Test method and system for evaluating crack resistance of steel bridge deck pavement concrete

Abstract

The present application relates to the technical field of concrete performance analysis, in particular to a steel bridge deck pavement concrete crack resistance performance evaluation test method and system, comprising: deriving the correction area of each crack data based on the location of the crack data; obtaining the convergence position under the current crack driving development, and identifying the crack propagation position based on the connected domain of the convergence position; based on the distribution position of the crack propagation position, taking the boundary condition of the crack propagation position as the guide, identifying the area mark and the maximum connected area of the crack propagation position, and constructing the crack network topology relationship; inferring the displacement change of each crack propagation position at multiple times, judging the connected domain formation probability of the crack propagation position based on the displacement change of each crack propagation position; based on the connected domain formation probability of the crack propagation position, the crack distribution is divided layer by layer, and stored as the crack distribution characteristics. The maintenance efficiency and paving effect of the steel bridge deck pavement layer are realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of concrete performance analysis, in particular to a steel bridge deck pavement concrete crack resistance performance evaluation test method and system. BACKGROUND

[0002] Under the background of the continuous improvement of the quality requirements of construction engineering, as a common building material, the crack resistance performance of concrete is particularly important in engineering practice. Concrete is affected by various factors during use, such as temperature change, load action, material performance, etc. These factors lead to the generation and expansion of concrete cracks, and further affect the structural integrity and service life of the building. The traditional technical scheme lacks modeling of the dynamic expansion process of cracks, which makes it difficult to predict the evolution path of cracks in concrete in the scene of steel bridge deck pavement concrete.

[0003] For example, Chinese patent publication CN115901447A discloses a full-graded concrete performance curve acquisition method, device, equipment and storage medium. The method comprises: based on the stress state of the full-graded concrete to be tested, designing the structure of the full-graded concrete test piece and the connecting device, and respectively carrying out uniaxial tensile test and uniaxial compression test to obtain the corresponding displacement and load peak value; respectively based on the displacement and load peak value, linear difference is carried out to obtain a plurality of tension-compression conversion points and compression-tension conversion points; based on the tensile loading rate, the tensile load of the test piece at each tension-compression conversion point is adjusted, and based on the compression loading rate, the compression load of the test piece at each compression-tension conversion point is adjusted; the first deformation corresponding to the tensile load and the second deformation corresponding to the compression load are collected, and fitting is carried out to obtain the full-graded concrete performance curve.

[0004] For example, Chinese patent publication CN119147740A discloses a concrete crack resistance performance simulation monitoring method, device, equipment and storage medium. The method comprises the following steps: acquiring a plurality of groups of internal microstructure images; performing different component region segmentation on the plurality of groups of internal microstructure images, and performing mechanism structure quantitative analysis to generate mechanism structure parameters of different regions; based on a plurality of sensor nodes, real-time environmental parameter monitoring is performed on the concrete to be monitored to obtain concrete environmental perception parameters; environmental stress load mining is performed on the concrete environmental perception parameters to generate concrete environmental stress load characteristics; based on the mechanism structure parameters of different regions, multi-frequency filtering noise reduction is performed on the internal three-dimensional microstructure image, and region structure three-dimensional point cloud modeling is performed to construct a concrete three-dimensional point cloud model.

[0005] The prior art respectively illustrates the performance of the concrete by the deformation amount of the concrete under the pressure load, and the defect positioning is performed on the stress evolution curve to illustrate the performance of the concrete in resisting cracks; however, the prior art ignores the crack change of the concrete in the processing process, so that the performance of the concrete in resisting cracks is too one-sided, the crack evolution trend of the concrete in a long-time advancing scene cannot be coped with, and the efficiency of the maintenance and processing of the steel bridge deck pavement concrete is reduced. SUMMARY

[0006] In order to solve the above technical problems, the technical scheme adopted by the present application is: a steel bridge deck pavement concrete crack resistance performance evaluation test method, comprising: S1, based on the crack data to be obtained, setting a crack grid map at the position of the crack data, and deriving a correction area of each crack data.

[0007] S2, obtaining the convergence position under the current crack driving development according to the passing cost and passing risk of the correction area, and identifying the crack expansion position according to the connected domain of the convergence position.

[0008] S3, based on the distribution position of the crack expansion position, identifying the area mark and the maximum connected area of the crack expansion position according to the boundary condition of the crack expansion position, and constructing the crack network topology relationship.

[0009] S4, based on the value of the crack network topology relationship in multiple time periods, inferring the displacement change amount of each crack expansion position at multiple time points, and judging the connected domain formation probability of the crack expansion position based on the displacement change amount of each crack expansion position.

[0010] S5, based on the connected domain formation probability of the crack expansion position, layer-by-layer dividing the crack distribution, and storing as a crack distribution feature.

[0011] A steel bridge deck pavement concrete crack resistance performance evaluation test system, comprising: a crack data acquisition module, configured to set a crack grid map at the position of crack data to be obtained based on the crack data to be obtained, and derive a correction area of each crack data.

[0012] A connected domain identification module is configured to obtain the convergence position under the current crack driving development according to the passing cost and passing risk of the correction area, and identify the crack expansion position according to the connected domain of the convergence position.

[0013] A topology construction module is configured to identify the area mark and the maximum connected area of the crack expansion position according to the boundary condition of the crack expansion position based on the distribution position of the crack expansion position, and construct the crack network topology relationship.

[0014] The probability identification module is configured to infer displacement change amounts of each crack propagation position at multiple time points based on values of the crack network topological relationship at multiple time periods, and determine a connected domain formation probability of the crack propagation position based on the displacement change amounts of each crack propagation position.

[0015] The feature storage module is configured to divide the crack distribution layer by layer based on the connected domain formation probability of the crack propagation position, and store the crack distribution features.

[0016] The present application has the following advantages: 1. The present application generates a grid map based on a set of crack coordinate points, sets a basic correction region in combination with a distribution density constraint, and adjusts the correction region using directional derivative clustering and superposition azimuth matching to solve the problem of initial positioning error caused by crack data interference in the traditional processing process, thereby improving the accuracy of crack identification. Then, the area ratio and migration probability are used to calculate the convergence position probability to introduce the shortest path to judge the connectivity of adjacent cracks, and further identify the dominant region of each crack propagation in the fragmented cracks.

[0017] 2. The present application determines the topological stability based on the maximum connected area addition rule, and determines the target topological relationship by using the closed target region to determine the connected path of crack propagation, quantitatively describes the crack branch relationship, and calculates the connected domain formation probability in combination with the cumulative effect of displacement change amount and conditional probability to describe the crack propagation path in the form of probability value, thereby further showing the trend of crack propagation.

[0018] 3. The present application divides the storage subspaces by space-time index, and adds double identification codes to update the current crack distribution features in real time to analyze the anti-cracking performance of steel bridge deck pavement concrete under crack propagation, and provides data basis for bridge deck maintenance. BRIEF DESCRIPTION OF DRAWINGS

[0019] The present application will be further described below in combination with the drawings and examples.

[0020] Figure 1 It is a flowchart of a steel bridge deck pavement concrete anti-cracking performance evaluation test method.

[0021] Figure 2 It is a flowchart of step S1 of a steel bridge deck pavement concrete anti-cracking performance evaluation test method.

[0022] Figure 3 It is a flowchart of step S2 of a steel bridge deck pavement concrete anti-cracking performance evaluation test method.

[0023] Figure 4 It is a flowchart of step S3 of a steel bridge deck pavement concrete anti-cracking performance evaluation test method.

[0024] Figure 5 is a flowchart of step S4 of the method for evaluating the crack resistance of steel bridge deck pavement concrete.

[0025] Figure 6 is a flowchart of step S5 of the method for evaluating the crack resistance of steel bridge deck pavement concrete.

[0026] Figure 7 is a system diagram of the system for evaluating the crack resistance of steel bridge deck pavement concrete. DETAILED DESCRIPTION

[0027] Embodiments of the present application will be described in detail below. The embodiments described below are exemplary and are intended to explain the present application, and should not be construed as limiting the present application. If a specific technique or condition is not mentioned in the embodiments, the technique or condition described in the literature in the art or according to the product manual is used.

[0028] Referring to Figure 1 A method for evaluating the crack resistance of steel bridge deck pavement concrete, comprising: S1, based on the crack data to be obtained, setting a crack grid map at the location of the crack data, and deriving a correction area of each crack data.

[0029] S2, obtaining the convergence position under the current crack driving development based on the passing cost and passing risk of the correction area, and identifying the crack propagation position based on the connected domain of the convergence position.

[0030] S3, based on the distribution position of the crack propagation position, identifying the area mark and the maximum connected area of the crack propagation position based on the boundary condition of the crack propagation position, and constructing the crack network topology relationship.

[0031] S4, based on the values of the crack network topology relationship at multiple time periods, inferring the displacement change amount of each crack propagation position at multiple time points based on the collection constraint of the current crack data, and judging the connected domain formation probability of the crack propagation position based on the displacement change amount of each crack propagation position.

[0032] S5, based on the connected domain formation probability of the crack propagation position, layer-by-layer dividing the crack distribution, and storing it as a crack distribution feature.

[0033] The crack data described above includes crack length, crack shape, crack position, crack width, crack area, crack density, and the like of the concrete, and these data can be scanned by image acquisition from the currently set concrete, and by observing the area where the concrete crack development and convergence are achieved, the obvious defects and risks existing under the crack development can be identified.

[0034] In step S1, when the modified region of each crack data is derived, the crack data collected at a certain time is taken as the initial crack, and the local position where the crack may appear is taken as the part of focus, which is recorded as the modified region in the current description. It should be noted that step S1 takes the time period when the stable crack appears as the basis, and after observing the size, distribution density and other values of each crack over time under the formation of stable cracks, the region that needs to be observed at present is selected.

[0035] At this time, the use scenario can be direct tension, ring constraint, flat plate shrinkage crack, four-point bending and other test methods during concrete test, so as to measure the probability and size of cracks at each position of concrete under constant load.

[0036] As shown in Figure 2 The implementation of step S1 includes: S11, loading the coordinate point set corresponding to the crack data, setting the crack grid graph according to the crack direction angle and the crack endpoint coordinates.

[0037] S12, according to the distribution density and distribution range constraint of each crack in the crack grid graph, setting the basic modified region according to the shape of the crack combination.

[0038] S13, introducing the direction derivative and superposition direction of each crack, merging and modifying the corresponding crack in the basic modified region, and outputting the modified crack data as the modified region.

[0039] Preferably, the implementation of step S12 further includes: taking the distribution range constraint of each crack in the crack grid graph as the basis, identifying the cracks under different distribution range constraints, and judging the distribution density of the grid where each crack is located according to the shape of the crack combination. When the distribution density of the grid where the crack is located is greater than the preset density threshold, the corresponding grid is regarded as the output basic modified region.

[0040] Preferably, the preset density threshold is set to the kernel density estimation value calculated for each grid when the obvious crack appears in the historical data, which is taken as the current preset density threshold. At this time, the calculated value needs to take the data corresponding to the same material and the same load condition at the current test as the basis for comparison.

[0041] Preferably, when identifying the distribution density of each crack, the kernel density estimation calculation method is used to derive the bandwidth of the current kernel density calculation from the average error calculated by the adjacent tests in the historical data, and then the distribution density of each crack in the crack grid map is calculated based on the currently identified crack endpoint coordinates; and the distribution range of the crack is described according to the crack endpoint coordinates, and then the coordinates of the current distribution range are regarded as the distribution range constraint to describe the shape of the crack combination; at this time, the distribution range constraint of the crack will be further set as the constraint on the size of the crack, the constraint on the distance between the crack endpoints, and the constraint on the angle of the crack; that is, whether the size of the plurality of cracks is smaller than the preset crack size, whether the distance between adjacent cracks is smaller than the preset interval distance, and whether the angle between adjacent cracks is close; the distribution density of the crack is obtained in the form of combining or removing a plurality of cracks according to the distribution range of the currently identified crack, and a plurality of regions are obtained based on the value of the distribution density.

[0042] For example, according to the crack endpoint coordinates, micro-cracks smaller than the preset crack size are removed, such as using 0.1 mm as the preset crack size, and after removing the micro-cracks; the part of the crack in the current crack that has an angle deviation smaller than the preset angle deviation and an endpoint distance smaller than the preset interval distance is merged, a plurality of cracks that can be directly connected are combined, the shape of the crack combination is described, and these combined cracks are marked according to the corresponding distribution range constraint, then all the cracks are traversed, and according to the local kernel density of the corresponding crack in the divided grid, a plurality of regions are divided, which represent the relative density of the crack distribution.

[0043] As for the above-mentioned preset angle deviation, it can be set based on historical data, such as using 15° as the current preset angle deviation, and the preset interval distance can be 2 mm to connect a plurality of cracks that have a direct connection relationship.

[0044] Preferably, when introducing the directional derivative of each crack, the directional derivative is calculated by calculating the derivative of the rate of change of the angle of the plurality of cracks in the current basic correction region with respect to time, to describe the trend of the plurality of cracks in the current basic correction region; and the superposition direction is to judge the projection of the plurality of cracks on the coordinate system, such as sequentially dividing into the types of crack projection intersection, such as same direction parallel, opposite direction parallel, orthogonal intersection and oblique intersection, and regarding a plurality of cracks having the corresponding type as the same correction region according to these types, to describe the position that needs to be focused on.

[0045] The derivative of the fracture trend angle change rate in multiple time periods is taken as the direction derivative, and the fractures in each foundation correction region are clustered. At this time, the clustering method uses the DBSCAN or K-means algorithm, and the fracture trend angle change rate is taken as the main content. The change trend of multiple groups of fractures in multiple time periods is viewed, and the classification of the superposition direction between the fractures is installed for multi-condition classification, so as to complete the classification processing of related fracture data.

[0046] Preferably, the implementation mode of step S13 comprises: S131, taking the direction derivative of each fracture as a trend label, performing hierarchical clustering on each fracture in the foundation correction region to obtain a plurality of clustered clusters; the trend label is used to indicate a label indicating the fracture expansion state such as stable, rapid expansion, slow expansion, etc.

[0047] S132, according to the superposition direction of each fracture in the same cluster, performing direction matching on each fracture, and adjusting the foundation correction region based on the direction matching result, and taking the adjusted region as the output correction region.

[0048] Preferably, when performing direction matching, the current fracture is projected in a horizontal and vertical axis or a 45-degree oblique manner, and it is judged whether the projected fracture exists in the same direction parallel, reverse parallel, orthogonal intersection and oblique intersection, if not, the original region is taken as the output correction region, and the clustered data marked by the direction derivative is taken as the output correction region; if so, the fracture corresponding to the same direction parallel and orthogonal intersection is output in the form of the minimum enclosing circle; for reverse parallel and oblique intersection, the main fracture direction is extended, and the region corresponding to the extended fracture is taken as the output correction region. The extension distance can be extended based on half of the length of the original main fracture direction. If the extended distance also contains other fractures, the minimum enclosing convex hull containing other fractures and the current reverse parallel and oblique intersection related fractures is output.

[0049] In one embodiment of the present application, as shown in Figure 3 The implementation mode of step S2 comprises: S21, fracture feature extraction is performed on each fracture in the correction region, the actual area ratio of each fracture is set as the passing cost, the state transition probability of each fracture is set as the passing risk, and the distribution probability of the convergence position in each fracture is calculated.

[0050] S22, whether there is a connected domain between each convergence position is judged according to the distribution probability of the convergence position, if there is, the fracture expansion position is set according to the area ratio of the connected domain; if not, the center position of the combination of multiple convergence positions is set as the fracture expansion position.

[0051] The convergent position mentioned above represents a region where the standard deviation of the crack area is less than 1% in a continuous time period, and whether there is a relatively stable local crack position in the grid corresponding to the current correction region is identified based on the plurality of grids divided by the crack grid map.

[0052] Preferably, the actual damage amount mentioned above represents the ratio of the area value of each crack to the current correction region, which is used to indicate the size of the current crack growth over time; and the state transition probability represents the probability value of the crack expansion to the adjacent coordinate point under the plurality of time changes, and the probability value of the current crack expansion to the adjacent position is used as the risk of passing through, and the transition probability can be obtained by checking the frequency of the current crack expansion to the adjacent position in the historical data, and the value of the current transition probability is indicated by the ratio of the total frequency.

[0053] Preferably, when calculating the state transition probability, the coordinates of the adjacent spatial positions are viewed based on the coordinates of the current processing convergent position, for example, a viewing range of 5mm is used to calculate the state transition probability of the plurality of coordinate points in the current crack, and then the relative situation of the current convergent position is determined.

[0054] Preferably, the connected domain mentioned above is used to indicate whether there is a directly connected region between the convergent positions of the plurality of cracks after the convergent positions reach a stable state, and this part of the region represents a continuous fracture region, or a region that may soon complete the fracture connection after obvious fracture, which indicates the extension of the crack during expansion.

[0055] Preferably, when the distribution probability of the convergent position is calculated in step S21, the actual area ratio of the crack where the current convergent position is located and the state transition probability are used to set the conditional probability of the current convergent position to meet the conditional probability value of the two conditions, which is used to indicate the probability of the current convergent position appearing in multiple tests; and the state transition probability is set based on the coordinates of the edge of each crack, and is labeled as expanded and unexpanded, which indicates the state transition probability of each crack edge completing expansion under the corresponding time period, and then the convergent position that has been diffused and is located in the crack is used to represent the probability value that different crack convergences can achieve.

[0056] Preferably, the implementation manner of step S22 further includes: when the identified connected domain is located in the crack, the adjacent region of the convergent position is used for multi-crack position checking, and the continuous region of the plurality of cracks is regarded as the connected domain of the convergent position.

[0057] When the identified connected domain is located between adjacent cracks, the distance between the convergence position and the adjacent cracks is determined, and when the distance between the adjacent cracks is less than the preset crack distance, the shortest path between the convergence positions of the multiple cracks is regarded as the connected domain of the convergence position. At this time, the preset crack distance represents the average value of the minimum distance between the multiple cracks during crack propagation, and when the average value is processed based on multiple time periods, the average value of the minimum distance between the cracks in the modified region is divided.

[0058] When the connected domain is located in the crack, the convergence position is inside the crack, and at this time, a verification region with a radius of 3-5 times the crack width is expanded around the convergence position. The spatial continuity of all crack segments in the verification region is detected, and when the crack segment spacing is ≤2 times the crack width, it is determined as a continuous region.

[0059] The area of the connected domain is equal to the area of the continuous crack segment plus the area of the bridging region between the cracks. The bridging region is a triangular filling region of the crack gap. The triangle is the smallest orthogonal triangle in the middle of the continuous crack gap. Even if the two cracks reach the smallest triangle after intersection, the area value is represented by the product of the pixel point count and the actual area of a unit pixel in the continuous crack segment area to represent the area of the corresponding connected domain.

[0060] When the connected domain is located between adjacent cracks, the convergence position is between the cracks, and at this time, the average value of the minimum distance between the cracks in each time period in the modified region is taken as the preset crack distance. When there is a crack spacing less than the preset crack distance, the shortest path between the convergence positions along the crack direction is calculated, and a strip-shaped connected domain is constructed with the path as the center line. The strip width of the strip-shaped region is equal to the average crack width plus the spacing compensation value. Here, the average crack width represents the average width value of the adjacent cracks, and the spacing compensation value is set based on the pressure and load during the current experiment. This value can be adjusted based on the experimental conditions and configured in the database.

[0061] The area of the connected domain is equal to the shortest path between the convergence positions along the crack direction multiplied by the strip width. At this time, it is also described based on the pixel point count and the actual area of a unit pixel.

[0062] Preferably, the spacing compensation value is set based on the relative error of the crack area in the continuous time period. The percentage value of the crack area error in the continuous time period is used to set the spacing compensation value, which is equal to the average crack width multiplied by the corresponding percentage value to complete the relative adjustment of crack identification.

[0063] In the processing process of the current step, the connected domains inside and between the cracks are mainly distinguished to avoid misjudgment caused by fractures, holes or noise. The preset crack distance and the spacing compensation value are used to adapt to the crack evolution law under different materials, stresses or time scales.

[0064] In one embodiment of the present invention, region markers are used to identify connected domains at the location of crack propagation and to label their boundaries and geometric features, such as area and centroid; the maximum connected area is used to determine the region with the largest area among all connected domains, which serves as the core part of the crack network; topological relationships are used to construct the graph structure of the crack network based on the spatial connection relationships between regions, such as contact and intersection, to form a network relationship for multiple crack propagation.

[0065] The boundary conditions, used to describe the region boundary where the current crack propagation location is situated, and the relative label of that region, include not only the region label and the data for the maximum connected area, but also the width and length of multiple cracks when determining the crack propagation location. Additionally, the boundary conditions can include the load received at the current crack location to illustrate the differences in crack propagation under different load conditions.

[0066] When constructing the topology of a crack network, the current crack expansion location can be combined in a multi-dimensional manner using nodes, edges, surfaces, and volumes. For example, when using nodes as topological connections, the intersection or endpoint of the crack expansion location is used as the starting point to connect multiple crack expansion locations. When using edges as topological connections, the crack line segments at the crack expansion location are used to perform multi-segment fitting to illustrate the crack network topology. When using surfaces as topological connections, multiple closed crack surfaces are connected using closed crack loops at the crack expansion location. In this case, multiple crack surfaces can overlap or the mapping relationship can be expressed using line segments to form the crack network topology. When using volumes as topological connections, the three-dimensional connected domain of each crack expansion location is used as the main content, and the association between multiple crack expansion locations is illustrated using three-dimensional overlap or multiple layers.

[0067] like Figure 4 As shown, the implementation of step S3 includes: S31, in response to the connected domains corresponding to the crack expansion location, the maximum connected area of ​​each connected domain is used to add the connected domains together to determine the area value after addition in the current time period.

[0068] S32, when the change in area value after adding the current time intervals is less than the change in area value obtained last time, the topological relationship of each crack expansion position in the continuous scanning scene is determined based on the connection relationship of the current crack expansion position. When the topological relationship of the crack expansion position is the target topological relationship, the current topological relationship is used as the output crack network topological relationship.

[0069] In step S3, the connected domain processing manner of step S3 is based on the connected domain described in step S2, compares the rate of crack area expansion under crack expansion, describes the law and area size of crack propagation of the current concrete under the corresponding experimental conditions, and finally realizes the identification of the anti-cracking performance of the current concrete bridge deck paving scene.

[0070] The implementation manner of the target topological relationship in step S32 includes: marking the area along the crack propagation position, taking the boundary condition when the crack propagation positions are connected as the first limit value, and taking the maximum connected area of the crack propagation position as the second limit value.

[0071] Using the first limit value and the second limit value, a closed target area is formed, and the crack propagation position is reconstructed based on the closed target area. The topological relationship on the reconstructed crack propagation position is the target topological relationship.

[0072] Preferably, the boundary condition is used to record the distance between different connected domains, the stress intensity received at the corresponding position, and the like. When the boundary condition is taken as the first limit value, the crack edge marked by the area mark along the corresponding crack propagation position is used to indicate the boundary of the current crack propagation. The first limit value can extract the crack edge based on Canny edge detection or morphological gradient. As for the second limit value, the connected domain with the largest area identified in the current time period is taken as the dominant area to ensure that the crack main body is completely covered, and the corresponding area is regarded as the content contained in the second limit value. Then, starting from the boundary of the crack propagation corresponding to the first limit value, the pixel is expanded, and the maximum connected area is taken as the constraint to ensure that the area is closed, and the closed crack area is indicated. Thereafter, the line segment and the like of the crack connection on the crack area are taken as the output target topological relationship, which is used to further segment the crack area, retain the relative area under the crack propagation and stretching, ensure that the current crack propagation identification is located in the main structure, and ensure that the reconstructed crack has no discontinuity or error branch in the geometric path.

[0073] When reconstructing the crack propagation position, the initial seed point is determined based on the crack edge in the first limit value, the region is grown, and the maximum connected area of the second limit value is used to retain only the area with the largest area as the dominant crack in all connected domains. The corresponding area is re-grown to obtain the output closed target area.

[0074] Preferably, the difference average value of the pixel value at the crack propagation position is obtained as the main condition, only the points in the adjacent area of the crack propagation position with a pixel value less than the difference average value are allowed to be merged, that is, the value of the pixel point in the neighborhood is less than the difference average value after the value is subtracted from the average value, then the corresponding region is merged, and after the region corresponding to the first limit value is retained only in the part describing the maximum connected area, if there is a problem of initial boundary discontinuity in the connected region, the difference average value is set as the maximum one of the difference average values obtained in the multiple seed points, and the judgment value of the region generation is set. If there are branches when the crack is divided in the region where the second limit value is located, the maximum connected domain may only retain the main branch; at this time, the pixel points consistent with the first limit value are preferentially merged, and morphological closing operation is performed according to the region where the second limit value is located, and the missing points are connected in the form of morphological supplement. If the crack edge spreads to both sides during expansion, the region where the first limit value and the second limit value is located needs to be identified, the main expansion position of the crack is identified, and the closed target region of the current cutting is retained only in the region with consistent area change gradient, to illustrate the size and relative area of the main region during crack expansion.

[0075] As for the constructed crack network topological relationship, the main region of the crack during expansion and the area, connection mode, shape and other contents between multiple regions during crack expansion are emphasized, the main regions of multiple crack expansions are displayed in the form of topological relationship, so as to describe the current concrete crack resistance.

[0076] In an embodiment of the present application, the connected domain formation probability of the current crack data is used to represent the current data processing in a conditional loop, to identify the displacement change amount generated at the corresponding crack propagation position, so as to identify the crack resistance and propagation form of the crack under multiple constant loads.

[0077] For example, according to the value of the crack network topological relationship in multiple time periods, the crack propagation position is divided into different regions such as high defect area, low defect area, fast convergence area and slow convergence area, then the connected domain formation probability is related to the cumulative effect of crack propagation, a probability model related to the area of connected domain is constructed by integrating the crack propagation rate in the form of probability density function, to illustrate the scale of crack propagation and the elongation degree of crack under the condition of main crack propagation, and finally to illustrate the continuous development of the crack network, and finally to deduce whether the concrete crack resistance meets the requirements under the corresponding bridge deck scene.

[0078] For example, according to the value of the crack network topological relationship in multiple time periods, the crack propagation position is divided into different regions such as high defect area, low defect area, fast convergence area and slow convergence area, then the connected domain formation probability is related to the cumulative effect of crack propagation, a probability model related to the area of connected domain is constructed by integrating the crack propagation rate in the form of probability density function, to illustrate the scale of crack propagation and the elongation degree of crack under the condition of main crack propagation, and finally to illustrate the continuous development of the crack network, and finally to deduce whether the concrete crack resistance meets the requirements under the corresponding bridge deck scene. Figure 5As shown, the implementation of step S4 includes: S41, taking the time period in which the crack network topological relationship crack propagation position appears data changes as the starting point, tracking each crack propagation position, and obtaining the displacement change amount of each crack propagation position based on the length of the crack propagation position after expansion.

[0079] S42, based on the cumulative effect of the displacement change amount, associating the displacement change amount with the crack propagation position, and regarding the conditional probability of each crack propagation position after association as the connected domain formation probability of the crack propagation position.

[0080] At this time, the probability model is constructed by the maximum connected area of the displacement change amount and the crack propagation position, and the probability value of the crack propagation position under the lognormal distribution is obtained based on the output result of the probability model, and the crack propagation position of the adjacent region is introduced based on the probability value, to obtain the conditional probability of each crack propagation position relative to the neighborhood. This conditional probability will indicate the change probability of the main expansion area of the crack propagation, to explain the corresponding growth of the connected domain under the change of time period. If the probability value is large, it indicates that the connectivity of the crack propagation position is high, and there is a significant crack propagation trend, which may correspond to a high defect area or a fast convergence area; if the probability value is small, it indicates that the connectivity of the crack propagation area is low, and the crack propagation possibility is small, which may correspond to a low defect area or a slow convergence area, to restrictively explain the crack propagation situation.

[0081] Assuming that the number of load cycles under the current test scenario is known, and the material constant of the corresponding experimental concrete is known, the displacement change amount can be described using the content included in Price's law in the form of integral.

[0082] As the displacement change amount is represented as: ; represents the displacement change amount, which is used to describe the length value of the corresponding crack during expansion. The displacement change amount is obtained by identifying the length values of multiple equidistant identifications on the maximum connected area of the main expansion, to describe the cumulative effect of crack propagation. These contents will be differentiated and integrated to determine the change rate of crack propagation; represents the number of load cycles, which describes the number of load cycles of the concrete in the current time period, and indirectly describes the time length of the crack change of the concrete; and both represent material constants, but is a constant that describes the basic displacement change amount of crack propagation under fatigue load, is a constant for the value of the stress intensity factor amplitude. These two constants will describe the material constants of the concrete being measured based on three-point bending tests, compact tension tests, etc. This part of the area will be directly labeled in the database; The stress intensity factor amplitude is represented, and the amplitude is directly obtained by the stress applied in the experiment to determine the direct stress value of the current concrete when cracking.

[0083] When judging the formation probability of the connected domain related to the cumulative effect of crack propagation, the area of the connected domain at the marked crack propagation position is determined by the cumulative value of the displacement change amount at this time.

[0084] The characteristic value of the connected domain area related to the crack propagation position at this time is represented as shown below.

[0085] ; wherein, The characteristic value of the connected domain area related to the crack propagation position is used to further describe the growth of the connected domain at the crack propagation position using the cumulative effect; and The upper and lower limit values of the displacement change amount respectively represent the multiple length values of the identification of the current single crack propagation position, and the displacement change amount identified here is the continuous displacement value extracted at intervals of one-fifth or less of the original crack width to the expanded region based on the original region, to explain the current crack propagation.

[0086] After the extracted characteristic value satisfies the lognormal distribution and the probability value is determined, the corresponding value condition is obtained, for example, in the form of Gaussian distribution, the logarithm of the characteristic value related to the current connected domain area is taken as the input, and after the probability value of each crack propagation position is calculated, when the crack propagation position of the neighborhood is introduced, the related area values in the two regions are calculated by the calculation formula of the probability value in the Gaussian distribution, to calculate the joint probability of the two regions, and complete the calculation of the conditional probability of the current crack propagation position.

[0087] In an embodiment of the present application, in step S5, based on the connected domain formation probability, the crack propagation situation is synchronized to the corresponding data under the current test conditions, and the identified crack distribution characteristics are stored in the form of hierarchical division according to the multiple connected domains of the current crack propagation.

[0088] As Figure 6 shown, the implementation of step S5 includes: S51, based on the input connected domain formation probability, the storage space is divided into multiple storage subspaces; and the crack propagation position is divided layer by layer in each storage subspace.

[0089] At this time, the space index represents the center coordinates of the crack corresponding position, and the multiple coordinates representing the crack end points; and the time index represents the start point and end point of the time period of the crack propagation position in the experimental scene.

[0090] S52, with the logical structure of each level in the hierarchical storage, the crack propagation position corresponding data is divided, and each part of the data is taken as a first identification code when the division, and the additional information is taken as a second identification code when the division exists.

[0091] S53, when the first identification code and the second identification code correspond in each storage subspace, the corresponding data is stored in the corresponding storage subspace, and when the second identification code does not exist, the corresponding data is regarded as the output crack distribution characteristics.

[0092] In the above description, the spatial index and the time index are taken as the first identification code for identification, the first identification code is mainly divided level by level based on the area where the coordinates are located when marking, and the time is divided level by level based on the order of the time period; the second identification code is used to explain the probability value, the topological relationship and the other cracks connected by the current crack; when the second identification code exists, the data of the two identification codes are combined to store the distribution characteristics of the crack when it expands; when the second identification code information does not exist, it generally represents that the current data is in the form of temporary storage data, or it represents the data for updating the crack distribution, and it is not necessary to check the probability value and the topological relationship corresponding to the crack and other data, at this time, the relevant data is stored to obtain the distribution of the cracks of the concrete in the concrete anti-cracking performance experiment, which is convenient for checking the relative situation of the bridge deck pavement concrete in the future.

[0093] As shown in Figure 7 , the application also provides a steel bridge deck pavement concrete anti-cracking performance evaluation test system, which comprises a crack data acquisition module, a connected domain identification module, a topological construction module, a probability identification module and a feature storage module; wherein the output end of the crack data acquisition module is connected with the connected domain identification module, the output end of the connected domain identification module is connected with the topological construction module, the output end of the topological construction module is connected with the probability identification module, and the output end of the probability identification module is connected with the feature storage module.

[0094] The crack data acquisition module is used for setting a crack grid based on the to-be-acquired crack data and the position of the crack data, and deducing a correction area of each crack data.

[0095] The connected domain identification module is used for acquiring a convergence position under the development of the current crack based on the passing cost and the passing risk of the correction area, and identifying the crack propagation position based on the connected domain of the convergence position.

[0096] The topological construction module is used for identifying the area mark and the maximum connected area of the crack propagation position based on the distribution position of the crack propagation position and the boundary condition of the crack propagation position as a guide, and constructing the topological relationship of the crack network.

[0097] The probability identification module is configured to infer displacement change amounts of the crack propagation positions at multiple time points based on values of the crack network topological relationship at multiple time periods, and determine a connected domain formation probability of the crack propagation positions based on the displacement change amounts of the crack propagation positions.

[0098] The feature storage module is configured to divide the crack distribution layer by layer based on the connected domain formation probability of the crack propagation positions, and store the crack distribution features.

[0099] Although the embodiments of the present application have been shown and described above, it should be understood that the above embodiments are exemplary and should not be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application, which are still covered by the protection scope of the present application.

Claims

1. A test method for evaluating the crack resistance of concrete pavement on steel bridge decks, characterized in that, include: S1, Based on the crack data to be acquired, set a crack mesh diagram according to the location of the crack data, and derive the correction area of ​​each crack data. S2, by adjusting the passage cost and passage risk of the correction area, obtains the convergence position under the current crack-driven development, and identifies the crack expansion position by the connected domain of the convergence position; The implementation of step S2 includes: S21, extracting crack features for each crack in the correction area, setting the passage cost based on the actual area ratio of each crack, setting the passage risk based on the state transition probability of each crack, and calculating the distribution probability of the convergence position in each crack. S22, based on the distribution probability of the convergence positions, determine whether there is a connected region between each convergence position. If there is, set the crack propagation position according to the area ratio of the connected region; if not, set the crack propagation position according to the center position of the combination of multiple convergence positions. S3, based on the distribution of crack propagation locations and guided by the boundary conditions of crack propagation locations, identifies the regional markers and maximum connected area of ​​crack propagation locations, and constructs the crack network topology. S4. Based on the values ​​of the crack network topology over multiple time periods, infer the displacement changes at each crack propagation location at multiple time periods. Based on the displacement changes at each crack propagation location, determine the probability of connected component formation at the crack propagation location. S5, based on the probability of connected components forming at the crack propagation location, divides the crack distribution layer by layer and stores it as crack distribution features.

2. The test method for evaluating the crack resistance of concrete pavement on steel bridges according to claim 1, characterized in that, The implementation methods for step S1 include: S11, Load the coordinate point set corresponding to the crack data, and set the crack mesh diagram with the crack direction angle and crack endpoint coordinates. S12, Based on the distribution density and distribution range constraints of each crack in the crack mesh diagram, the basic correction area is set according to the shape of the crack combination; S13: Import the directional derivatives and superposition orientations of each crack, merge and correct the corresponding cracks in the base correction area, and output the corrected crack data as the correction area.

3. The test method for evaluating the crack resistance of steel bridge deck concrete pavement according to claim 2, characterized in that, The implementation methods of step S13 include: S131, using the directional derivative of each crack as a trend label, hierarchical clustering is performed on each crack in the basic correction region to obtain multiple clusters; the trend label is a label used to represent the crack propagation state. S132, based on the superposition orientation of each crack under the same cluster, perform orientation matching on each crack, adjust the basic correction region based on the orientation matching result, and regard the adjusted region as the output correction region.

4. The test method for evaluating the crack resistance of concrete pavement on steel bridges according to claim 1, characterized in that, The implementation of step S22 also includes: When the identified connected region is located within a crack, multiple crack locations are checked using regions adjacent to the convergence location, and continuous regions of multiple cracks are considered as connected regions of the convergence location. When the identified connected component is located between adjacent cracks, the distance between the convergence position and the adjacent cracks is determined. When the distance between adjacent cracks is less than the preset crack distance, the shortest path between each convergence position among multiple cracks is regarded as the connected component of the convergence position.

5. The test method for evaluating the crack resistance of concrete pavement on steel bridges according to claim 1, characterized in that, Step S3 can be implemented in the following ways: S31, in response to the connected components corresponding to the crack propagation location, sum the connected components by the maximum connected area of ​​each component to determine the summed area value for the current time period; S32, when the change in area value after adding the current time intervals is less than the change in area value obtained last time, the topological relationship of each crack expansion position in the continuous scanning scene is determined based on the connection relationship of the current crack expansion position. When the topological relationship of the crack expansion position is the target topological relationship, the current topological relationship is used as the output crack network topological relationship.

6. The test method for evaluating the crack resistance of steel bridge deck concrete pavement according to claim 5, characterized in that, The implementation methods of the target topological relationship in step S32 include: The region along the crack propagation location is marked, with the boundary condition at the crack propagation location as the first limit value and the guide of the maximum connected area at the crack propagation location as the second limit value. Using the first and second boundary values, a closed target region is formed. The crack propagation location is reconstructed using the closed target region, and the topological relationship at the reconstructed crack propagation location is taken as the target topological relationship.

7. The test method for evaluating the crack resistance of concrete pavement on steel bridges according to claim 1, characterized in that, Step S4 can be implemented in the following ways: S41, taking the time period when the crack propagation position in the crack network topology changes as the starting point, track each crack propagation position, and obtain the displacement change of each crack propagation position based on the crack length after propagation. S42, based on the cumulative effect of displacement change, the displacement change is associated with the crack propagation location, and the conditional probability of each crack propagation location after association is regarded as the probability of the formation of a connected region of the crack propagation location.

8. The test method for evaluating the crack resistance of concrete pavement on steel bridges according to claim 1, characterized in that, Step S5 can be implemented in the following ways: S51, based on the probability of connected component formation in the input, the storage space is divided into multiple storage subspaces; the crack propagation location is divided layer by layer using the spatial index and temporal index in each storage subspace; S52 uses the logical structure of each layer in the hierarchical storage to divide the data corresponding to the crack expansion position, and uses the data of each part at the time of division as the first identifier code. When there is additional information at the time of division, the additional information is identified as the second identifier code. S53, when the first identifier code corresponds to the second identifier code in each storage subspace, the corresponding data is stored in the corresponding storage subspace, and when there is no second identifier code, the corresponding data is regarded as the output crack distribution characteristics.

9. A test system for evaluating the crack resistance performance of steel bridge deck concrete pavement, used to perform the steps in the test method for evaluating the crack resistance performance of steel bridge deck concrete pavement as described in any one of claims 1-8, characterized in that, include: The crack data acquisition module is used to set up a crack mesh map based on the location of the crack data to be acquired, and to deduce the correction area for each crack data. The connected component identification module is used to obtain the convergence position under the current crack propagation based on the passage cost and passage risk of the corrected area, and to identify the crack expansion position based on the connected component of the convergence position. The topology building module is used to identify the region markers and maximum connected area of ​​crack propagation locations based on the distribution of crack propagation locations and guided by the boundary conditions of crack propagation locations, and to construct the crack network topology. The probability identification module is used to infer the displacement change of each crack propagation position at multiple time points based on the values ​​of the crack network topology relationship at multiple time periods, and to determine the probability of the formation of the connected component at each crack propagation position based on the displacement change of each crack propagation position. The feature storage module is used to divide the crack distribution layer by layer based on the probability of connected components forming at the crack propagation location and store it as crack distribution features.

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