A method for analyzing deformation of reinforced concrete components

Abstract

The present invention relates to the technical field of deformation analysis of reinforced concrete components, and discloses a method for analyzing the deformation of reinforced concrete components, including: reinforced concrete beams, columns and shear wall components, the reinforced concrete components are cantilever components, and have potential plastic hinge areas at the fixed ends of the cantilever components; laser displacement meters and 3D photogrammetry are used to measure the overall deformation and local deformation of the components respectively. The bending deformation, shear deformation and sliding deformation of the components are obtained by digital image correlation technology analysis, and the proportion of bending deformation, shear deformation and sliding deformation in the total displacement is further calculated to evaluate the failure mode of the reinforced concrete components. This technology measures the deformation of reinforced concrete components through laser displacement meters and three-dimensional photogrammetry non-contact measurement technology, reduces the interference of specimen damage and human factors on data acquisition during the test, and greatly improves the test accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of deformation analysis of reinforced concrete components, and in particular to a deformation measurement and analysis method of reinforced concrete components based on non-contact photogrammetry technology and digital image correlation (DIC) technology. Background Art

[0002] Reinforced concrete beams, columns and shear walls are the main load-bearing components in building structures. The failure modes under horizontal earthquakes are mainly divided into three types: bending failure, shear failure and bending-shear failure. Bending failure is ductile failure, which has obvious signs before failure; while shear failure is brittle failure, and the components will quickly lose their bearing capacity without signs before failure, posing a major safety hazard. Therefore, controlling the failure mode of reinforced concrete components is of great significance for evaluating and improving the seismic resistance of structures.

[0003] The experimental study of the failure mode and seismic performance of reinforced concrete components can provide an effective data basis and basis for the seismic design of reinforced concrete structures. In the test, the deformation of reinforced concrete components is measured by arranging displacement meters, and then the percentage of deformation components such as bending, shear and slip in the total deformation can be obtained by analyzing the deformation composition, and then the failure mode and stress performance of the components can be analyzed. During the loading process of reinforced concrete components, the cracking and spalling of concrete will interfere with the traditional displacement measurement. At the same time, due to the interference of human factors, the results of traditional displacement measurement are usually large in error, and even the data is invalid and it is impossible to obtain ideal test results. Summary of the invention

[0004] The technical problem to be solved by the present invention is to solve the problem that in the prior art, the measurement of reinforced concrete components is disturbed by concrete damage and human factors, resulting in large errors, easily leading to data failure and failure to obtain ideal test results.

[0005] The present invention adopts the following technical solution: a method for analyzing the deformation of reinforced concrete components, comprising the following steps:

[0006] (1) A reinforced concrete member is provided, one end of which is anchored on the rigid ground through a ground beam, and the other end of which is connected to a horizontal loading actuator as a loading end. The reinforced concrete member has at least one fixed end, and the fixed end has a potential plastic hinge area;

[0007] (2) Use laser displacement meter to measure the displacement of the loading end, and use 3D photogrammetry system to measure the local deformation of the fixed end;

[0008] (3) Digital image correlation technology is used to analyze the full-field displacement and strain of the fixed end, and a virtual extensometer is arranged to calculate the bending deformation, shear deformation and slip deformation. The total displacement measured by the laser displacement meter is compared and analyzed to evaluate the calculation error, and the proportion of various deformation components is further analyzed;

[0009] The step (3) specifically includes the following steps:

[0010] S1: Use a three-dimensional non-contact optical photography measurement system to collect full-field strain and full-field displacement within 1.5 times the width of the bottom of the specimen; use a laser displacement meter to collect the horizontal displacement of the top of the specimen;

[0011] S2: Use digital image correlation technology to perform strain analysis on the data collected by 3D photogrammetry to determine the height of the plastic hinge area at the limit state and ensure that the DIC calculation area can cover the plastic hinge area of ​​the specimen;

[0012] S3: Full-field strain and displacement data extracted using digital image correlation techniques are used to calculate lateral deformations caused by bending, shear, and slip, respectively;

[0013] S4: Calculation of bending deformation , the calculation of bending deformation includes the following steps:

[0014] The bottom DIC measurement area is divided into multiple sections with vertical extensometers. The vertical deformation of each section is measured to calculate the curvature. The height of each section is 5cm~10cm, and the average curvature of each section is Calculate using formula (1):

[0015] (1)

[0016] In the formula, and For the The vertical deformation on the left and right sides of the segment, For the The vertical distance between the upper and lower measuring points of the segment, is the horizontal distance between the left and right measuring points; therefore, the column is bent and deformed Calculate according to formula (2):

[0017] (2)

[0018] In the formula, is the number of segments within the column bottom measurement range, is the column height, The bottom of the column Segment height, is the curvature of the top interval of the measurement area;

[0019] S5: Calculation of shear deformation Calculation of shear deformation includes the following steps: Arrange diagonal extensometers within the DIC measurement range, obtain the shear deformation of the measured range through the change in the length of the extensometer, and then calculate the total shear deformation of the column. , as shown in formula (3):

[0020] (3)

[0021] In the formula, and are the initial lengths of the two diagonal extensometers in the measurement area, and are the deformation of the two butt-jointed extensometers, The height of the diagonal extensometer arrangement range;

[0022] S6: Calculate the slip deformation ; Calculating the slip deformation includes the following steps:

[0023] An extensometer is placed at the column bottom at the slip crack to measure the width of the slip crack, and then the deformation caused by slip is calculated according to formula (4): :

[0024] (4)

[0025] In the formula, is the slip crack width, is the horizontal distance from the slip crack measurement point to the compression edge of the column. If there are multiple slip cracks, the total slip deformation is obtained by adding the slip deformations of multiple cracks.

[0026] S7: Add the calculated bending deformation, shear deformation and slip deformation to obtain the total deformation of the top of the component, compare it with the deformation measured by the laser displacement meter, and evaluate the calculation error;

[0027] S8: Further calculate the proportion of each deformation component:

[0028] Bending deformation ratio:

[0029]

[0030] Shear deformation ratio:

[0031]

[0032] Slip deformation ratio:

[0033] .

[0034] Preferably, the reinforced concrete member is a cantilever member, a fixed end of which is anchored on the rigid ground through a ground beam, and a free end is connected to a horizontal actuator head to apply a horizontal force.

[0035] Preferably, the base of the reinforced concrete component is firmly connected to the rigid ground through ground anchors and hydraulic jacks.

[0036] Preferably, the three-dimensional non-contact optical photogrammetry system is composed of a non-contact photogrammetry system, a data acquisition system and a data analysis system, which work together to achieve real-time capture of the displacement and strain field of the component during the stress process.

[0037] Preferably, in step S1, a laser displacement meter is used to measure the displacement of the loading end, and a 3D photogrammetry system is used to measure the displacement and deformation of the fixed end. A surface of the fixed end parallel to the loading direction is used as the observation surface, and the height of the observation area is 1.5 times the width of the observation surface.

[0038] Before the specimen is loaded, the measuring surface of the specimen is first painted with matte white paint, and then the measuring area is painted with matte speckles using a speckle roller;

[0039] During the speckle production process, it is necessary to ensure that the speckle size is uniform and randomly distributed, with high black and white contrast and a measurement requirement of 50% each. After the speckle production is completed, before the test begins, the three-dimensional measurement head is placed at a horizontal distance of 1.5m from the measurement surface of the specimen, and the horizontal position of the camera is fine-tuned until the speckle on the measurement surface can be clearly photographed. Then the camera is adjusted to the center height of the speckle field and the crosshairs of the left and right cameras are ensured to be in the same position. After adjusting the lighting, camera focal length and aperture size, the measurement head camera is calibrated. After the equipment is adjusted, the test begins.

[0040] Preferably, during the test, the image acquisition is arranged to be synchronized with the load and displacement test data and acquired at the same frequency.

[0041] Preferably, the range of the plastic hinge zone in step S2 is determined based on the strain analysis of the bottom area of ​​the specimen. At the limit state, the height of the plastic hinge is determined by using the strain value of the concrete on the surface of the specimen obtained by digital image correlation calculation; the area where the tensile strain of the concrete at the same position on the component surface as the outermost longitudinal reinforcement is greater than 0.002 or the absolute value of the compressive strain of the concrete on the component surface is greater than 0.002 is the area where plastic deformation occurs, and the height of this area is the height of the plastic hinge zone.

[0042] Preferably, for the arrangement of measuring points for calculating bending deformation, equidistant extensometers are arranged longitudinally at a distance of 50 mm from the left and right edges of the specimen, with a spacing of 5 cm to 10 cm between the extensometers; for the arrangement of measuring points for calculating shear deformation, two diagonal extensometers are arranged with a distance of 50 mm from the left and right edges of the specimen as the boundary; for the arrangement of measuring points for calculating slip deformation, there will be a large strain value in the direction perpendicular to the development of the crack, so the larger cracks or bottom lifting on the surface of the specimen are found according to the strain diagram, and then the horizontal cracks or bottom lifting that cause the positive and reverse slip of the specimen are judged in combination with the test record photos, and the extensometers perpendicular to them are arranged respectively.

[0043] Preferably, the sum of the bending deformation, shear deformation and sliding deformation obtained by digital image correlation technology is compared with the reading of the laser displacement meter, and the error is controlled within 5%, and then the proportion of each deformation component is further calculated; in order to obtain a more accurate total displacement, it is necessary to arrange speckles on the ground beam to monitor the horizontal displacement during the loading process, and compare the horizontal displacement of the ground beam with the sum of the above three deformations and the degree of the laser displacement meter.

[0044] The present invention has the following beneficial effects: the present invention proposes a method for deformation measurement and deformation analysis of reinforced concrete components based on non-contact photogrammetry technology and DIC technology. Compared with traditional displacement meters, strain gauges and other measurement methods that can only obtain local displacement, the DIC technology can more accurately extract the full-field strain and displacement within the measurement range, and is not affected by the damage of the specimen during the measurement process. The measurement accuracy of the strain can reach 50 , the displacement accuracy can reach 0.01mm. The data extracted by DIC are then used to calculate the specific deformation amounts of bending deformation, shear deformation, and sliding deformation, and the proportion of each deformation is further calculated, and then the deformation type of the dominant component failure is inferred, which is helpful for analyzing the failure mode of the component. This calculation method can provide a basis for the prediction of the failure mode of reinforced concrete vertical components, and has important scientific research significance and practical engineering application value for evaluating the seismic capacity of structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 Collecting site pictures for the three-dimensional non-contact optical photogrammetry system of the present invention;

[0046] Figure 2 It is a flow chart of deformation analysis of reinforced concrete components based on DIC technology of the present invention;

[0047] Figure 3 It is a schematic diagram of the arrangement of measuring points within the DIC measurement range of the present invention;

[0048] FIG4 (a) is a schematic diagram of the bending deformation calculation of the present invention;

[0049] FIG4( b ) is a schematic diagram of shear deformation calculation according to the present invention;

[0050] FIG4( c ) is a schematic diagram of the slip deformation calculation of the present invention.

[0051] Figure numerals: 1-reinforced concrete component, 2-ground beam, 3-speckle area, 4-rigid ground, 5-horizontal loading actuator, 6-laser displacement meter, 7-3D photogrammetry system, 8-data acquisition system, 9-DIC analysis system. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, 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 part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the invention claimed for protection, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0053] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0054] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0055] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0056] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0057] Example

[0058] See also Figures 1 to 3 The present invention provides a method for analyzing the deformation of reinforced concrete components, which comprises the following steps:

[0059] (1) A reinforced concrete member is provided, one end of which is anchored on the rigid ground through a ground beam, and the other end of which is connected to a horizontal loading actuator as a loading end. The reinforced concrete member has at least one fixed end, and the fixed end has a potential plastic hinge area;

[0060] (2) Use laser displacement meter to measure the displacement of the loading end, and use 3D photogrammetry system to measure the local deformation of the fixed end;

[0061] (3) Digital image correlation technology is used to analyze the full-field displacement and strain of the fixed end. A virtual extensometer is arranged to calculate the bending deformation, shear deformation and slip deformation. The total displacement is compared with the total displacement measured by the laser displacement meter to evaluate the calculation error, and then the proportion of various deformation components is further analyzed.

[0062] The step (3) comprises the following steps:

[0063] S1: Use a three-dimensional non-contact optical photography measurement system to collect full-field strain and full-field displacement within 1.5 times the width of the bottom of the specimen; use a laser displacement meter to collect the horizontal displacement of the top of the specimen;

[0064] In this embodiment, it is ensured that the reinforced concrete component 1 to be tested is a cantilever structure and has at least one fixed end with a potential plastic hinge zone. One end is anchored to the rigid ground 4 through the ground beam 2, and the other end is connected to the horizontal loading actuator 5 as the loading end. The ground beam 2 needs to be firmly connected to the rigid ground 4 through the ground anchor and the hydraulic jack. Ensure that there is no relative displacement between the ground beam 2 and the rigid ground 4 during the loading test. At the same time, a laser displacement meter 6 is set up at the loading point of the horizontal actuator 5 at the loading end to collect the horizontal displacement of the top of the specimen.

[0065] In this embodiment, before the specimen is loaded, the specimen measurement surface is first painted with matte white paint, and then the observation area is painted with matte speckle using a speckle roller to ensure that the speckle area 3 completely covers the observation area. During the speckle production process, it is necessary to ensure that the speckle size is uniform and randomly distributed, and the black and white have high contrast and account for about 50% of each measurement requirement.

[0066] A surface at the fixed end parallel to the loading direction is taken as the observation surface, and the height of the observation area is 1.5 times the width of the observation surface.

[0067] In this embodiment, after the speckle production is completed before the specimen is loaded, the 3D photogrammetry system 7 is placed at a horizontal distance of about 1.5m from the specimen measurement surface before the test begins, and the horizontal position of the camera is fine-tuned until the speckle on the measurement surface can be clearly photographed. Then the camera is adjusted to the center height of the speckle field and the crosshairs of the left and right cameras are ensured to be in the same position. After adjusting the lighting, camera focal length and aperture size, the measuring head camera is calibrated, and the test is started after the equipment is adjusted. During the test, the image acquisition is set to be synchronized with the test data such as load and displacement at the same frequency.

[0068] S2: Use digital image correlation (DIC) technology to perform strain analysis on the data collected by 3D photogrammetry to determine the height of the plastic hinge area at the limit state and ensure that the DIC calculation area can cover the plastic hinge area of ​​the specimen;

[0069] In this embodiment, according to the strain analysis of the bottom area of ​​the specimen, at the limit state, the height of the plastic hinge is determined by using the concrete strain value of the specimen surface calculated by DIC. The method for determining the height of the plastic hinge area is that the area where the tensile strain of the concrete at the same position on the surface of the component and the outermost longitudinal reinforcement is greater than 0.002 or the absolute value of the compressive strain of the concrete on the surface of the component is greater than 0.002 is the area where plastic deformation occurs, and the height of this area is the height of the plastic hinge area.

[0070] S3: See Figures 4(a)-4(c) of the specification for calculating the lateral deformation caused by bending, shear and slip respectively using the full-field strain and displacement data extracted by DIC technology;

[0071] S4: Calculation of bending deformation

[0072] In this embodiment, regarding the arrangement of the measurement points for calculating the bending deformation, the bottom DIC measurement area is divided into multiple sections and vertical extensometers are arranged to measure the vertical deformation of each section to calculate the curvature. The height of each section can be 5cm-10cm, and the average curvature of each section is Calculate using formula (1):

[0073] (1)

[0074] In the formula, and For the The vertical deformation on the left and right sides of the segment, For the The vertical distance between the upper and lower measuring points of the segment, is the horizontal distance between the left and right measuring points; therefore, the column is bent and deformed Calculate according to formula (2):

[0075] (2)

[0076] In the formula, is the number of segments within the column bottom measurement range, is the column height, The bottom of the column Segment height, is the curvature of the top interval of the measurement area;

[0077] S5: Calculation of shear deformation

[0078] In this embodiment, regarding the arrangement of the measuring points for calculating the shear deformation, diagonal extensometers are arranged within the DIC measurement range. Specifically, for the arrangement of the measuring points for calculating the shear deformation, two diagonal extensometers are arranged with a distance of 50 mm from the left and right edges of the specimen as the boundary; the shear deformation of the measured range is obtained by the change in the length of the extensometer, and then the total shear deformation of the column is calculated. , as shown in formula (3):

[0079] (3)

[0080] In the formula, and are the initial lengths of the two diagonal extensometers in the measurement area, and are the deformation of the two butt-jointed extensometers, The height of the diagonal extensometer arrangement range;

[0081] S6: Calculate the slip deformation ; Calculating the slip deformation includes the following steps:

[0082] In this embodiment, regarding the arrangement of the measurement points for calculating the slip deformation, an extensometer is arranged at the slip crack at the bottom of the column. Specifically, for the arrangement of the measurement points for calculating the slip deformation, there will be a large strain value in the direction perpendicular to the crack development. Therefore, according to the strain diagram, a large crack on the surface of the specimen or the bottom lifting is found. Then, combined with the test record photos, the horizontal crack or bottom lifting that causes the forward and reverse slip of the specimen is judged, and the extensometers perpendicular to it are arranged respectively. The initial lengths S1 and S2 of the extensometers on the left and right sides are recommended to be 10 cm, which can also be selected according to the actual situation; the width of the slip crack is measured, and then the deformation caused by the slip is calculated according to formula (4) :

[0083] (4)

[0084] In the formula, is the slip crack width, is the horizontal distance from the slip crack measurement point to the compression edge of the column. If there are multiple slip cracks, the total slip deformation is obtained by adding the slip deformations of multiple cracks.

[0085] Regarding the method of determining the slip crack, there will be a larger strain value in the direction perpendicular to the crack development, so according to the strain diagram, find the larger cracks on the surface of the specimen or the bottom lifting. Then, combined with the test record photos, determine the horizontal cracks or bottom lifting that cause the specimen to slip in the forward and reverse directions, and take it as the slip crack of the specimen.

[0086] S7: Add the calculated bending deformation, shear deformation and slip deformation to obtain the total deformation of the top of the component, compare it with the deformation measured by the laser displacement meter, evaluate the calculation error, and control the error within 5%. If a more accurate total displacement is required, a speckle pattern can be arranged on the ground beam to monitor the horizontal displacement during loading, and the horizontal displacement of the ground beam and the sum of the above three deformations are compared with the reading of the laser displacement meter.

[0087] S8: Further calculate the proportion of each deformation component:

[0088] After correctly calculating the value of each deformation, substitute it into the formula to calculate the proportion of each deformation under the displacement angle. The calculation formulas are as follows.

[0089] Bending deformation ratio:

[0090]

[0091] Shear deformation ratio:

[0092]

[0093] Slip deformation ratio:

[0094]

[0095] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for analyzing the deformation of reinforced concrete components, characterized in that: The steps include: (1) A reinforced concrete member is provided, one end of which is anchored on the rigid ground through a ground beam, and the other end of which is connected to a horizontal loading actuator as a loading end. The reinforced concrete member has at least one fixed end, and the fixed end has a potential plastic hinge area; (2) Use laser displacement meter to measure the displacement of the loading end, and use 3D photogrammetry system to measure the local deformation of the fixed end; (3) Digital image correlation technology is used to analyze the full-field displacement and strain of the fixed end, and a virtual extensometer is arranged to calculate the bending deformation, shear deformation and slip deformation. The total displacement measured by the laser displacement meter is compared and analyzed to evaluate the calculation error, and the proportion of various deformation components is further analyzed; The step (3) specifically includes the following steps: S1: Use a three-dimensional non-contact optical photography measurement system to collect full-field strain and full-field displacement within 1.5 times the width of the bottom of the specimen; use a laser displacement meter to collect the horizontal displacement of the top of the specimen; S2: Use digital image correlation technology to perform strain analysis on the data collected by 3D photogrammetry to determine the height of the plastic hinge area at the limit state and ensure that the DIC calculation area can cover the plastic hinge area of ​​the specimen; S3: Full-field strain and displacement data extracted using digital image correlation techniques are used to calculate lateral deformations caused by bending, shear, and slip, respectively; S4: Calculation of bending deformation , the calculation of bending deformation includes the following steps: The bottom DIC measurement area is divided into multiple sections with vertical extensometers. The vertical deformation of each section is measured to calculate the curvature. The height of each section is 5cm~10cm, and the average curvature of each section is Calculate using formula (1): (1) In the formula, and For the The vertical deformation on the left and right sides of the segment, For the The vertical distance between the upper and lower measuring points of the segment, is the horizontal distance between the left and right measuring points; therefore, the column is bent and deformed Calculate according to formula (2): (2) In the formula, is the number of segments within the column bottom measurement range, is the column height, The bottom of the column Segment height, is the curvature of the top interval of the measurement area; S5: Calculation of shear deformation Calculation of shear deformation includes the following steps: Arrange diagonal extensometers within the DIC measurement range, obtain the shear deformation of the measured range through the change in the length of the extensometer, and then calculate the total shear deformation of the column. , as shown in formula (3): (3) In the formula, and are the initial lengths of the two diagonal extensometers in the measurement area, and are the deformation of the two butt-jointed extensometers, The height of the diagonal extensometer arrangement range; S6: Calculate the slip deformation ; Calculating the slip deformation includes the following steps: An extensometer is placed at the column bottom at the slip crack to measure the width of the slip crack, and then the deformation caused by slip is calculated according to formula (4): : (4) In the formula, is the slip crack width, is the horizontal distance from the sliding crack measurement point to the compression edge of the column. If there are multiple sliding cracks, the total sliding deformation is obtained by adding the sliding deformations of multiple cracks. S7: Add the calculated bending deformation, shear deformation and slip deformation to obtain the total deformation of the top of the component, compare it with the deformation measured by the laser displacement meter, and evaluate the calculation error; S8: Further calculate the proportion of each deformation component: Bending deformation ratio: Shear deformation ratio: Slip deformation ratio: 。 2. The method for analyzing the deformation of a reinforced concrete member according to claim 1, characterized in that: The reinforced concrete member is a cantilever member, a fixed end of which is anchored on the rigid ground through a ground beam, and a free end is connected to a horizontal actuator head to apply a horizontal force.

3. The method for analyzing deformation of a reinforced concrete member according to claim 1, characterized in that: The base of the reinforced concrete component is firmly connected to the rigid ground through ground anchors and hydraulic jacks.

4. The method for analyzing deformation of a reinforced concrete member according to claim 1, characterized in that: The three-dimensional non-contact optical photogrammetry system consists of a non-contact photogrammetry system, a data acquisition system and a data analysis system. The three work together to achieve real-time capture of the displacement and strain field of components during the force process.

5. The method for analyzing deformation of reinforced concrete components according to claim 1, characterized in that: Step S1: using a laser displacement meter to measure the displacement of the loading end, and using a 3D photogrammetry system to measure the displacement and deformation of the fixed end. A surface of the fixed end parallel to the loading direction is used as the observation surface, and the height of the observation area is 1.5 times the width of the observation surface. Before the specimen is loaded, the measuring surface of the specimen is first painted with matte white paint, and then the measuring area is painted with matte speckles using a speckle roller; During the speckle production process, it is necessary to ensure that the speckle size is uniform and randomly distributed, with high black and white contrast and a measurement requirement of 50% each. After the speckle production is completed, before the test begins, the three-dimensional measurement head is placed at a horizontal distance of 1.5m from the measurement surface of the specimen, and the horizontal position of the camera is fine-tuned until the speckle on the measurement surface can be clearly photographed. Then the camera is adjusted to the center height of the speckle field and the crosshairs of the left and right cameras are ensured to be in the same position. After adjusting the lighting, camera focal length and aperture size, the measurement head camera is calibrated. After the equipment is adjusted, the test begins.

6. A method for analyzing deformation of reinforced concrete components according to claim 5, characterized in that: During the test, it is set that the image acquisition is synchronized with the load and displacement test data and the same frequency is acquired.

7. The method for analyzing deformation of reinforced concrete components according to claim 1, characterized in that: The determination of the range of the plastic hinge area in step S2 is based on the strain analysis of the bottom area of ​​the specimen. At the limit state, the height of the plastic hinge is determined by using the concrete strain value on the surface of the specimen obtained by digital image correlation calculation; The area where the tensile strain of concrete at the same position on the component surface and the outermost longitudinal reinforcement is greater than 0.002 or the absolute value of the compressive strain of concrete on the component surface is greater than 0.002 is the area where plastic deformation occurs, and the height of this area is the height of the plastic hinge zone.

8. The method for analyzing deformation of reinforced concrete components according to claim 1, characterized in that: For the arrangement of measuring points for calculating bending deformation, equally spaced extensometers are arranged longitudinally at a distance of 50 mm from the left and right edges of the specimen, with a spacing of 5 cm to 10 cm between the extensometers; for the arrangement of measuring points for calculating shear deformation, two diagonal extensometers are arranged with a distance of 50 mm from the left and right edges of the specimen as the boundary; for the arrangement of measuring points for calculating slip deformation, there will be a large strain value in the direction perpendicular to the development of the crack. Therefore, the larger cracks or bottom lifting on the surface of the specimen are found according to the strain diagram, and then the horizontal cracks or bottom lifting that cause the positive and reverse slip of the specimen are judged in combination with the test record photos, and the extensometers perpendicular to them are arranged respectively.

9. The method for analyzing deformation of reinforced concrete components according to claim 1, characterized in that: The sum of the bending deformation, shear deformation and sliding deformation obtained by digital image correlation technology is compared with the reading of the laser displacement meter, and the error is controlled within 5%, and then the proportion of each deformation component is further calculated; in order to obtain a more accurate total displacement, it is necessary to arrange speckles on the ground beam to monitor the horizontal displacement during loading, and compare the horizontal displacement of the ground beam with the sum of the above three deformations and the degree of the laser displacement meter.

Images