Automatic bridge actual stress testing system based on DIC technology

Abstract

The invention discloses a DIC technology-based bridge actual stress automatic test system, which comprises a fluorescent powder spraying device, a reflective powder spraying device, an image acquisition device and a data processing device, and is characterized in that the fluorescent powder spraying device is arranged on a wing plate of a concrete beam and is used for spraying fluorescent powder to a web plate of the concrete beam; forming a speckle layer; the reflective powder spraying device is arranged on a wing plate of the concrete beam and is used for spraying reflective powder to a web plate of the concrete beam to form a reflective layer so as to increase the contrast ratio of a speckle layer; the image acquisition device is arranged on a wing plate of the concrete beam, and the image acquisition device is used for acquiring image information of the speckle layer and the reflective layer; the beneficial effects of the invention are that the speckle contrast is enhanced through the reflective layer, and the problem of image blurring caused by direct strong light is solved.

Description

Technical Field

[0001] This application relates to the field of bridge monitoring, and in particular to an automated testing system for actual stress in bridges based on DIC technology. Background Technology

[0002] As a crucial node in transportation networks, the structural safety of bridges is directly related to the safety of people's lives and property and socio-economic development. In recent years, with the emergence of complex structures such as long-span bridges and cross-sea bridges, the service environment of bridges has become increasingly complex. They are subjected to vehicle loads, wind loads, temperature changes, and the effects of natural disasters over long periods, and the internal stress state of the structure is in a state of dynamic change. Digital image correlation (DIC), as a non-contact full-field strain measurement method, captures the displacement field of the structural surface by comparing images before and after deformation, and then calculates the strain and stress distribution. It has demonstrated the advantages of high precision and high resolution in laboratory research.

[0003] Chinese invention patent CN110470444A discloses an automated testing system for actual bridge stress based on DIC technology, comprising a camera, a phosphor spraying device, a computer, and a slide rail. The slide rail is installed on both sides of the upper flange of a box-type concrete beam. The phosphor spraying device is used to spray phosphor onto the web of the box-type concrete beam to form speckles with varying brightness. The camera is slidably connected to the slide rail via a bracket to capture the speckles and transmit the captured images to the computer. The computer is used to analyze and process the images captured by the camera and generate a stress time history diagram.

[0004] The aforementioned technologies have the following drawbacks: Bridges are exposed to the external environment for a long time. While the phosphor speckle has high contrast when the light is weak, it has low contrast when exposed to strong direct light, resulting in blurry images captured by the camera and affecting the monitoring quality. Summary of the Invention

[0005] To improve the contrast of phosphor speckle under strong direct light, this application provides an automated testing system for actual bridge stress based on DIC technology.

[0006] This application provides an automated testing system for actual bridge stress based on DIC technology, which adopts the following technical solution: An automated testing system for actual stress of bridges based on DIC technology includes a fluorescent powder spraying device, which is installed on the flange of a concrete beam and is used to spray fluorescent powder onto the web of the concrete beam to form a speckled layer. A reflective powder spraying device is installed on the flange of a concrete beam. The reflective powder spraying device is used to spray reflective powder onto the web of the concrete beam to form a reflective layer and increase the contrast of the speckle layer. An image acquisition device, mounted on the flange of a concrete beam, is used to acquire image information of the speckle layer and the reflective layer; and, A data processing device is connected to an image acquisition device and is used to process image information.

[0007] By adopting the above technical solution, a fluorescent powder spraying device is installed on the flange of the concrete beam to spray fluorescent powder onto the web, forming a speckle layer with random distribution characteristics. At the same time, a reflective powder spraying device is also set on the flange, spraying reflective powder onto the web to cover the surface of the speckle layer and form a reflective layer. The reflective powder has high reflectivity and can reflect light when exposed to strong direct light, making the fluorescent powder particles in the speckle layer more obvious in terms of light and dark contrast with the surrounding area. An image acquisition device is installed on the flange of the concrete beam. Under different lighting conditions, especially in strong light environments, the enhanced contrast of the reflective layer enables the image acquisition device to capture high-definition, high-contrast image information, avoiding the image quality degradation problem caused by speckle blur. The acquired image information is transmitted to the data processing device in real time via data cable or wireless transmission. After receiving the image information transmitted by the image acquisition device, the data processing device preprocesses the image to realize automated monitoring and analysis of the actual stress of the bridge.

[0008] Preferably, the fluorescent powder spraying device includes a first powder storage tank, a pump body, a pipe, and multiple nozzles disposed on the flange of the concrete beam. The first powder storage tank is used to store fluorescent powder. The outlet of the first powder storage tank is connected to the inlet of the pump body. The outlet of the pump body is connected to the inlet of the pipe. The outlet of the pipe is connected to the inlet of the nozzle. The multiple nozzles are spaced apart on the pipe. The outlet of the nozzles faces the web of the concrete beam.

[0009] By adopting the above technical solution, the first powder storage tank is fixed to the concrete beam flange and stores phosphor powder inside. The pump body draws in a mixture of phosphor powder and air through the inlet, so that the pressurized airflow is evenly distributed to each nozzle. The nozzle disperses the pressurized airflow into a fan-shaped mist field. The phosphor powder is accelerated in the high-speed airflow and impacts the web surface in a dispersed state to form a speckle layer of uniform thickness.

[0010] Preferably, the reflective powder spraying device includes a second powder storage tank disposed on the wing plate of the concrete beam. The second powder storage tank is used to store reflective powder, and the outlet of the second powder storage tank is connected to the inlet of the pump body.

[0011] By adopting the above technical solution, the second powder storage tank is fixedly installed on the flange of the concrete beam as a container for storing reflective powder. The outlet of the powder storage tank is connected to the inlet of the pump body. When the device is started, the pump body starts to operate, forming a negative pressure at the inlet, which draws in the reflective powder and air from the powder storage tank to form a gas-solid two-phase flow. The outlet of the pump body is connected to the inlet of the pipeline. The pressurized reflective powder gas-solid two-phase flow enters the pipeline, and the pipeline delivers the reflective powder to the nozzles near the web of the concrete beam. The nozzles are evenly spaced on the pipeline, and the outlet of the nozzles faces the web of the concrete beam. The sprayed reflective powder is driven by the high-speed airflow and impacts the surface of the web at a certain angle and speed to form a reflective layer.

[0012] Preferably, the testing system further includes a powder leveling device, which includes a sieve ball and a vibration assembly. The sieve ball is hinged inside a pipe, and the vibration assembly is disposed inside the sieve ball. The vibration assembly is used to drive the sieve ball to vibrate.

[0013] By adopting the above technical solution, the vibration component drives the sieve ball to vibrate at high frequency, so that the two powders entering the sieve ball repeatedly collide and interweave during the rolling and falling process, ensuring that the components are evenly distributed and avoiding local concentrations that are too high or too low, thus meeting the requirements for high-precision mixing.

[0014] Preferably, the vibration assembly includes a vibration motor and a protective cylinder, wherein the protective cylinder is disposed inside the sieve ball and the vibration motor is disposed inside the protective cylinder.

[0015] By adopting the above technical solution, the protective sleeve completely isolates the vibrating motor from the powder in the pipeline, preventing powder from entering the motor and reducing the cost of motor replacement and maintenance.

[0016] Preferably, the powder leveling device further includes multiple turbulence-disrupting blades, which are arranged in a ring around the protective cylinder.

[0017] By adopting the above technical solution, the turbulence blades change the flow trajectory of the powder in the pipe, so that the powder generates complex flow states such as eddies and turbulence when passing through the sieve ball area. Different types of powders can interweave and diffuse more fully, which significantly improves the mixing efficiency.

[0018] Preferably, the image acquisition device includes a guide rail, a camera, and a drive assembly. The guide rail is disposed on the flange of the concrete beam and extends along the length of the flange of the concrete beam. The camera is slidably connected to the guide rail, and the drive assembly is used to drive the camera to slide along the guide rail. The camera faces the web of the concrete beam.

[0019] By adopting the above technical solution, the drive component moves the camera to one end of the guide rail, and drives the camera to move along the guide rail. At the same time, the camera acquires web images at a preset frequency. The background system processes the continuously acquired images to generate complete visual data of the web surface. After completing one scan, the drive component can reset the camera to the starting point and repeat the acquisition to realize real-time monitoring of the state of the concrete beam.

[0020] Preferably, the drive assembly includes a rubber wheel and a motor. The rubber wheel is rotatably connected to the camera and slidably and rotatably connected to the guide rail. The motor is mounted on the camera, and the output shaft of the motor is coaxially connected to the rubber wheel.

[0021] By adopting the above technical solution, the rubber wheel is made of elastic rubber material and is installed on the camera. It is in close contact with the guide rail by gravity. When the motor drives the rubber wheel to rotate clockwise or counterclockwise, the static friction between the rubber wheel and the guide rail causes it to roll along the surface of the guide rail. Since the rubber wheel is rigidly connected to the camera, the camera moves linearly along the guide rail.

[0022] Preferably, the image acquisition device further includes a buffer assembly, which includes a first bracket, a second bracket, a hydraulic cylinder, and a spring. The rubber wheel is rotatably connected to the first bracket, the camera is mounted on the second bracket, the cylinder body of the hydraulic cylinder is connected to the second bracket, the piston rod of the hydraulic cylinder is connected to the first bracket, one end of the spring is connected to the cylinder body of the hydraulic cylinder, and the other end of the spring is connected to the piston rod of the hydraulic cylinder.

[0023] By adopting the above technical solution, the buffer assembly achieves dynamic buffering of impact vibrations during camera movement through the synergistic effect of hydraulic damping and spring elasticity, ensuring the stability of image acquisition. The first and second supports are flexibly connected by hydraulic cylinders and springs, rather than being directly rigidly fixed, to avoid direct transmission of impact energy to the camera. The hydraulic cylinder is filled with hydraulic oil. When the piston rod moves, the oil needs to flow between the two chambers of the cylinder through the throttling orifice, generating viscous resistance proportional to the movement speed. When the impact causes the piston rod to contract towards the cylinder, the oil in the rear chamber is squeezed through the throttling orifice to flow to the front chamber. The oil friction consumes the impact kinetic energy, slowing down the movement speed of the first support. After the impact disappears, the spring pushes the piston rod to reset, and the oil in the front chamber flows back to the rear chamber. The damping force suppresses the rebound oscillation during reset. During impact compression, the spring is compressed, converting mechanical energy into elastic potential energy, prolonging the impact time, and reducing the instantaneous impact force. After the impact disappears, the elastic potential energy is released, pushing the piston rod to reset slowly. At the same time, the damping force of the hydraulic cylinder prevents the spring from oscillating excessively.

[0024] Preferably, the image acquisition device further includes a buffer pad, which is disposed between the guide rail and the flange of the concrete beam, with both sides of the buffer pad abutting against the guide rail and the flange of the concrete beam, respectively.

[0025] By adopting the above technical solution, a buffer pad is set between the guide rail and the concrete beam flange. Through the deformation energy absorption of the elastic material and the damping effect of interface friction, the vibration suppression effect of the image acquisition device is further improved.

[0026] In summary, this application includes the following beneficial technical effects: by enhancing speckle contrast through a reflective layer, it solves the problem of image blurring caused by direct strong light, effectively copes with strong light environments, and also improves adaptability to other complex lighting conditions. Attached Figure Description

[0027] Figure 1 This is a first-view overall structural diagram of the testing system provided by the present invention; Figure 2 This is a schematic diagram of the overall structure of the testing system provided by the present invention from a second perspective; Figure 3 This is a first-view overall structural schematic diagram of the powder homogenizing device provided by the present invention; Figure 4 This is a second-view overall structural schematic diagram of the powder homogenizing device provided by the present invention.

[0028] Figure label: 1. Fluorescent powder spraying device; 11. First powder storage tank; 12. Pump body; 13. Pipeline; 14. Nozzle; 2. Concrete beam; 21. Wing plate; 22. Web plate; 3. Reflective powder spraying device; 31. Second powder storage tank; 4. Image acquisition device; 41. Guide rail; 42. Camera; 43. Drive assembly; 431. Rubber wheel; 432. Motor; 44. Buffer assembly; 441. First support; 442. Second support; 443. Hydraulic cylinder; 444. Spring; 45. Buffer pad; 6. Powder leveling device; 61. Screen ball; 62. Vibration assembly; 621. Vibration motor; 622. Protective cylinder; 63. Turbulence blade. Detailed Implementation

[0029] The following is in conjunction with the appendix Figures 1-4 This application will be described in further detail.

[0030] This invention provides an automated testing system for actual bridge stress based on DIC technology, the structure of which is as follows: Figures 1-4 As shown, it includes a phosphor spraying device 1, a reflective powder spraying device 3, an image acquisition device 4, and a data processing device.

[0031] The fluorescent powder spraying device 1 is installed on the flange 21 of the concrete beam 2. The fluorescent powder spraying device 1 is used to spray fluorescent powder onto the web 22 of the concrete beam 2 to form a speckled layer.

[0032] The reflective powder spraying device 3 is installed on the flange 21 of the concrete beam 2. The reflective powder spraying device 3 is used to spray reflective powder onto the web 22 of the concrete beam 2 to form a reflective layer and increase the contrast of the speckle layer.

[0033] Image acquisition device 4 is installed on the flange 21 of concrete beam 2. Image acquisition device 4 is used to acquire image information of speckle layer and reflective layer.

[0034] The data processing device is connected to the image acquisition device 4, and the data processing device is used to process image information.

[0035] In use, the fluorescent powder spraying device 1 is installed on the flange 21 of the concrete beam 2 and sprays fluorescent powder onto the web 22 to form a speckle layer with random distribution characteristics. At the same time, the reflective powder spraying device 3 is also set on the flange 21 and sprays reflective powder onto the web 22 to form a reflective layer on the surface of the speckle layer. The reflective powder has high reflectivity and can reflect light when exposed to strong direct light, making the fluorescent powder particles in the speckle layer more obvious in terms of light and dark contrast with the surrounding area. The image acquisition device 4 is installed on the flange 21 of the concrete beam 2. Under different lighting conditions, especially in strong light environments, the enhanced contrast of the reflective layer enables the image acquisition device 4 to capture high-definition, high-contrast image information, avoiding the image quality degradation problem caused by speckle blur. The acquired image information is transmitted to the data processing device in real time via data cable or wireless transmission. After receiving the image information transmitted by the image acquisition device 4, the data processing device preprocesses the image to realize automated monitoring and analysis of the actual stress of the bridge.

[0036] In this invention, the contrast of speckle is enhanced by a reflective layer, which solves the problem of image blurring caused by direct strong light. It effectively copes with strong light environments and also improves adaptability to other complex lighting conditions.

[0037] To spray fluorescent powder onto the web 22 of the concrete beam 2, please refer to... Figure 1 In a preferred embodiment, the phosphor spraying device 1 includes a first powder storage tank 11, a pump body 12, a pipe 13, and a plurality of nozzles 14 disposed on the wing plate 21 of the concrete beam 2. The first powder storage tank 11 is used to store phosphor. The outlet of the first powder storage tank 11 is connected to the inlet of the pump body 12. The outlet of the pump body 12 is connected to the inlet of the pipe 13. The outlet of the pipe 13 is connected to the inlet of the nozzles 14. The plurality of nozzles 14 are spaced apart on the pipe 13. The outlet of the nozzles 14 faces the web plate 22 of the concrete beam 2.

[0038] In use, the first powder storage tank 11 is fixed to the wing plate 21 of the concrete beam 2 and stores fluorescent powder inside. The pump body 12 draws in a mixture of fluorescent powder and air through the inlet, so that the pressurized airflow is evenly distributed to each nozzle 14. The nozzle 14 disperses the pressurized airflow into a fan-shaped mist field. The fluorescent powder is accelerated in the high-speed airflow and impacts the surface of the web plate 22 in a dispersed state to form a speckle layer of uniform thickness.

[0039] To apply reflective powder to the web 22 of the concrete beam 2, please refer to... Figure 2 In a preferred embodiment, the reflective powder spraying device 3 includes a second powder storage tank 31 disposed on the wing plate 21 of the concrete beam 2. The second powder storage tank 31 is used to store reflective powder, and the outlet of the second powder storage tank 31 is connected to the inlet of the pump body 12.

[0040] In use, the second powder storage tank 31 is fixedly installed on the wing plate 21 of the concrete beam 2 as a container for storing reflective powder. The outlet of the second powder storage tank 31 is connected to the inlet of the pump body 12. When the device is started, the pump body 12 starts to operate, forming a negative pressure at the inlet, which draws in the reflective powder and air from the second powder storage tank 31 to form a gas-solid two-phase flow. The outlet of the pump body 12 is connected to the inlet of the pipe 13. The pressurized reflective powder gas-solid two-phase flow enters the pipe 13. The pipe 13 delivers the reflective powder to the nozzles 14 near the web plate 22 of the concrete beam 2. The nozzles 14 are evenly spaced on the pipe 13, and the outlet of the nozzles 14 faces the web plate 22 of the concrete beam 2. The sprayed reflective powder is driven by the high-speed airflow and impacts the surface of the web plate 22 at a certain angle and speed to form a reflective layer.

[0041] To ensure a more uniform mixing of the phosphor and reflective powder, please refer to... Figure 2 In a preferred embodiment, the testing system further includes a powder leveling device 6, which includes a sieve ball 61 and a vibration component 62. The sieve ball 61 is hinged inside the pipe 13, and the vibration component 62 is disposed inside the sieve ball 61. The vibration component 62 is used to drive the sieve ball 61 to vibrate.

[0042] During use, the vibration component 62 drives the sieve ball 61 to vibrate at high frequency, causing the two powders entering the sieve ball 61 to collide and interweave repeatedly during the rolling and falling process, ensuring that the components are evenly distributed and avoiding situations where the local concentration is too high or too low, thus meeting the requirements for high-precision mixing.

[0043] To reduce the possibility of damage to the vibration motor 621, please refer to... Figure 3 In a preferred embodiment, the vibration assembly 62 includes a vibration motor 621 and a protective cylinder 622. The protective cylinder 622 is disposed inside the sieve ball 61, and the vibration motor 621 is disposed inside the protective cylinder 622.

[0044] During use, the protective sleeve 622 completely isolates the vibration motor 621 from the powder in the pipe 13, preventing the powder from entering the motor 432 and reducing the replacement and maintenance costs of the motor 432.

[0045] To further improve the uniformity of the mixing of phosphor and reflective powder, please refer to... Figure 3 In a preferred embodiment, the powder leveling device 6 further includes a plurality of turbulence-disrupting blades 63, which are arranged around the protective cylinder 622.

[0046] When in use, the turbulence blades 63 change the flow trajectory of the powder in the pipe 13, causing the powder to generate complex flow states such as eddies and turbulence when passing through the area of ​​the sieve ball 61. Different types of powders can interpenetrate and diffuse more fully, significantly improving the mixing efficiency.

[0047] To collect speckle data in real time, please refer to... Figure 2 In a preferred embodiment, the image acquisition device 4 includes a guide rail 41, a camera 42, and a drive assembly 43. The guide rail 41 is disposed on the flange 21 of the concrete beam 2 and extends along the length of the flange 21 of the concrete beam 2. The camera 42 is slidably connected to the guide rail 41. The drive assembly 43 is used to drive the camera 42 to slide along the guide rail 41. The camera 42 faces the web 22 of the concrete beam 2.

[0048] In use, the drive component 43 moves the camera 42 to one end of the guide rail 41. The drive component 43 drives the camera 42 to move along the guide rail 41. At the same time, the camera 42 acquires images of the web 22 at a preset frequency. The background system processes the continuously acquired images to generate complete visual data of the surface of the web 22. After completing one scan, the drive component 43 can reset the camera 42 to the starting point and repeat the acquisition to realize real-time monitoring of the state of the concrete beam 2.

[0049] To drive the camera 42 to move, please refer to... Figure 2 In a preferred embodiment, the drive assembly 43 includes a rubber wheel 431 and a motor 432. The rubber wheel 431 is rotatably connected to the camera 42 and is slidably and rotatably connected to the guide rail 41. The motor 432 is mounted on the camera 42, and the output shaft of the motor 432 is coaxially connected to the rubber wheel 431.

[0050] In use, the rubber wheel 431 is made of elastic rubber material and is installed on the camera 42. It is in close contact with the guide rail 41 by gravity. When the motor 432 drives the rubber wheel 431 to rotate clockwise or counterclockwise, the static friction between the rubber wheel 431 and the guide rail 41 causes it to roll along the surface of the guide rail 41. Since the rubber wheel 431 is rigidly connected to the camera 42, the camera 42 moves linearly along the guide rail 41.

[0051] To reduce camera shake, please refer to... Figure 2 In a preferred embodiment, the image acquisition device 4 further includes a buffer assembly 44, which includes a first bracket 441, a second bracket 442, a hydraulic cylinder 443, and a spring 444. A rubber wheel 431 is rotatably connected to the first bracket 441, a camera 42 is mounted on the second bracket 442, the cylinder body of the hydraulic cylinder 443 is connected to the second bracket 442, the piston rod of the hydraulic cylinder 443 is connected to the first bracket 441, one end of the spring 444 is connected to the cylinder body of the hydraulic cylinder 443, and the other end of the spring 444 is connected to the piston rod of the hydraulic cylinder 443.

[0052] In use, the buffer assembly 44, through the synergistic effect of hydraulic damping and the elasticity of the spring 444, dynamically buffers the impact vibrations during the movement of the camera 42, ensuring the stability of image acquisition. The first bracket 441 and the second bracket 442 are flexibly connected by a hydraulic cylinder 443 and a spring 444, rather than being directly rigidly fixed, to prevent the impact energy from being directly transmitted to the camera 42. The hydraulic cylinder 443 is filled with hydraulic oil. When the piston rod moves, the oil needs to flow between the two chambers of the cylinder through a throttling orifice, generating viscous resistance proportional to the movement speed. Impact causes the piston rod to move. When the piston rod retracts into the cylinder, the oil in the rear chamber is squeezed through the throttle orifice and flows into the front chamber. The oil friction consumes the impact kinetic energy, slowing down the movement speed of the first support 441. After the impact disappears, the spring 444 pushes the piston rod to reset, and the oil in the front chamber flows back to the rear chamber. The damping force suppresses the rebound oscillation during reset. During impact compression, the spring 444 is compressed, converting mechanical energy into elastic potential energy, prolonging the impact time, and reducing the instantaneous impact force. After the impact disappears, the elastic potential energy is released, pushing the piston rod to reset slowly. At the same time, the damping force of the hydraulic cylinder 443 prevents the spring 444 from oscillating excessively.

[0053] To further reduce camera shake, please refer to... Figure 2 In a preferred embodiment, the image acquisition device 4 further includes a buffer pad 45, which is disposed between the guide rail 41 and the wing plate 21 of the concrete beam 2, with both sides of the buffer pad 45 abutting against the guide rail 41 and the wing plate 21 of the concrete beam 2, respectively.

[0054] In use, the buffer pad 45 is placed between the guide rail 41 and the wing plate 21 of the concrete beam 2. Through the deformation energy absorption of the elastic material and the damping effect of interface friction, the vibration suppression effect of the image acquisition device 4 is further improved.

[0055] The implementation principle of an automated bridge actual stress testing system based on DIC technology in this application embodiment is as follows: A fluorescent powder spraying device 1 is installed on the flange 21 of the concrete beam 2 and sprays fluorescent powder onto the web 22 to form a speckle layer with random distribution characteristics. At the same time, a reflective powder spraying device 3 is also set on the flange 21 and sprays reflective powder onto the web 22 to form a reflective layer on the surface of the speckle layer. The reflective powder has high reflectivity and can reflect light when strong light shines directly on it, making the fluorescent powder particles in the speckle layer more obvious in terms of light and dark contrast with the surrounding area. An image acquisition device 4 is installed on the flange 21 of the concrete beam 2. Under different lighting conditions, especially in strong light environments, the enhanced contrast of the reflective layer enables the image acquisition device 4 to capture high-definition, high-contrast image information, avoiding the image quality degradation problem caused by speckle blur. The acquired image information is transmitted to the data processing device in real time via data cable or wireless transmission. After receiving the image information transmitted by the image acquisition device 4, the data processing device preprocesses the image to realize automated monitoring and analysis of the actual stress of the bridge.

[0056] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. An automated testing system for actual bridge stress based on DIC technology, characterized in that, include: A fluorescent powder spraying device (1) is installed on the flange (21) of the concrete beam (2). The fluorescent powder spraying device (1) is used to spray fluorescent powder onto the web (22) of the concrete beam (2) to form a speckled layer. Reflective powder spraying device (3), the reflective powder spraying device (3) is installed on the wing plate (21) of the concrete beam (2), the reflective powder spraying device (3) is used to spray reflective powder onto the web plate (22) of the concrete beam (2) to form a reflective layer to increase the contrast of the speckle layer. An image acquisition device (4) is mounted on the flange (21) of the concrete beam (2). The image acquisition device (4) is used to acquire image information of the speckle layer and the reflective layer; and, A data processing device is connected to an image acquisition device (4) and is used to process image information.

2. The automated bridge actual stress testing system based on DIC technology according to claim 1, characterized in that: The fluorescent powder spraying device (1) includes a first powder storage tank (11), a pump body (12), a pipe (13), and a plurality of nozzles (14) disposed on the wing plate (21) of the concrete beam (2). The first powder storage tank (11) is used to store fluorescent powder. The outlet of the first powder storage tank (11) is connected to the inlet of the pump body (12). The outlet of the pump body (12) is connected to the inlet of the pipe (13). The outlet of the pipe (13) is connected to the inlet of the nozzles (14). The plurality of nozzles (14) are spaced apart on the pipe (13). The outlet of the nozzles (14) faces the web plate (22) of the concrete beam (2).

3. The automated bridge actual stress testing system based on DIC technology according to claim 2, characterized in that: The reflective powder spraying device (3) includes a second powder storage tank (31) disposed on the wing plate (21) of the concrete beam (2). The second powder storage tank (31) is used to store reflective powder, and the outlet of the second powder storage tank (31) is connected to the inlet of the pump body (12).

4. The automated bridge actual stress testing system based on DIC technology according to claim 2, characterized in that: The testing system also includes a powder leveling device (6), which includes a sieve ball (61) and a vibration component (62). The sieve ball (61) is hinged inside the pipe (13), and the vibration component (62) is located inside the sieve ball (61). The vibration component (62) is used to drive the sieve ball (61) to vibrate.

5. The automated bridge actual stress testing system based on DIC technology according to claim 4, characterized in that: The vibration assembly (62) includes a vibration motor (621) and a protective cylinder (622). The protective cylinder (622) is located inside the sieve ball (61), and the vibration motor (621) is located inside the protective cylinder (622).

6. The automated bridge actual stress testing system based on DIC technology according to claim 5, characterized in that: The powder leveling device (6) also includes a plurality of turbulence-disrupting blades (63), which are arranged around the protective cylinder (622).

7. The automated bridge actual stress testing system based on DIC technology according to claim 1, characterized in that: The image acquisition device (4) includes a guide rail (41), a camera (42), and a drive assembly (43). The guide rail (41) is mounted on the flange (21) of the concrete beam (2) and extends along the length of the flange (21) of the concrete beam (2). The camera (42) is slidably connected to the guide rail (41). The drive assembly (43) is used to drive the camera (42) to slide along the guide rail (41). The camera (42) faces the web (22) of the concrete beam (2).

8. The automated bridge actual stress testing system based on DIC technology according to claim 7, characterized in that: The drive assembly (43) includes a rubber wheel (431) and a motor (432). The rubber wheel (431) is rotatably connected to the camera (42) and is slidably and rotatably connected to the guide rail (41). The motor (432) is mounted on the camera (42) and the output shaft of the motor (432) is coaxially connected to the rubber wheel (431).

9. The automated bridge actual stress testing system based on DIC technology according to claim 8, characterized in that: The image acquisition device (4) further includes a buffer assembly (44), which includes a first bracket (441), a second bracket (442), a hydraulic cylinder (443), and a spring (444). The rubber wheel (431) is rotatably connected to the first bracket (441), the camera (42) is mounted on the second bracket (442), the cylinder body of the hydraulic cylinder (443) is connected to the second bracket (442), the piston rod of the hydraulic cylinder (443) is connected to the first bracket (441), one end of the spring (444) is connected to the cylinder body of the hydraulic cylinder (443), and the other end of the spring (444) is connected to the piston rod of the hydraulic cylinder (443).

10. The automated bridge actual stress testing system based on DIC technology according to claim 7, characterized in that: The image acquisition device (4) also includes a buffer pad (45), which is located between the guide rail (41) and the wing plate (21) of the concrete beam (2). The two sides of the buffer pad (45) abut against the guide rail (41) and the wing plate (21) of the concrete beam (2), respectively.

Images