Road pavement fatigue-abrasion-damp heat wheel pressure type testing device and method

Abstract

The invention discloses a road pavement fatigue-abrasion-damp heat wheel pressure type test device and method, and the device comprises a loading unit which comprises an actuator, a simulation vehicle-mounted assembly, and a loading track; the simulation vehicle-mounted assembly comprises a vehicle body, a wheel axle arranged at the bottom of the vehicle body, a loading wheel arranged on the wheel axle, a guide wheel arranged at the top of the vehicle body and auxiliary wheels arranged on the two sides of the vehicle body. The environment loading system comprises a frame, an enclosure, a heating module, a humidifying module and a warning device; the resistance simulation unit is used for providing torque resistance for the simulation vehicle-mounted assembly; the position, in the middle of the loading track, of the simulation vehicle-mounted assembly serves as the initial position, and the position, from the simulation vehicle-mounted assembly to one end of the loading track, of the simulation vehicle-mounted assembly serves as the maximum displacement position. A real operation scene is simulated, the influence of various different adverse factors on the comprehensive performance of the test piece is comprehensively considered, and the reliability of a test result is enhanced.

Description

Technical Field

[0001] The present invention belongs to the technical field of pavement loading tests, and more specifically, relates to a pavement paving fatigue-wear-humidity and heat wheel pressure test device and method. Background Art

[0002] The pavement of highways and highway bridges is subjected to the reciprocating rolling of the loading wheel and the friction applied during the acceleration / braking process of the vehicle during operation. In long-term operation, cracking, bulging, rutting, internal interface slippage, surface anti-slip wear failure and other defects may occur. Since highway pavement is a stacked system composed of multiple layers, multiple stones, 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 difficult to give an effective evaluation of the highway pavement layer through theoretical calculations, and the performance of the pavement layer must be tested by experimental methods. Various indicators that affect the performance of pavement, such as fatigue resistance, moisture and heat resistance, and wear resistance, can be evaluated individually through small specimen tests, which can save test costs, but there is a lack of intuitive reflection of the coupling effect between different types of defects, and there is still a certain need to carry out real-scale tests.

[0003] The loading wheel of conventional wheel pressure test equipment is a driven wheel, which mainly reflects the effect of fatigue-humidity and heat on the road pavement. It cannot achieve accelerated loading for the road pavement wear problem. The present invention proposes a road pavement fatigue-wear-humidity and heat wheel pressure test device and method, which can perform cyclic wheel pressure on a full-scale road pavement specimen to comprehensively reflect the effective life of the road pavement under the action of fatigue load, wear and environmental factors. Summary of the invention

[0004] In view of the above defects or improvement needs of the prior art, the present invention provides a road pavement fatigue-wear-humidity and heat wheel pressure test device and method, which provides a vertical load for the simulated vehicle-mounted component through an actuator, provides a driving force for the simulated vehicle-mounted component through a reciprocating motion unit, and simulates the increased friction force of the vehicle braking on the loaded wheel and the specimen surface through a resistance simulation unit, so as to simulate various loads during vehicle driving.

[0005] To achieve the above objectives, according to a first aspect of an embodiment of the present invention, a road pavement fatigue-wear-humidity wheel pressure test device is provided, comprising:

[0006] A loading unit, the loading unit comprising an actuator, a simulated vehicle-mounted component and a loading track; the simulated vehicle-mounted component comprising a vehicle body, an axle arranged at the bottom of the vehicle body, a loading wheel arranged on the axle, a guide wheel arranged at the top of the vehicle body and auxiliary wheels arranged at both sides of the vehicle body;

[0007] An environmental loading system, the environmental loading system comprising a frame, enclosure, a heating module, a humidification module and an alarm device;

[0008] a resistance simulation unit, the resistance simulation unit being used to provide torque resistance for simulating a vehicle-mounted component;

[0009] The position of the simulated vehicle-mounted component in the middle of the loading track is taken as the starting position, and the position to one end of the loading track is taken as the maximum displacement position.

[0010] Further, the resistance simulation unit includes a clockwork spring and a ratchet;

[0011] One end of the spring is connected to the loading wheel, and the other end is connected to the ratchet, which is arranged on the vehicle body. When the simulated vehicle-mounted component is in the starting position, the spring is in the original length state, and the ratchet is in the relaxed state;

[0012] During the process of the simulated vehicle-mounted component moving from the starting position to the maximum displacement position, the ratchet wheel is tightened and the spring is stretched to generate tensioning elastic force, resulting in increasing torque resistance of the loading wheel;

[0013] During the process of the simulated vehicle-mounted component moving from the maximum displacement position to the starting position, the ratchet wheel is loosened and the spring is quickly released, and no additional torque resistance is applied to the loading wheel.

[0014] Further, the resistance simulation unit includes a brake structure;

[0015] The brake structure adopts servo control, and a brake pad is arranged inside the brake structure, and the brake pad is arranged on the outer periphery of the wheel axle;

[0016] When the simulated vehicle-mounted component is in the starting position, the brake structure is in a relaxed state;

[0017] During the process of the simulated vehicle-mounted component moving from the starting position to the maximum displacement position, the brake pads are closed and a constant braking torsional resistance is applied to the loading wheel; during the process of the simulated vehicle-mounted component moving from the maximum displacement position to the starting position, the brake pads are released and no additional torque resistance is applied to the loading wheel.

[0018] Further, the resistance simulation unit includes a damper;

[0019] The damper is an eddy current damper, which provides a stable torque by energizing the electromagnet to provide resistance for the loading wheel;

[0020] When the simulated vehicle-mounted component is in the starting position, the damper is in a power-off state;

[0021] During the process of the simulated vehicle-mounted component moving from the starting position to the maximum displacement position, the damper is energized to apply a constant damping torque to the loading wheel;

[0022] During the process of the simulated vehicle-mounted component moving from the maximum displacement position to the starting position, the damper is powered off and no additional torque is applied to the loading wheel.

[0023] Further, the heating module includes a heating fan and a thermal sensor;

[0024] The humidification module is used to periodically replenish the moisture on the surface of the road and bridge deck pavement specimen, and is a nozzle array composed of multiple nozzles.

[0025] Further, a monitoring system is included;

[0026] The monitoring system includes a sensor assembly, a three-dimensional laser scanner, an infrared camera and a fiber optic sensor.

[0027] Further, the sensor assembly is arranged in the simulated vehicle-mounted assembly and the environmental loading system, and includes a force sensor, a displacement sensor, an acceleration sensor, a temperature sensor and a humidity sensor;

[0028] The three-dimensional laser scanner is used to detect the degradation of the flatness of the test piece, which degradation includes rutting, bulging and displacement;

[0029] The infrared camera is used to detect cracks and water seepage on the surface of the test piece;

[0030] The optical fiber sensor is arranged into a multi-layer orthogonal network and embedded in the test piece to measure the relative slip of different layers of the test piece.

[0031] Further, it also includes a control system;

[0032] The control system is used to control the operation of the loading unit, the environmental loading system, the resistance simulation unit and the monitoring system.

[0033] Furthermore, the actuator applies vertical pressure to the loading track, simulating the contact between the top of the vehicle-mounted component and the loading track, and transmits the vertical pressure to the road and bridge deck pavement specimen, applying an effective pressure exceeding the deadweight of the loading vehicle in the vertical downward direction, so that the specimen accumulates vertical compression fatigue damage;

[0034] When the loading vehicle body moves from the starting position to the maximum displacement position, the resistance simulation unit applies additional torque resistance to the loading wheel, increasing the static friction between it and the road and bridge pavement, causing the specimen to accumulate horizontal shear fatigue damage and surface wear damage.

[0035] According to a second aspect of an embodiment of the present invention, there is provided a road pavement fatigue-wear-humidity wheel pressure test method, comprising the following steps:

[0036] T100. Determine the test parameters and the number of test cycles through theoretical analysis and sample tests. The test process is managed on a daily basis.

[0037] T200. Before starting the test every day, check the pavement temperature, adjust the output power of the heating module to ensure that the surface temperature of the specimen reaches between 55-65°C, and spray water on the specimen surface through the humidification module until the surface of the test section of the specimen is completely wet;

[0038] T300, start the device to conduct durability test on the surface of the test piece;

[0039] T400, after completing one cycle of loading, the fiber optic sensor samples at a frequency of 50Hz, and performs additional cycles of loading under the test load. The fiber optic sensor data is interpolated to generate strain cloud maps of the bridge pavement at different depths, and the slip between each layer is calculated;

[0040] T500. After resetting the simulated vehicle-mounted component to the starting point, stop the operation of the device, photograph the surface of the specimen with an infrared camera at a fixed point, record the water seepage on the surface of the specimen in the test section, collect the flatness change of the specimen at a fixed point with laser scanning, and record the data according to the loading date;

[0041] T600. After completing a cycle of testing, check that all equipment is in normal condition, ensure that the heating module continues to work, and that the rest of the equipment is powered off;

[0042] T700, check the data recorded by sensors in the simulated vehicle components and environmental loading system of the test on the day. If the relative value of the data to the test plan exceeds 10%, repair the device and conduct subsequent tests after eliminating the problem;

[0043] T800, every ten cycles of testing, check and evaluate the tire wear of the loading wheel and the bearing lubrication of the axle. If there is obvious wear, replace or supplement it in time and make corresponding records.

[0044] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0045] 1. A wheel pressure test device for road pavement fatigue-wear-humidity and heat of the present invention provides a vertical load for a simulated vehicle-mounted component through an actuator, provides a driving force for a simulated vehicle-mounted component through a reciprocating motion unit, and simulates the increased friction force of the vehicle braking on the loading wheel and the test piece surface through a resistance simulation unit, so as to simulate various loads during vehicle driving.

[0046] 2. The present invention is a road pavement fatigue-wear-humidity wheel pressure test device, which controls the temperature and humidity of the test piece surface through a heating module and a humidification module to simulate a real operating scenario, comprehensively considers the impact of various adverse factors on the comprehensive performance of the test piece, and enhances the reliability of the test results.

[0047] 3. The wheel pressure test device for fatigue-wear-humidity and heat of pavement of the present invention can reflect the order of occurrence of different damage and failure modes of bridge pavement through real-scale tests, and clarify the key direction of pavement maintenance work. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 It is a schematic structural diagram of a wheel pressure test device for road pavement fatigue-wear-humidity and heat according to an embodiment of the present invention;

[0049] Figure 2 A schematic diagram of the structure of a vertical reaction frame of a wheel pressure test device for road pavement fatigue-wear-humidity and heat according to an embodiment of the present invention;

[0050] Figure 3 This is a schematic diagram of the structure of a loading unit of a wheel pressure test device for road pavement fatigue-wear-humidity and heat according to an embodiment of the present invention;

[0051] Figure 4 This is a schematic diagram of the actuator connection of a road pavement fatigue-wear-humidity and heat wheel pressure test device according to an embodiment of the present invention;

[0052] Figure 5 This is a schematic diagram of the structure of a simulated vehicle-mounted component of a wheel pressure test device for road pavement fatigue-wear-humidity and heat according to an embodiment of the present invention;

[0053] Figure 6 This is a schematic diagram of the structure of a reciprocating motion unit of a road pavement fatigue-wear-humidity and heat wheel pressure test device according to an embodiment of the present invention;

[0054] Figure 7 A side view of a simulated vehicle-mounted component structure of a wheel pressure test device for road pavement fatigue-wear-humidity and heat according to an embodiment of the present invention;

[0055] Figure 8 This is a schematic structural diagram of a resistance simulation unit of a road pavement fatigue-wear-humidity and heat wheel pressure test device according to an embodiment of the present invention;

[0056] Fig. 9 This is a schematic diagram of the resistance simulation unit structure of Example 2 of the present invention;

[0057] Fig.10 It is a schematic flow chart of a method for using a road pavement fatigue-wear-humidity and heat wheel pressure test device according to an embodiment of the present invention;

[0058] Fig.11 This is a specific flow chart of step S200 in a method for using a road pavement fatigue-wear-humidity and heat wheel pressure test device according to an embodiment of the present invention;

[0059] Fig.12 This is a specific flow chart of step S300 in a method for using a road pavement fatigue-wear-humidity and heat wheel pressure test device according to an embodiment of the present invention;

[0060] Fig.13 This is a specific flow chart of step S500 in a method for using a road pavement fatigue-wear-humidity and heat wheel pressure test device according to an embodiment of the present invention;

[0061] Fig.14 A schematic flow chart of a road pavement fatigue-wear-humidity and heat wheel pressure test method according to an embodiment of the present invention;

[0062] Fig.15 It is a schematic diagram of the change of driving force at various stages when a spring spring is used in a wheel pressure test method for road pavement fatigue-wear-humidity and heat according to an embodiment of the present invention;

[0063] Fig.16 It is a schematic diagram of the change of vertical pressure at various stages when a spring spring is used in a wheel pressure test method for road pavement fatigue-wear-humidity and heat according to an embodiment of the present invention;

[0064] Fig.17 It is a schematic diagram of the change of friction force at various stages when a spring spring is used in a wheel pressure test method for road pavement fatigue-wear-humidity and heat in an embodiment of the present invention;

[0065] Fig.18 It is a schematic diagram of the change of driving force at various stages when a brake structure or a damper is used in a wheel pressure test method for road pavement fatigue-wear-humidity and heat according to an embodiment of the present invention;

[0066] Fig.19 It is a schematic diagram of the change of vertical pressure at various stages when a brake structure or a damper is used in a wheel pressure test method for road pavement fatigue-wear-humidity and heat in an embodiment of the present invention;

[0067] Fig. 20 It is a schematic diagram of the change of the rotational resistance at various stages when a brake structure or a damper is used in a wheel pressure test method for road pavement fatigue-wear-humidity and heat in an embodiment of the present invention;

[0068] Fig.21 It is a schematic diagram of the change of friction force at various stages when a brake structure or a damper is used in a wheel pressure test method for road pavement fatigue-wear-humidity and heat in an embodiment of the present invention.

[0069] 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-simulated vehicle-mounted components, 251-vehicle body, 252-axle, 253-loading wheel, 254-guide wheel, 255-auxiliary wheel, 26-loading track, 3-reciprocating motion unit, 31-horizontal reaction frame, 32-motor mounting frame, 33-linear motor, 4-resistance simulation unit, 41-spring, 42-ratchet, 43-brake structure, 44-damper. DETAILED DESCRIPTION

[0070] 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.

[0071] Example 1

[0072] like Figure 1 As shown, an embodiment of the present invention provides a wheel pressure test device for fatigue-wear-humidity and heat of pavement, comprising: a vertical reaction frame 1, a loading unit 2 arranged between the vertical reaction frames 1, and a reciprocating motion unit 3. The loading unit 2 comprises an actuator 21 and a simulated vehicle-mounted component 25. The actuator 21 provides a vertical load to the simulated vehicle-mounted component 25 to simulate the dead weight of the vehicle. The reciprocating motion unit 3 provides a horizontal force to the simulated vehicle-mounted component 25, so that the simulated vehicle moves back and forth on the specimen, thereby realizing an effective loading test on the pavement or bridge deck structure. In addition, during the loading test, no manual participation is required. 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 pavement or steel bridge deck.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] like Figure 3 , 4 As 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. Each loading vertical beam 23 is provided with a loading track 26 at the bottom along the length direction. The loading track 26 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 crossbeam 22. The two ends of the loading crossbeam 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.

[0077] like Figure 5As shown, the simulated vehicle-mounted component 25 is arranged at the bottom of the loading vertical beam 23, including a vehicle body 251, a wheel axle 252 arranged at the bottom of the vehicle body 251, a loading wheel 253 arranged on the wheel axle 252, a guide wheel 254 arranged at the top of the vehicle body 251, and auxiliary wheels 255 arranged on both sides of the vehicle body 251. The vehicle body 251 is a plate-like structure, with a loading wheel mounting seat at the bottom, a guide wheel mounting seat at the top, and auxiliary wheel mounting seats on both sides. The wheel axle 252 is arranged on the loading wheel mounting seat, the guide wheel mounting seat, and the auxiliary wheel mounting seat. The loading wheel mounting seat is provided with at least four loading wheel mounting seats arranged in a square array, and the loading wheel 253 is mounted on the loading wheel mounting seat through the wheel axle 252, and the loading wheel 253 is in contact with the surface of the specimen, ensuring that the loading wheel 253 is uniformly stressed during vertical loading, and the vertical loading is maintained on the surface of the specimen without generating a deflection angle. The guide wheel mounting seat is provided at each of the four corners of the top of the vehicle body 251, and its width direction position corresponds to the position of the loading track 26. The guide wheel 254 is installed on the guide wheel mounting seat through the wheel axle 252, and its surface is provided with a groove along the circumference. The width of the groove is the same as the protrusion of the loading track 26, and the two form a fit. Two auxiliary wheel mounting seats are provided on each side of the vehicle body 251, and the auxiliary wheel 255 is also installed on the auxiliary wheel mounting seat through the wheel axle 252.

[0078] Preferably, the loading wheel 253 is a pneumatic tire, a solid rubber tire or a steel plate reinforced solid rubber tire, and the pressure between the loading wheel 253 and the sample is maintained between 0.7 MPa and 5 MPa.

[0079] Preferably, bearings are provided at the connection positions of the loading wheel 253 , the guide wheel 254 and the auxiliary wheel 255 to reduce the wear of the wheel shaft 252 .

[0080] like Figure 6As shown, a bearing platform is also provided at the bottom end of the column 11 and the same side as the guide seat 24, and the reciprocating motion unit 3 includes a horizontal reaction frame 31 provided on the bearing platform, a motor mounting frame 32 provided on the horizontal reaction frame 31, and a linear motor 33 provided on the motor mounting frame 32. The horizontal reaction frame 31 is a rectangular frame, which is fixedly connected to the bearing platform with high-strength bolts, clamped between the columns 11 of each vertical reaction frame 1, and is made of steel material not less than Q345, which is an I-shaped or square cross-section, and the surface is coated with anti-corrosion material. Anti-collision blocks are provided on the inner side of the horizontal plates along the width direction at both ends of the horizontal reaction frame 31, and the anti-collision blocks are made of rubber; guide auxiliary strips are provided on the inner side of the vertical plates along the length direction on both sides, and the guide auxiliary strips are made of smooth rigid materials. The motor mounting frame 32 spans the horizontal reaction frame 31 along the length direction of the horizontal reaction frame 31, and both ends are fixed on the horizontal plate of the horizontal reaction frame 31 along the width direction, and the central part of the fixed position is provided with a hollow, and the two ends of the hollow position are connected to serve as a mounting position. The linear motor 33 is installed in the motor mounting position of the motor mounting frame 32, and its output end is connected to the two ends of the vehicle body 251, and the connection is also connected by rotation. The auxiliary wheels 255 on both sides of the vehicle body 251 are in contact with the auxiliary strips on the inner side of the horizontal reaction frame 31, and when the linear motor 33 drives the simulated vehicle-mounted component 25 to move back and forth, it assists it not to deviate.

[0081] The linear motor 33 further includes a linear magnetic rail and a mover. The linear magnetic rail is fixed on the motor mounting frame 32 , and the mover is rotatably connected to two ends of the vehicle body 251 .

[0082] This test 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, a guard, a heating module and an alarm device, and the heating module includes a heating fan and a thermal sensor. 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 materials. The frame is also provided with structures of other equipment. The guard 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 of 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 air 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.

[0083] 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 component 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 through 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.

[0084] 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.

[0085] The environmental loading system also includes a humidification module, which is used to periodically replenish the moisture on the surface of the road and bridge deck pavement specimen, and is a nozzle array composed of multiple nozzles.

[0086] like Figure 7 , 8 As shown, the test device also includes a resistance simulation unit 4 arranged on the simulated vehicle-mounted component 25, and the resistance simulation unit 4 includes a spring 41 and a ratchet 42. Among them, one end of the spring 41 is connected to the loading wheel 253, and the other end is connected to the ratchet 42, and the ratchet 42 is arranged on the vehicle body 251. And the position of the simulated vehicle-mounted component 25 in the middle of the loading track 26 is taken as the starting position, and one end of it to the loading track 26 is taken as the maximum displacement position. When the simulated vehicle-mounted component 25 is in the starting position, the spring 41 is in the original length state, and the ratchet 42 is in the relaxed state. In the process of the simulated vehicle-mounted component 25 moving from the starting position to the maximum displacement position, the ratchet 42 is tightened, the spring 41 is stretched to generate tension elastic force, resulting in increasing torque resistance of the loading wheel 253; in the process of the simulated vehicle-mounted component 25 moving from the maximum displacement position to the starting position, the ratchet 42 is loosened, the spring 41 is quickly released, and no additional torque resistance is applied to the loading wheel 253.

[0087] During the test, the actuator 21 applies vertical pressure to the loading track 26, simulating the contact between the top of the vehicle-mounted component 25 and the loading track 26, and transmitting the vertical pressure to the road and bridge deck pavement specimen, applying an effective pressure exceeding the deadweight of the loaded vehicle body in the vertical downward direction, causing the specimen to accumulate vertical compression fatigue damage; in the process of the loaded vehicle body moving from the starting position to the maximum displacement position, the resistance simulation unit 4 applies additional torque resistance to the loading wheel 253. Since the loading wheel 253 is a driven wheel, the static friction between it and the road and bridge deck pavement is increased, causing the specimen to accumulate horizontal shear fatigue damage and surface wear damage.

[0088] The test device also includes a monitoring system and a control system. The monitoring system includes a sensor component, a three-dimensional laser scanner, an infrared camera and a fiber optic sensor. The sensor component is arranged in the simulated vehicle-mounted component 25 and the environmental loading system, including a force sensor, a displacement sensor, an acceleration sensor, a temperature sensor and a humidity sensor. The three-dimensional laser scanner is used to detect the degradation of the flatness of the test piece, and the degradation includes rutting, bulging and displacement. The infrared camera is used to detect cracking and water seepage on the surface of the test piece. The fiber optic sensor is an OFDR fiber optic sensor, which is realized by optical frequency domain reflection technology, arranged into a multi-layer orthogonal network and pre-buried in the test piece, and is used to measure the relative slip of different layers of the test piece.

[0089] The control system is used to control the operation of the loading unit 2, the environmental loading system, the resistance simulation unit 4 and the monitoring system.

[0090] Example 2

[0091] like Fig. 9 As shown, the resistance simulation unit 4 includes a brake structure 43, which is servo-controlled and has a brake pad inside. The brake pad is arranged on the outer periphery of the wheel axle 252. The position of the simulated vehicle-mounted component 25 in the middle of the loading track 26 is taken as the starting position, and the end of the simulated vehicle-mounted component 25 to the loading track 26 is the maximum displacement position. When the simulated vehicle-mounted component 25 is in the starting position, the brake structure 43 is in a relaxed state. In the process of the simulated vehicle-mounted component 25 moving from the starting position to the maximum displacement position, the brake pad is closed, and a constant braking torsional resistance is applied to the loading wheel 253; in the process of the simulated vehicle-mounted component 25 moving from the maximum displacement position to the starting position, the brake pad is released, and no additional torque resistance is applied to the loading wheel.

[0092] The loading process is controlled according to the horizontal motion state, which is divided into six stages: forward uniform acceleration motion, forward uniform speed motion, forward uniform deceleration motion, reverse uniform acceleration motion, reverse uniform speed motion, and reverse uniform deceleration motion. The forward and reverse uniform speed stages correspond to the tested section of the specimen.

[0093] Example 3

[0094] The resistance simulation unit 4 includes a damper 44, which is an eddy current damper. The damper 44 provides stable torque by energizing the electromagnet to provide resistance for the loading wheel 253. The position of the simulated vehicle-mounted component 25 in the middle of the loading track 26 is taken as the starting position, and the end of the simulated vehicle-mounted component 25 to the loading track 26 is the maximum displacement position. When the simulated vehicle-mounted component 25 is in the starting position, the damper 44 is in a power-off state. In the process of the simulated vehicle-mounted component 25 moving from the starting position to the maximum displacement position, the damper 44 is energized to apply a constant damping torque to the loading wheel 253; in the process of the simulated vehicle-mounted component 25 moving from the maximum displacement position to the starting position, the damper 44 is de-energized and no additional torque is applied to the loading wheel 253.

[0095] The loading process is controlled according to the horizontal motion state, which is divided into six stages: forward uniform acceleration motion, forward uniform speed motion, forward uniform deceleration motion, reverse uniform acceleration motion, reverse uniform speed motion, and reverse uniform deceleration motion. The forward and reverse uniform speed stages correspond to the tested section of the specimen.

[0096] Example 4

[0097] like Fig.10 As shown, an embodiment of the present invention provides a method for using a road pavement fatigue-wear-humidity wheel pressure test device, comprising the following steps:

[0098] 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;

[0099] 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;

[0100] 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 25, and starting the experiment;

[0101] 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;

[0102] S500, after the experiment is completed, the device is stopped in the order of deceleration and stop of the driving simulation vehicle-mounted component 25, unloading of the actuator 21, and cooling of the environment, and the test is terminated.

[0103] like Fig.11 As shown, step S200 is specifically as follows:

[0104] S201, disabling the loading and environmental loading functions of the actuator 21, gradually increasing the speed of the simulated vehicle-mounted component 25 from slow to fast, until the simulated vehicle-mounted component 25 reaches the designed loading speed and completes no less than ten cycles of reciprocation along the entire length of the loading track 26, and visually and sensor data are used to check the drive to ensure stable operation without abnormal noise or vibration;

[0105] S202, do not enable the environmental loading function, move the simulated vehicle-mounted component 25 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;

[0106] 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.

[0107] like Fig.12 As shown, step S300 is specifically as follows:

[0108] 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;

[0109] 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;

[0110] S303, start the linear motor 33 to drive the simulated vehicle-mounted component 25 to perform reciprocating motion and record the test process.

[0111] Step S400 specifically includes:

[0112] S401, when a short pause is required for observation during the test, only the speed of the simulated vehicle-mounted component 25 is reduced to 0, and the simulated vehicle-mounted component 25 is moved to the middle of the loading track 26, and the actuator and environmental load should be kept unchanged at this time;

[0113] 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 25 to slow down and stop, and the actuator 21 to unload.

[0114] 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.

[0115] like Fig.13 As shown, step S500 is specifically as follows:

[0116] S501, control the linear motor 33 to drive and decelerate until the speed of the simulated vehicle-mounted component 25 is reduced to 0, and move the simulated vehicle-mounted component 25 to the middle of the loading track 26;

[0117] S502, unloading the actuator 21 synchronously at a speed not exceeding 50 kN / min until the loading track 26 and the guide wheel of the simulated vehicle-mounted component 25 are clear;

[0118] S503, stop heating, wait for the ambient temperature to drop to room temperature or accelerate the cooling process by using a ventilation fan.

[0119] During the experiment, the normal operation and safety of the experiment must be maintained and the following standards must be implemented:

[0120] a. When the simulated vehicle-mounted component 25 is in a non-stationary state, it is not allowed to approach or touch the test device;

[0121] b. When the warning device of the environmental loading system lights up, it is not allowed to enter the enclosure;

[0122] c. When the simulated vehicle-mounted component 25 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.

[0123] 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.

[0124] Example 5

[0125] like Fig.14 As shown, an embodiment of the present invention provides a road pavement fatigue-wear-humidity wheel pressure test method, comprising the following steps:

[0126] T100. Determine the test parameters and the number of test cycles through theoretical analysis and sample tests. The test process is managed on a daily basis.

[0127] T200. Before starting the test every day, check the pavement temperature, adjust the output power of the heating module to ensure that the surface temperature of the specimen reaches between 55-65°C, and spray water on the specimen surface through the humidification module until the surface of the test section of the specimen is completely wet;

[0128] T300, start the device to conduct durability test on the surface of the test piece;

[0129] T400, after completing one cycle of loading, the fiber optic sensor samples at a frequency of 50Hz, and performs an additional 10 cycles of loading under the test load. The fiber optic sensor data is interpolated to generate the bridge deck pavement strain cloud map at different depths, and the slip between each layer is calculated;

[0130] T500, after resetting the simulated vehicle-mounted component 25 to the starting point, stop the operation of the device, photograph the surface of the specimen with an infrared camera at a fixed point, record the water seepage on the surface of the specimen in the test section, collect the flatness change of the specimen at a fixed point with a laser scanner, and record the data according to the loading date;

[0131] T600. After completing a cycle of testing, check that all equipment is in normal condition, ensure that the heating module continues to work, and that the rest of the equipment is powered off;

[0132] T700. Check the data recorded by the sensors in the simulated vehicle-mounted components 25 and the environmental loading system of the test on the day. If the relative value of the data to the test plan exceeds 10%, the device shall be repaired and the subsequent tests shall be carried out after the problem is eliminated;

[0133] T800. After every ten cycles of testing, check and evaluate the tire wear of the loading wheel 253 and the bearing lubrication of the axle 252. If there is obvious wear, replace or replenish them in time and make corresponding records.

[0134] like Figure 15-17 As shown, when the resistance simulation unit 4 adopts the combination of the clockwork spring 41 and the ratchet 42, the resistance simulation unit 4 is not controlled, but because the rotational resistance will change with the position of the loaded vehicle, the reciprocating driving force needs to be controlled accordingly, and the forces at each stage during the control cycle are shown in the figure.

[0135] like Figure 18-21 As shown, when the resistance simulation unit 4 adopts a brake structure 43 or a damper 44, it is necessary to control the resistance mechanism to provide a constant horizontal braking force in the forward uniform speed stage. The forces in each stage of the control cycle are shown in the figure.

[0136] 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 wheel pressure test device for road pavement fatigue, wear and damp heat, characterized in that: include: A loading unit (2), the loading unit (2) comprising an actuator (21), a simulated vehicle-mounted component (25) and a loading track (26); the simulated vehicle-mounted component (25) comprising a vehicle body (251), a wheel axle (252) arranged at the bottom of the vehicle body (251), a loading wheel (253) arranged on the wheel axle (252), a guide wheel (254) arranged at the top of the vehicle body (251) and auxiliary wheels (255) arranged at both sides of the vehicle body (251); An environmental loading system, the environmental loading system comprising a frame, enclosure, a heating module, a humidification module and an alarm device; A resistance simulation unit (4), the resistance simulation unit (4) being used to provide torque resistance for simulating a vehicle-mounted component (25); The position of the simulated vehicle-mounted component (25) in the middle of the loading track (26) is taken as the starting position, and the position to one end of the loading track (26) is the maximum displacement position.

2. A road pavement fatigue-wear-humidity wheel pressure test device according to claim 1, characterized in that: The resistance simulation unit (4) comprises a spring (41) and a ratchet (42); One end of the spring (41) is connected to the loading wheel (253), and the other end is connected to the ratchet (42). The ratchet (42) is arranged on the vehicle body (251). When the simulated vehicle-mounted component (25) is in the starting position, the spring (41) is in the original length state, and the ratchet (42) is in the relaxed state. During the process of the simulated vehicle-mounted component (25) moving from the starting position to the maximum displacement position, the ratchet wheel (42) is tightened and the spring spring (41) is stretched to generate tensioning elastic force, causing the torque resistance of the loading wheel (253) to become increasingly greater; During the process of the simulated vehicle-mounted component (25) moving from the maximum displacement position to the starting position, the ratchet wheel (42) is loosened and the spring spring (41) is quickly released, and no additional torque resistance is applied to the loading wheel (253).

3. A road pavement fatigue-wear-humidity wheel pressure test device according to claim 1, characterized in that: The resistance simulation unit (4) comprises a brake structure (43); The brake structure (43) is servo controlled and has a brake pad inside, which is arranged on the outer periphery of the wheel axle (252); When the simulated vehicle-mounted component (25) is in the starting position, the brake structure (43) is in a relaxed state; During the process of the simulated vehicle-mounted component (25) moving from the starting position to the maximum displacement position, the brake pad is closed, and a constant braking torsional resistance is applied to the loading wheel (253); during the process of the simulated vehicle-mounted component (25) moving from the maximum displacement position to the starting position, the brake pad is released, and no additional torque resistance is applied to the loading wheel.

4. A road pavement fatigue-wear-humidity wheel pressure test device according to claim 1, characterized in that: The resistance simulation unit (4) comprises a damper (44); The damper (44) is an eddy current damper, which provides stable torque by energizing the electromagnet, thereby providing resistance for the loading wheel (253); When the simulated vehicle-mounted component (25) is in the starting position, the damper (44) is in a power-off state; During the process of the simulated vehicle-mounted component (25) moving from the starting position to the maximum displacement position, the damper (44) is energized to apply a constant damping torque to the loading wheel (253); During the process of the simulated vehicle-mounted component (25) moving from the maximum displacement position to the starting position, the damper (44) is powered off and no additional torque is applied to the loading wheel (253).

5. A road pavement fatigue-wear-humidity wheel pressure test device according to any one of claims 1 to 4, characterized in that: The heating module includes a heating fan and a thermal sensor; The humidification module is used to periodically replenish the moisture on the surface of the road and bridge deck pavement specimen, and is a nozzle array composed of multiple nozzles.

6. A road pavement fatigue-wear-humidity wheel pressure test device according to any one of claims 1 to 4, characterized in that: It also includes monitoring systems; The monitoring system includes a sensor assembly, a three-dimensional laser scanner, an infrared camera and a fiber optic sensor.

7. A road pavement fatigue-wear-humidity wheel pressure test device according to claim 6, characterized in that: The sensor component is arranged in the simulated vehicle-mounted component (25) and the environmental loading system, and includes a force sensor, a displacement sensor, an acceleration sensor, a temperature sensor and a humidity sensor; The three-dimensional laser scanner is used to detect the degradation of the flatness of the test piece, which degradation includes rutting, bulging and displacement; The infrared camera is used to detect cracks and water seepage on the surface of the test piece; The optical fiber sensors are arranged into a multi-layer orthogonal network and pre-buried in the test piece, and are used to measure the relative slip conditions of different layers of the test piece.

8. A wheel pressure test device for road pavement fatigue-wear-humidity and heat according to any one of claims 1 to 4, characterized in that: Also includes control systems; The control system is used to control the operation of the loading unit (2), the environmental loading system, the resistance simulation unit (4) and the monitoring system.

9. A road pavement fatigue-wear-humidity wheel pressure test device according to any one of claims 1 to 4, characterized in that: The actuator (21) applies vertical pressure to the loading track (26), simulating the contact between the top of the vehicle-mounted component (25) and the loading track (26), and transmits the vertical pressure to the road and bridge deck pavement test piece, applying an effective pressure exceeding the deadweight of the loading vehicle in the vertical downward direction, so that the test piece accumulates vertical compression fatigue damage; During the movement of the loading vehicle body from the starting position to the maximum displacement position, the resistance simulation unit (4) applies additional torque resistance to the loading wheel (253), thereby increasing the static friction between the loading wheel and the road and bridge deck pavement, causing the test piece to accumulate horizontal shear fatigue damage and surface wear damage.

10. A road pavement fatigue-wear-humidity wheel pressure test method, implemented using a road pavement fatigue-wear-humidity wheel pressure test device as described in any one of claims 1 to 9, characterized in that: The following steps are involved: T100. Determine the test parameters and the number of test cycles through theoretical analysis and sample tests. The test process is managed on a daily basis. T200. Before starting the test every day, check the pavement temperature, adjust the output power of the heating module to ensure that the surface temperature of the specimen reaches between 55-65°C, and spray water on the specimen surface through the humidification module until the surface of the test section of the specimen is completely wet; T300, start the device to conduct durability test on the surface of the test piece; T400, after completing one cycle of loading, the fiber optic sensor samples at a frequency of 50 Hz, and performs additional (10) cycles of loading under the test load. The fiber optic sensor data is interpolated to generate the bridge deck pavement strain cloud map at different depths, and the slip between each layer is calculated; T500, after resetting the simulated vehicle-mounted component (25) to the starting point, stop the operation of the device, photograph the surface of the test piece with an infrared camera at a fixed point, record the water seepage on the surface of the test piece in the test section, collect the flatness change of the test piece at a fixed point with a laser scanner, and record the data according to the loading date; T600. After completing a cycle of testing, check that all equipment is in normal condition, ensure that the heating module continues to work, and that the rest of the equipment is powered off; T700. Check the data recorded by the sensors in the simulated vehicle-mounted components (25) and the environmental loading system of the test on the day. If the relative value between the data and the test plan exceeds 10%, repair the device and conduct subsequent tests after eliminating the problem; T800. After every ten cycles of testing, check and evaluate the tire wear of the loading wheel (253) and the bearing lubrication of the axle (252). If there is obvious wear, replace or replenish them in time and make corresponding records.

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