Fatigue damage detection device for reinforced concrete

Abstract

The invention belongs to the technical field of concrete detection, and particularly relates to a reinforced concrete fatigue damage detection device which comprises a bottom plate and a mounting frame, a carrier plate is fixed to the top of the bottom plate, a mounting groove is formed in the middle protrusion of the top of the carrier plate, a concrete test piece is mounted in the mounting groove, and a plurality of testing wheels are arranged on the front face of the mounting frame. The device further comprises an acoustic emission detection module, a control module, a load simulation mechanism and a strain detection module. The acoustic emission detection modules are used for detecting the mean value and variance of damage differences between the adjacent acoustic emission detection modules, and the strain detection module is used for detecting the surface strain of the concrete test piece. According to the invention, the control module receives data collected by the acoustic emission detection module and the strain detection module in real time, carries out comprehensive analysis, then generates an evaluation coefficient, compares the evaluation coefficient with a preset evaluation coefficient reference threshold, judges when to apply a proper load to the mounting rack, and simulates a complex load under a real working condition.

Description

Technical Field

[0001] The present invention relates to the technical field of concrete detection, and in particular to a fatigue damage detection device for reinforced concrete. Background Art

[0002] Reinforced concrete structures are widely used in civil engineering. Infrastructure such as bridges, roads, and buildings are subject to repeated loads from vehicles and wind over long periods of time, making them highly susceptible to fatigue damage. Once fatigue damage occurs, a structure's load-bearing capacity gradually decreases, and in severe cases, it can even lead to structural failure, endangering life and property. Traditional methods for detecting fatigue damage in reinforced concrete rely on regular manual inspections, which are not only inefficient but also difficult to detect subtle internal damage.

[0003] After searching, the Chinese patent with the authorization announcement number CN218036106U discloses a fatigue detection device for the development of steel fiber concrete for urban roads. It includes a base, a load-bearing plate, a weight sensor, a guide rod, and an adjustment motor. The upper surface of the base is internally mounted with a sliding load-bearing plate, and the weight sensor is installed inside the base directly below the load-bearing plate. The side surface of the mounting plate is fixedly mounted with a detection motor, and the output shaft of the detection motor passes through the inner surface of the mounting plate and is fixedly connected to the rotating shaft of a wheel on one side. Although the existing technical problems have been solved, the following problems still exist:

[0004] Although this technical solution involves simulating the load applied to the road surface during vehicle driving, it cannot simulate the complex loads under real working conditions. Therefore, corresponding improvements are made to address this problem. Summary of the Invention

[0005] Based on the technical problems existing in the prior art, the present invention proposes a fatigue damage detection device for reinforced concrete.

[0006] The present invention proposes a fatigue damage detection device for reinforced concrete, comprising a base plate and a mounting frame, wherein a carrier plate is fixed on the top of the base plate, a mounting groove is provided at the middle bulge on the top of the carrier plate, a concrete specimen is mounted in the mounting groove, an elastic connection is formed between the mounting frame and the base plate, a plurality of test wheels which can move along a circular path and roll the concrete specimens in sequence are arranged on the front of the mounting frame, and the mounting frame also comprises an acoustic emission detection module, a control module, a load simulation mechanism and a strain detection module; the acoustic emission detection module is provided with four symmetrically distributed ones for real-time detection of the mean and variance of damage differences between adjacent acoustic emission detection modules, the strain detection module is used for real-time detection of the surface strain of the concrete specimen, and the load simulation mechanism is used for applying a load to the mounting frame; the plurality of test wheels move along the circular path and then roll the concrete specimens in sequence, In the process of simulating the vehicle rolling action, the acoustic emission detection module detects the mean and variance of the damage differences between adjacent acoustic emission detection modules, the strain detection module detects the surface strain of the concrete specimen, and the control module receives the data collected by the acoustic emission detection module and the strain detection module in real time, and performs comprehensive analysis, and then generates an evaluation coefficient. By comparing the evaluation coefficient with the pre-set evaluation coefficient reference threshold, it is determined when to apply a suitable load to the mounting frame, and the working state of the actuator is controlled according to the comparison result. When it is necessary to apply a suitable load to the mounting frame, the load simulation mechanism will start and apply a suitable load to the mounting frame, thereby simulating the load applied to the concrete specimen when the vehicle is driving, thereby simulating the complex load under real working conditions, creating a more realistic experimental environment, and improving the accuracy of the experimental results.

[0007] Preferably, the control module is installed on the mounting frame, the acoustic emission detection module is installed in the mounting groove and is located on the bottom surface of the concrete specimen, and the strain detection module is pre-buried inside the concrete specimen; in this way, the mean and variance of the damage differences between adjacent acoustic emission detection modules can be better detected in real time through the acoustic emission detection module, and the surface strain of the concrete specimen can be better detected in real time through the strain detection module.

[0008] Preferably, an annular slide rail is fixed on the front of the mounting frame, and a plurality of sliding members distributed along the annular path are arranged in the annular slide rail, and the test wheel is rotatably connected to the corresponding sliding member, and a pair of runners are rotatably connected to the front of the mounting frame, and the two runners are connected by a crawler track, and a driving motor is fixed on the back of the mounting frame, and the output shaft of the driving motor is fixedly connected to one of the runners, and a plurality of push rods for pushing the sliding member are fixed on the outer surface of the crawler track; one of the runners is driven to rotate by the output shaft of the driving motor, and then the two runners and the crawler transmission cooperate to drive the crawler track to drive the push rod to move along the annular path, and the push rod will push the sliding member and the test wheel to move along the annular path, so that the test wheel rolls the concrete specimen in sequence.

[0009] Preferably, the sliding member includes a T-shaped main board, the back of which is rotatably connected to an intermediate wheel and a pair of auxiliary wheels symmetrically distributed about the intermediate wheel; this enables the intermediate wheel to stably move along the path of the annular slide rail.

[0010] Preferably, the load simulation mechanism includes a pair of fixing frames fixed on the top of the carrier plate, a hydraulic cylinder is fixed on the top of the fixing frame, the output shaft of the hydraulic cylinder is fixedly connected to a pressure block, and a pair of force blocks located below the corresponding pressure blocks are fixed on the front of the mounting frame; when the hydraulic cylinder receives the corresponding instruction from the control module, it will start, and then the output shaft of the hydraulic cylinder will drive the pressure block to move downward and press down the force block, thereby applying the system set pressure to the mounting frame, thereby simulating the load of the vehicle on the road.

[0011] Preferably, a plurality of evenly distributed inner tubes are fixed at the bottom of the mounting frame, a sleeve is sleeved on the bottom end of the inner tube, the bottom end of the sleeve is fixed to the bottom plate, a spring is sleeved on the inner tube, and the two ends of the spring are fixedly connected to the sleeve and the inner tube respectively; through the cooperation between the sleeve, the inner tube and the spring, an elastic connection can be formed between the mounting frame and the bottom plate, thereby roughly simulating the shock absorption system of the vehicle.

[0012] Preferably, the input and output ends of the acoustic emission detection module are electrically connected to the output and input ends of the control module respectively, the input and output ends of the strain detection module are electrically connected to the output and input ends of the control module respectively, and the output end of the control module is electrically connected to the input end of the hydraulic cylinder.

[0013] Preferably, the load simulation mechanism adopts closed-loop feedback control, and the control logic is as follows:

[0014] 1. Set target pressure based on the evaluation coefficient;

[0015] 2. Real-time dynamic adjustment of the hydraulic cylinder's oil pressure through PID algorithm.

[0016] Preferably, the calculation formula of the evaluation coefficient is:

[0017]

[0018] Where, : Surface strain of concrete specimen, , : weight coefficient, : yield strain of concrete, : Normalized damage index.

[0019] Preferably, the control module simulates the triggering conditions for the acceleration of the vehicle driving process through the device as follows: When the drive motor is started, it accelerates instantly .

[0020] Compared with the prior art, the present invention provides a fatigue damage detection device for reinforced concrete, which has the following beneficial effects:

[0021] 1. A fatigue damage detection device for reinforced concrete. This device uses multiple test wheels to move along a circular path to sequentially roll concrete specimens, simulating the rolling action of a vehicle. A load simulation mechanism applies a load to the mounting frame. A sleeve, inner tube, and spring form an elastic connection to simulate a vehicle's shock absorption system, creating a realistic experimental environment in all directions and ensuring that the test results are more in line with actual conditions.

[0022] 2. A reinforced concrete fatigue damage detection device. Its acoustic emission detection module, strain detection module, and control module work together to collect data in real time and generate an evaluation coefficient. This coefficient is compared with a reference threshold to control the operation of the load simulation mechanism. The calculation of the evaluation coefficient comprehensively considers key factors such as the concrete specimen's surface strain and weight coefficient. Closed-loop feedback control dynamically adjusts the hydraulic cylinder oil pressure in real time, significantly improving detection accuracy.

[0023] 3. A reinforced concrete fatigue damage detection device. The control module is electrically connected to all components, enabling an automated process for data collection, analysis, decision-making, and execution. Furthermore, by pre-setting trigger conditions, such as instantaneous acceleration of the drive motor when specific conditions are met, simulating the acceleration of a car in motion, this reduces manual intervention and improves detection efficiency and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a front structural schematic diagram of a reinforced concrete fatigue damage detection device proposed by the present invention;

[0025] Figure 2 This is a schematic diagram of the back structure of a reinforced concrete fatigue damage detection device proposed by the present invention;

[0026] Figure 3 This is a schematic diagram of the internal structure of a carrier plate of a reinforced concrete fatigue damage detection device proposed by the present invention;

[0027] Figure 4 This is a schematic diagram of the internal structure of an annular slide rail of a reinforced concrete fatigue damage detection device proposed by the present invention;

[0028] Figure 5 This is a schematic structural diagram of a sliding member of a reinforced concrete fatigue damage detection device proposed by the present invention;

[0029] Figure 6 For the present invention Figure 2 A schematic diagram of the enlarged structure at point A;

[0030] Figure 7This is a schematic diagram of a reinforced concrete fatigue damage detection device proposed by the present invention.

[0031] In the figure: 1. Base plate; 2. Carrier plate; 3. Mounting frame; 4. Mounting slot; 5. Concrete specimen; 6. Acoustic emission detection module; 7. Control module; 8. Test wheel; 9. Annular slide rail; 10. Rotating wheel; 11. Track; 12. Drive motor; 13. Push rod; 14. Main board; 15. Intermediate wheel; 16. Auxiliary wheel; 17. Fixed frame; 18. Hydraulic cylinder; 19. Pressure block; 20. Load block; 21. Casing; 22. Inner tube; 23. Spring. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0033] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as limiting the present invention.

[0034] Reference Figure 1-Figure 7 A reinforced concrete fatigue damage detection device includes a base plate 1 and a mounting frame 3. A carrier plate 2 is fixed to the top of the base plate 1. A mounting groove 4 is formed at the middle protrusion on the top of the carrier plate 2. A concrete specimen 5 is mounted in the mounting groove 4. The mounting frame 3 and the base plate 1 are elastically connected. The front of the mounting frame 3 is provided with multiple test wheels 8 that can move along a circular path and sequentially roll the concrete specimen 5. The device also includes an acoustic emission detection module 6, a control module 7, a load simulation mechanism, and a strain detection module.

[0035] The acoustic emission detection modules 6 are provided with four symmetrically distributed ones, which are used to detect the damage difference mean and variance between adjacent acoustic emission detection modules 6 in real time; the strain detection module is used to detect the surface strain of the concrete specimen 5 in real time; and the load simulation mechanism is used to apply a load to the mounting frame 3;

[0036] It should be noted that the acoustic emission detection module 6 can be an acoustic emission sensor or other device capable of detecting the mean and variance of damage differences between adjacent acoustic emission sensors in real time, the strain detection module can be a strain gauge or other device capable of detecting the surface strain of the concrete specimen 5 in real time, and the control module 7 is an embedded controller (such as the STM32 series) with an integrated data fusion algorithm. Therefore, the acoustic emission detection module 6, the strain detection module, and the control module 7 are not specifically limited here and can be selected according to actual needs;

[0037] During use, multiple test wheels 8 move along a circular path and then roll over the concrete specimen 5 in turn, thereby simulating the rolling action of a vehicle. During this process, the acoustic emission detection module 6 detects the mean and variance of the damage differences between adjacent acoustic emission detection modules 6, and the strain detection module detects the surface strain of the concrete specimen 5. The control module 7 receives the data collected by the acoustic emission detection module 6 and the strain detection module in real time, and performs a comprehensive analysis, and then generates an evaluation coefficient. By comparing the evaluation coefficient with a pre-set evaluation coefficient reference threshold, it is determined when to apply a suitable load to the mounting frame 3, and the working state of the actuator is controlled according to the comparison result. When it is necessary to apply a suitable load to the mounting frame 3, the load simulation mechanism will be started to apply a suitable load to the mounting frame 3, thereby simulating the load applied to the concrete specimen 5 when the vehicle is driving, thereby creating a more realistic experimental environment and improving the accuracy of the experimental results.

[0038] Among them, the control module 7 is installed on the mounting frame 3, the acoustic emission detection module 6 is installed in the mounting groove 4 and is located on the bottom surface of the concrete specimen 5, and the strain detection module is pre-buried inside the concrete specimen 5;

[0039] When in use, the acoustic emission detection module 6 can better detect the damage difference mean and variance between adjacent acoustic emission detection modules 6 in real time, and the strain detection module can better detect the surface strain of the concrete specimen 5 in real time.

[0040] Among them, the front of the mounting frame 3 is fixed with an annular slide rail 9, and a plurality of sliding members distributed along an annular path are provided in the annular slide rail 9. The test wheel 8 is rotatably connected to the corresponding sliding member. The front of the mounting frame 3 is rotatably connected to a pair of running wheels 10, and the two running wheels 10 are connected by a crawler 11. The back of the mounting frame 3 is fixed with a drive motor 12, and the output shaft of the drive motor 12 is fixedly connected to one of the running wheels 10. The outer surface of the crawler 11 is fixed with a plurality of push rods 13 for pushing the sliding members.

[0041] When in use, one of the wheels 10 is driven to rotate by the output shaft of the driving motor 12, and then the two wheels 10 and the track 11 cooperate to drive the track 11 to drive the push rod 13 to move along the circular path, and the push rod 13 will push the sliding part and the test wheel 8 to move along the circular path, so that the test wheel 8 rolls the concrete specimen 5 in turn.

[0042] The sliding member includes a T-shaped main plate 14, the back of which is rotatably connected to an intermediate wheel 15 and a pair of auxiliary wheels 16 symmetrically distributed about the intermediate wheel 15;

[0043] When in use, the intermediate wheel 15 can stably move along the path of the annular slide rail 9 .

[0044] The load simulation mechanism includes a pair of fixing frames 17 fixed to the top of the carrier plate 2. A hydraulic cylinder 18 is fixed to the top of the fixing frame 17. The output shaft of the hydraulic cylinder 18 is fixedly connected to a pressure block 19. A pair of force blocks 20 are fixed to the front of the mounting frame 3 and are located below the corresponding pressure blocks 19.

[0045] When in use, the hydraulic cylinder 18 will start after receiving the corresponding instruction from the control module 7, and then the output shaft of the hydraulic cylinder 18 will drive the pressure block 19 to move downward and press down the force block 20, thereby applying the system-set pressure to the mounting frame 3, thereby simulating the load of the vehicle on the road.

[0046] Among them, a plurality of evenly distributed inner tubes 22 are fixed at the bottom of the mounting frame 3, and the bottom end of the inner tube 22 is sleeved with a sleeve 21, and the bottom end of the sleeve 21 is fixed to the bottom plate 1. A spring 23 is sleeved on the inner tube 22, and the two ends of the spring 23 are fixedly connected to the sleeve 21 and the inner tube 22 respectively;

[0047] During use, the sleeve 21 , the inner tube 22 and the spring 23 cooperate to form an elastic connection between the mounting bracket 3 and the base plate 1 , thereby roughly simulating the formation of a vehicle's shock absorption system.

[0048] Among them, the input end and output end of the acoustic emission detection module 6 are electrically connected to the output end and input end of the control module 7 respectively, the input end and output end of the strain detection module are electrically connected to the output end and input end of the control module 7 respectively, and the output end of the control module 7 is electrically connected to the input end of the hydraulic cylinder 18.

[0049] In another embodiment, the control logic for automatically applying an appropriate load to the mounting frame 3 using closed-loop feedback control is as follows through the coordination between the acoustic emission detection module 6, the strain detection module, the control module 7, and the load simulation mechanism:

[0050] 1. Target pressure setting: ( is the static axle load, is the dynamic load factor);

[0051] 2. Real-time adjustment: Dynamically adjust the oil pressure through the PID algorithm. The formula is: ,in, , are PID parameters.

[0052] In the above, the calculation formula of the evaluation coefficient is:

[0053]

[0054] Where, : Surface strain of concrete specimen 5, , : weight coefficient, : yield strain of concrete (calibrated according to material), : Normalized damage index ( , ), : Damage index, : The mean damage difference between adjacent sensors, :variance.

[0055] In addition, the control module 7 can also simulate the acceleration of the car's driving process through the device to create a more realistic driving environment. The triggering conditions for simulating the acceleration of the car's driving process are as follows: When the drive motor 12 is started, the instantaneous acceleration ( ).

[0056] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0057] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0058] In the several embodiments provided in this application, it should be understood that the disclosed overall system, device and method can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another overall system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0059] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0060] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0061] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A reinforced concrete fatigue damage detection device, comprising a base plate (1) and a mounting frame (3), characterized in that: A carrier plate (2) is fixed on the top of the base plate (1), a mounting groove (4) is provided at a middle bulge on the top of the carrier plate (2), a concrete test piece (5) is installed in the mounting groove (4), an elastic connection is formed between the mounting frame (3) and the base plate (1), a front face of the mounting frame (3) is provided with a plurality of test wheels (8) capable of moving along a circular path and rolling the concrete test pieces (5) in sequence, and also includes an acoustic emission detection module (6), a control module (7), a load simulation mechanism and a strain detection module; The acoustic emission detection modules (6) are provided with four symmetrically distributed ones for real-time detection of the mean and variance of damage differences between adjacent acoustic emission detection modules (6); the strain detection module is used for real-time detection of the surface strain of the concrete specimen (5); and the load simulation mechanism is used for applying a load to the mounting frame (3); The control module (7) receives the data collected by the acoustic emission detection module (6) and the strain detection module and generates an evaluation coefficient, compares it with a preset reference threshold, and controls the working state of the load simulation mechanism according to the comparison result.

2. The reinforced concrete fatigue damage detection device according to claim 1, characterized in that: The control module (7) is mounted on the mounting frame (3), the acoustic emission detection module (6) is mounted in the mounting groove (4) and located on the bottom surface of the concrete specimen (5), and the strain detection module is pre-buried inside the concrete specimen (5).

3. The reinforced concrete fatigue damage detection device according to claim 1, characterized in that: The front of the mounting frame (3) is fixed with an annular slide rail (9), and a plurality of sliding members distributed along an annular path are arranged in the annular slide rail (9). The test wheel (8) is rotatably connected to the corresponding sliding member. The front of the mounting frame (3) is rotatably connected with a pair of rotating wheels (10), and the two rotating wheels (10) are connected by a crawler (11). The back of the mounting frame (3) is fixed with a driving motor (12), and the output shaft of the driving motor (12) is fixedly connected to one of the rotating wheels (10). The outer surface of the crawler (11) is fixed with a plurality of push rods (13) for pushing the sliding members.

4. The reinforced concrete fatigue damage detection device according to claim 3, characterized in that: The sliding member comprises a T-shaped main board (14), the back side of which is rotatably connected to an intermediate wheel (15) and a pair of auxiliary wheels (16) symmetrically distributed about the intermediate wheel (15).

5. The reinforced concrete fatigue damage detection device according to claim 3, characterized in that: The load simulation mechanism comprises a pair of fixing frames (17) fixed on the top of the carrier plate (2), a hydraulic cylinder (18) is fixed on the top of the fixing frame (17), an output shaft of the hydraulic cylinder (18) is fixedly connected to a pressure block (19), and a pair of force blocks (20) respectively located below the corresponding pressure blocks (19) are fixed on the front of the mounting frame (3).

6. The reinforced concrete fatigue damage detection device according to claim 1, characterized in that: A plurality of evenly distributed inner tubes (22) are fixed to the bottom of the mounting frame (3), a sleeve (21) is sleeved on the bottom end of the inner tube (22), the bottom end of the sleeve (21) is fixed to the bottom plate (1), a spring (23) is sleeved on the inner tube (22), and both ends of the spring (23) are fixedly connected to the sleeve (21) and the inner tube (22), respectively.

7. The reinforced concrete fatigue damage detection device according to claim 5, characterized in that: The input end and output end of the acoustic emission detection module (6) are electrically connected to the output end and input end of the control module (7), respectively; the input end and output end of the strain detection module are electrically connected to the output end and input end of the control module (7), respectively; and the output end of the control module (7) is electrically connected to the input end of the hydraulic cylinder (18).

8. The reinforced concrete fatigue damage detection device according to claim 5, characterized in that: The load simulation mechanism adopts closed-loop feedback control, and the control logic is as follows:

1. Set target pressure based on the assessment coefficient; Second, the oil pressure of the hydraulic cylinder (18) is dynamically adjusted in real time through the PID algorithm.

9. The reinforced concrete fatigue damage detection device according to claim 8, characterized in that: The calculation formula of the evaluation coefficient is: Where, : Surface strain of concrete specimen 5, , : weight coefficient, : yield strain of concrete, : Normalized damage index.

10. The reinforced concrete fatigue damage detection device according to claim 8, characterized in that: The control module (7) simulates the triggering conditions of the vehicle driving process acceleration through the device as follows: When the speed reaches 0.0500 V, the drive motor (12) is started to accelerate instantaneously.

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