted component 37 that is not in contact with the test piece, and completely shields the simulated vehicle-mounted component 37. The bottom surface of the loading wheel 373 in the idle track 38 is in contact, providing guidance for the simulated vehicle-mounted component 37, and at the same time providing protection for the transmission unit 3 to prevent external debris from falling into it and causing damage.

[0064] Preferably, when the transmission chain 36 rotates, it drives the simulated vehicle-mounted component 37 thereon to rotate, and the loading wheel 373 at the bottom thereof contacts the surface of the specimen, provides a downward load, and rotates on the surface of the specimen. After completing the test, a single loading wheel 373 moves to the unloaded track 38, and then rotates to the loading track 25 for the next cycle, thereby realizing a cyclic wheel pressure test. When a wheel pressure test of reverse driving is required, it is realized by reversing the drive motor 32; when a test of simulating different driving speeds is required, it is realized by adjusting the frequency of the drive motor 32.

[0065] Preferably, the loading wheel 373 is a pneumatic tire, a solid rubber tire or a steel plate reinforced solid rubber tire, and the pressure between the loading wheel 373 and the sample is maintained between 0.7 MPa and 5 MPa.

[0066] Preferably, bearings are provided at the connection positions of the loading wheel 373 and the guide wheel 374 to reduce the wear of the wheel shaft 372 or the pin shaft.

[0067] This experimental device also includes an environmental loading system, which is used to perform environmental loading on the pavement during the accelerated fatigue test, including a frame, enclosure, heating fan, thermal sensor, control system and alarm device. Among them, the frame is made of angle steel or square steel material not lower than Q235, and the exterior is coated with anti-corrosion material, and the frame is also provided with structures of other equipment. The enclosure is a transparent polymer film, which is connected between the frame and the indoor floor, and the connection is a sealed connection to prevent contact with the outside air. The heating fan is arranged on the frame, and its air outlet is aligned with the position of the pavement specimen, and the heating fan is provided with multiple ones to ensure the uniform and stable temperature in the experimental area, and the temperature of the experiment is controlled between 55-65°C. The thermal sensor is a thermocouple sensor, which is arranged in the pavement specimen, and is used to detect the temperature of the pavement during the test, and to adjust the power of the hot fan with feedback information. The warning device is an audible and visual alarm device, which is also connected to a display screen, and its signal input end is also connected to a temperature sensor. The temperature sensor is arranged in an experimental environment surrounded by a frame, and an alarm is sounded when the air and steel structure surface temperature in the experimental environment are higher than 40°C, thereby preventing operators from being scalded during operation.

[0068] Preferably, since the surface of the road pavement or steel bridge deck is inevitably uneven, there is a certain load unevenness when the simulated vehicle-mounted unit walks on the surface of the specimen. A force sensor is also provided at the output end of the actuator 21, and a strain sensor is embedded in the specimen. The load output by the actuator 21 is adjusted by the imbalance information monitored by the force sensor and the strain sensor. At the same time, during the experiment, the load output by the actuator 21 is changed to simulate vehicles with different dead weights.

[0069] Preferably, in the fatigue test of steel bridge deck, the maximum single wheel load is 200kN, the equivalent frequency is 0.13Hz, and the working day is 12 hours, so 2 million effective loadings can be completed within 90 days; in the accelerated fatigue test of pavement, the maximum single wheel load is 200kN, the equivalent frequency is 0.54Hz, and the working day is 12 hours, so 10 million effective loadings can be completed within 220 days.

[0070] Example 2

[0071] like Figure 8 As shown, an embodiment of the present invention provides a fatigue test method for a rotary wheel type road bridge deck, comprising the following steps:

[0072] S100. Install the test specimens for the simulation test at the experimental site, arrange effective temporary supports, install the experimental device on the temporary supports, and remove the temporary supports after the installation is completed;

[0073] S200. According to the preset fatigue test requirements, the functions of the experimental device are tested separately and linked to ensure the normal use of the device;

[0074] S300, starting the device in the order of increasing the ambient temperature, applying an additional load to the actuator 21, and driving the simulated vehicle-mounted component 37, and starting the experiment;

[0075] S400: During the experiment, if a short period of observation is required or the monitoring personnel temporarily leave, all actions of the experimental device shall be suspended;

[0076] S500, after the experiment is completed, the device is stopped in the order of driving the simulated vehicle-mounted component 37 to decelerate and stop, the actuator 21 to unload, and the environment to cool down, and the test is terminated.

[0077] like Fig. 9 As shown, step S200 is specifically as follows:

[0078] S201, disabling the loading and environmental loading functions of the actuator 21, gradually increasing the speed of the simulated vehicle-mounted component 37 from slow to fast, until the simulated vehicle-mounted component 37 reaches the designed loading speed and completes no less than ten cycles of rotation along the entire length of the loading track 37, and visually and sensor data are used to check the drive to ensure stable operation without abnormal noise or vibration;

[0079] S202, do not enable the environmental loading function, move the simulated vehicle-mounted component 37 to the middle span, 1 / 4 span, 3 / 4 span and two end points of the loading beam 22 in sequence, gradually increase the pressure of the actuator 21 until the test load is reached, and verify the loading system through sensor data to ensure stable operation, no unbalanced load, and no sensor failure;

[0080] S203. When conducting accelerated fatigue test on pavement, check the effect of environmental loading system, do not enable reciprocating unit 3 and actuator 21, apply hot air to the specimen at set temperature until the temperature reaches 60°C, and check the joints between enclosure, frame and ground to ensure there is no air leakage.

[0081] like Fig.10 As shown, step S300 is specifically as follows:

[0082] S301. Raise the ambient temperature to 60°C and stabilize it for 30 minutes, ensuring that the ambient temperature fluctuation does not exceed ±5°C during this period;

[0083] S302, synchronously increase the thrust of the actuator 21 at a speed not exceeding 50 kN / min until the designed test load is reached, and hold the load for 15 minutes;

[0084] S303, start the drive motor 32 to drive the simulated vehicle-mounted component 37 to perform a rotary motion, increase the speed of the drive motor 32 from slow to fast until the test design speed is reached, and record the test process.

[0085] Step S400 specifically includes:

[0086] S401, when a short pause is required for observation during the test, only the speed of the simulated vehicle-mounted component 37 is reduced to 0, and the actuator and environmental load should be kept unchanged at this time;

[0087] S402. When the on-duty personnel need to leave during the test, a long pause process is executed, and the operation is performed in the order of simulating the vehicle-mounted component 37 to slow down and stop, and the actuator 21 to unload.

[0088] In step S402, if the accelerated fatigue failure test of the road pavement is carried out, the ambient temperature should be kept constant to avoid the influence of temperature stress.

[0089] like Fig.11 As shown, step S500 is specifically as follows:

[0090] S501, controlling the driving motor 32 to decelerate until the speed of the simulated vehicle-mounted component 37 is reduced to 0;

[0091] S502, unloading the actuator 21 synchronously at a speed not exceeding 50 kN / min until the loading track 25 and the simulated vehicle-mounted component 37 are emptied;

[0092] S503, stop heating, wait for the ambient temperature to drop to room temperature or accelerate the cooling process by using a ventilation fan.

[0093] During the experiment, the normal operation and safety of the experiment must be maintained and the following standards must be implemented:

[0094] a. When the simulated vehicle-mounted component 37 is in a non-stationary state, it is not allowed to approach or touch the test device;

[0095] b. When the warning device of the environmental loading system lights up, it is not allowed to enter the enclosure;

[0096] c. When the simulated vehicle-mounted component 37 is in a stationary state but the actuator 21 is not unloaded, it is allowed to observe the specimen at a safe distance, but there should be no behavior that disturbs the actuator 21, the loading beam 22, or the specimen.

[0097] d. During the wheel pressure acceleration test, at least one person should be on duty to monitor the sensor and equipment feedback readings of the test process. When it is necessary to get close to the test system for observation during the test, at least two people should be on duty, and at least one of them should remain at a safe distance.

[0098] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A rotary wheel type road bridge deck fatigue test device, characterized in that: include: At least two vertical reaction frames (1), each vertical reaction frame (1) comprising a pair of upright posts (11) and a crossbeam (12), wherein the crossbeam is mounted on the opposite sides of the top ends of the upright posts (11) and is fixedly connected to the two upright posts (11); A loading unit (2) disposed on the vertical reaction frame (1), the loading unit (2) comprising an actuator (21), a loading beam (22) disposed at an output end of the actuator (21), a loading vertical beam (23) disposed below the loading beam (22), and a guide seat (24) disposed on a side of the column (11); and a transmission unit (3) arranged on the loading vertical beam (23), the transmission unit (3) comprising a fixing frame (31) arranged on the loading vertical beam (23), a driving motor (32) arranged on the fixing frame (31), a main transmission wheel (33) and a secondary transmission wheel (34) arranged on the fixing frame (31), a transmission chain (36) arranged on the main transmission wheel (33) and the secondary transmission wheel (34), and a simulated vehicle-mounted component (37) arranged on the transmission chain (36), wherein a vertical load is provided to the simulated vehicle-mounted component (37) through the actuator (21), and the driving motor (32) provides a driving force to the simulated vehicle-mounted component (37) to simulate the deadweight and reciprocating movement of the vehicle; a set of the fixing frames (31) is provided at each end of the loading vertical beam (23), and the two sets of fixing frames (31) are arranged opposite to each other; The driving motor (32) is arranged on the side of one set of fixing frames (31); The main transmission wheel (33) is arranged on a fixing frame (31) on which one end of the driving motor (32) is installed; The auxiliary transmission wheel (34) is arranged on the fixing frame (31) at the end where the driving motor (32) is not installed; The simulated vehicle-mounted component (37) comprises a vehicle body (371) fixed on the transmission chain (36), a wheel axle (372) disposed on the vehicle body (371), a loading wheel (373) disposed in the middle of the wheel axle (372), and guide wheels (374) disposed at both ends of the wheel axle (372); The vehicle bodies (371) are multiple and are arranged at equal intervals on the outer ring of the transmission chain (36), with two ends respectively fixed to the same position of two chains of the transmission chain (36) and connected via a wheel axle (372); Both ends of the wheel axle (372) respectively pass through the vehicle body (371) and then extend outwards; The loading wheel (373) is rotatably mounted at a middle position of the wheel shaft (372) and is disposed between two chains of the transmission chain (36); The guide wheels (374) are arranged at the extensions of both ends of the wheel axle (372) and are matched with the loading track (25).

2. A rotary wheel type road bridge deck fatigue test device according to claim 1, characterized in that: The transmission unit (3) further comprises an adjusting gear (35); The adjusting gear (35) is provided at one end of each loading vertical beam (23), and is rotatably connected between the two loading vertical beams (23) via a rotating shaft. The adjusting gears (35) at both ends are respectively meshed with the main transmission wheel (33) and the auxiliary transmission wheel (34).

3. A rotary wheel type road bridge deck fatigue test device according to claim 2, characterized in that: The main transmission wheel (33), the auxiliary transmission wheel (34) and the adjustment gear (35) are two identical gears arranged concentrically and at intervals, connected as a whole and rotating synchronously; The transmission chain (36) is two identical chains arranged in parallel and at intervals, connected as a whole and rotating synchronously, and arranged on the main transmission wheel (33) and the auxiliary transmission wheel (34) to mesh with them; The bottom of the transmission chain (36) is also meshed with the adjustment gears (35) at both ends.

4. A rotary wheel type road bridge deck fatigue test device according to any one of claims 1 to 3, characterized in that: Two mounting seats are provided at corresponding positions of the loading crossbeam (22) and the crossbeam (12); A pin is provided on the mounting seat, the mounting seat on the crossbeam (12) is rotationally connected to the fixed end of the actuator (21), and the mounting seat on the loading crossbeam (22) is rotationally connected to the actuator (21).

5. The rotary wheel type road bridge deck fatigue test device according to claim 4, characterized in that: The loading vertical beams (23) are used in pairs, and are parallel and span between the multiple loading horizontal beams (22), and are fixedly connected to the multiple loading horizontal beams (22); A loading track (25) is also provided at the bottom of each loading vertical beam (23) along the length direction, and the loading track (25) is a straight track; The loading track (25) is a straight track, and a protrusion is provided at the bottom thereof.

6. The rotary wheel type road bridge deck fatigue test device according to claim 5, characterized in that: The guide seats (24) are provided in a group on each side of the two upright posts (11) of each vertical reaction frame (1) facing each other, and each group of guide seats (24) includes two limit plates arranged opposite to each other; The limit plate is fixed on the column (11) in the vertical direction, and a gap is left between the two limit plates as a guide channel; The width of the guide channel is the same as that of the loading crossbeam (22); both ends of the loading crossbeam (22) are arranged in the guide channels on the two side columns (11), and the loading crossbeam moves in the vertical direction in the guide channels.

7. A rotating wheel type road bridge deck fatigue test method, implemented by using a rotating wheel type road bridge deck fatigue test device as described in any one of claims 1 to 6, characterized in that: include: S100. Install the test specimens for the simulation test at the experimental site, arrange effective temporary supports, install the experimental device on the temporary supports, and remove the temporary supports after the installation is completed; S200. According to the preset fatigue test requirements, the functions of the experimental device are tested separately and linked to ensure the normal use of the device; S300, starting the device in the order of increasing the ambient temperature, applying an additional load to the actuator (21), and driving the simulated vehicle-mounted component (37), and starting the experiment; S400: During the experiment, if a short period of observation is required or the monitoring personnel temporarily leave, all actions of the experimental device shall be suspended; S500, after the experiment is completed, the device is stopped in the order of decelerating and stopping the driving simulation vehicle-mounted component (37), unloading the actuator (21), and cooling the environment, thereby terminating the test.

Images