A method for calculating characteristic parameters of ribbed steel bar corrosion based on contour restoration

Abstract

The invention discloses a method, system, device and medium for calculating characteristic parameters of ribbed steel bar corrosion based on contour restoration. The method comprises the following steps: obtaining three-dimensional point cloud data of the surface contour of the corroded ribbed steel bar, performing coordinate transformation and binary interpolation processing on the three-dimensional point cloud data, and generating a corroded ribbed steel bar surface; restoring the original ribbed steel bar surface based on the time domain characteristics and frequency domain characteristics of the corroded ribbed steel bar surface; comparing the corroded ribbed steel bar surface with the original ribbed steel bar surface, and calculating the characteristic parameters of ribbed steel bar corrosion. The invention integrates the time domain information and frequency domain information of the corroded ribbed steel bar contour, restores the contour of the ribbed steel bar when it is not corroded, innovatively solves the problem of irregularity of the ribbed steel bar surface contour, and realizes accurate calculation of the characteristic parameters of ribbed steel bar corrosion.

Description

Technical Field

[0001] The present invention belongs to the technical field of reinforced concrete structure performance detection, and specifically relates to a method, system, equipment and medium for calculating characteristic parameters of ribbed steel bar corrosion based on contour restoration. Background Art

[0002] The marine environment, with its unique characteristics of high salinity, high humidity and corrosive substances, significantly accelerates the corrosion process of steel bars in reinforced concrete structures. This environmental characteristic poses a severe challenge to the safety and durability of key infrastructure such as offshore platforms, port facilities, bridges, and tunnels. In order to ensure the stability and safety of these in-service facilities in extreme weather conditions and natural disasters, regular and accurate performance evaluation is particularly important. Among them, accurate analysis of the corrosion characteristic parameters of steel bars is a key step in scientifically and rationally evaluating the actual corrosion status of steel bars, which can provide a reliable basis for formulating effective maintenance strategies, thereby ensuring the safety and stability of these structures.

[0003] In recent years, solid three-dimensional reconstruction technology represented by three-dimensional laser scanning technology has provided a powerful method for accurately measuring the complex contour shape of corroded steel bars. The existing technology still has the following problems when calculating the corrosion characteristic parameters of ribbed steel bars: (1) Contour irregularity: Due to the structural characteristics of the transverse and longitudinal ribs, the surface contour of ribbed steel bars is significantly irregular, which directly affects the accurate calculation of characteristic parameters. (2) Data loss: There is a general lack of three-dimensional scanning data of uncorroded ribbed steel bars. Traditional methods usually simplify ribbed steel bars into plain round steel bars for calculation, ignoring the influence of transverse and longitudinal ribs on local corrosion efficiency. (3) Evaluation error: The calculation results of the corrosion characteristic parameters of ribbed steel bars by traditional methods are often not accurate enough, and it is difficult to meet the high-precision evaluation requirements of the actual conditions of engineering structures. Therefore, it is of great significance to invent a technical method that can restore the uncorroded morphological contour of ribbed steel bars to solve the problems caused by their contour irregularity and data loss, which is of great significance to improve the accuracy of corrosion characteristic parameter calculation. Summary of the invention

[0004] In order to overcome one or more of the above-mentioned technical defects, the present invention provides a method for calculating the corrosion characteristic parameters of ribbed steel bars based on contour restoration, which realizes accurate calculation of the corrosion characteristic parameters by restoring the morphological contour of the ribbed steel bars before corrosion.

[0005] In order to solve the above problems, the present invention provides a method for calculating characteristic parameters of ribbed steel bar corrosion based on contour restoration, comprising the following steps:

[0006] S1, obtaining three-dimensional point cloud data of the surface contour of the corroded ribbed steel bar, and generating the corroded ribbed steel bar curved surface through coordinate transformation and binary interpolation;

[0007] S2. based on the time domain characteristics and frequency domain characteristics of the corroded ribbed steel bar surface, restore the original ribbed steel bar surface;

[0008] S3, comparing the corroded ribbed steel bar curved surface with the original ribbed steel bar curved surface, and calculating the corrosion characteristic parameters of the ribbed steel bar, wherein the corrosion characteristic parameters of the ribbed steel bar include the cross-sectional corrosion rate of the corroded ribbed steel bar η , Uneven corrosion coefficient ζ , Corrosion Depth δ and equivalent rust pit size.

[0009] Further, step S1 includes:

[0010] S11. Use the solid 3D reconstruction technology to collect the point cloud data of the surface morphology of the corroded ribbed steel bars. The point cloud data is in the form of 3D rectangular coordinates. (x, y, z) Represents that, where the plane of the three-dimensional rectangular coordinate system (y, z) Parallel to the cross section of the corroded ribbed steel bar; three-dimensional rectangular coordinate system x The axis coincides with the centerline of the corroded ribbed steel bar, 0< x<l , l is the length of the corroded ribbed steel bar;

[0011] S12, according to (1-1)-(1-2), the point cloud data is converted from three-dimensional rectangular coordinates (x, y, z) Convert to 3D polar coordinates (x, θ, r) :

[0012] (1-1)

[0013] (1-2)

[0014] in, r is the radial distance from each data point of the cross section of the corroded ribbed steel bar to the axis centerline, 0< r<d , d is the radial distance from the contour point of the corroded ribbed steel bar to the axis line. θ The plane of the line connecting the data points of the cross section of the corroded ribbed steel bar and the center of the cross section (y, z) Angle on, 0< θ < 2π ;

[0015] S13, the three-dimensional polar coordinate system (x, θ, r) The point cloud data below are respectively along z Axis direction at equal spacing Δx And along θ Axis direction at equal spacing Δθ Perform binary interpolation to construct the surface of corroded ribbed steel bars , the binary interpolation process is shown in (1-3):

[0016] (1-3)

[0017] in, i for x The interpolation point index in the axis direction, there are I discrete points; j for θ The interpolation point index in the axis direction, there are J discrete points; is the contour data point of the corroded ribbed steel bar ( , ), and They are x Axis and θ Interpolation function in the axis direction.

[0018] Further, step S2 includes:

[0019] S21, separating the corroded ribbed steel bar surface by frequency domain filtering technology The residual transverse rib signal in the image is used to obtain the corroded steel bar surface without transverse ribs. and residual transverse rib signal surface ;

[0020] S22, extracting the surface without transverse rib reinforcement The original longitudinal rib signal in the image is used to obtain the rib-free corroded steel bar surface. and the original longitudinal rib signal surface ;

[0021] S23, according to the residual transverse rib signal surface The periodic characteristics of the original transverse rib signal surface are restored ;

[0022] S24, constructing an original ribless steel bar curved surface according to the design size information of the corroded ribbed steel bar , the original unribbed steel surface , the original transverse rib signal surface and the original longitudinal rib signal surface , calculated according to (1-4), the original ribbed steel bar surface is obtained :

[0023] (1-4).

[0024] Further, step S21 includes:

[0025] S211, extracting the corroded ribbed steel bar surface All local minimum points of , and interpolate to form the minimum envelope surface through the binary interpolation algorithm ;

[0026] S212, the corroded ribbed steel bar curved surface and the minimum envelope surface Subtract according to (1-5) to obtain the minimum envelope surface :

[0027] (1-5);

[0028] S213, removing the minimum envelope surface Welch power spectrum estimation is performed to obtain the power spectrum density diagram of the residual cross-rib signal, and the main frequencies of the residual cross-rib signal are extracted respectively. Its bandwidth , second harmonic frequency Its bandwidth ; The de-minimization envelope surface The power spectral density Calculate according to (1-6)-(1-7):

[0029] (1-6)

[0030] (1-7)

[0031] in, is the de-minimization envelope surface At different angles The segmented signal The power spectral density of M For the segment signal The number of intervals divided into subintervals, m is the subinterval index, It means to perform Fourier transform on the time domain signal in brackets;

[0032] S214, through (1-8), the de-minimization envelope surface Perform frequency domain filtering to obtain the filtered envelope surface without transverse ribs and de-minimization ; No cross ribs corroded steel bar surface and residual transverse rib signal surface Using (1-9)-(1-10) to calculate:

[0033] (1-8)

[0034] (1-9)

[0035] (1-10)

[0036] in, Indicates the inverse Fourier transform of the frequency domain signal in the brackets. H b1 (ω) and H b2 (ω) The main frequencies are ω 1 and the second harmonic frequency ω 2 frequency domain transfer function of the band-stop filter.

[0037] Furthermore, step S22 specifically includes:

[0038] S221. Use the existing extreme value detection method to extract the main peak line of each longitudinal rib signal And the corresponding longitudinal rib width , and the signal area of ​​each longitudinal rib is

[0039] ,

[0040] Then the residual longitudinal rib contour curve corresponding to each longitudinal rib signal area is ; The main peak line of the longitudinal rib signal Satisfy the requirements of (1-11)-(1-12):

[0041] (1-11)

[0042] (1-12)

[0043] in, k is the index of the longitudinal rib signal of the ribbed steel bar, k =1,2… K , K is the total number of longitudinal ribs with equal spacing between ribbed steel bars, Δθ min =2π / K Arrange the spacing of the longitudinal ribs in the angular direction for the ribbed steel bars;

[0044] S222, all the scattered point data of the residual longitudinal rib profile curve are transformed by coordinate translation according to (1-13)-(1-14), and a plane coordinate system is drawn. (R, Θ) In , a scattered data set of the residual longitudinal rib profile is formed:

[0045] (1-13)

[0046] (1-14);

[0047] S223, using the existing scattered point outer contour extraction method, in the plane coordinate system (R L , Θ L ) The outer contour of the scattered data of the residual longitudinal rib profile is extracted, and the original longitudinal rib profile function is obtained by fitting with a one-dimensional Gaussian function ;

[0048] S224, the longitudinal rib original profile function along x Constant extension in the axial direction to form the original single longitudinal rib contour surface , and according to the main peak line of each longitudinal rib signal Position, through coordinate translation transformation, the original longitudinal rib signal surface is constructed , to obtain the rib-free corroded steel bar surface :

[0049] (1-15).

[0050] Further, step S23 includes:

[0051] S231, in the non-longitudinal rib signal area In the figure, the signal area of ​​each row of residual transverse ribs is , the residual transverse rib signal surface corresponding to each row of transverse rib signal areas According to (1-16), the signal surface of the residual cross rib perpendicular to the axis is obtained by rotating and performing bilinear interpolation. :

[0052] (1-16)

[0053] in, is the angle between the transverse rib and the steel bar axis;

[0054] S232, the residual transverse rib signal surface perpendicular to the axis According to (1-17)-(1-19), vertical flip, horizontal flip, and 180° rotation are performed respectively, and the maximum value is taken according to (20) to obtain the sub-transverse rib signal surface perpendicular to the axis. :

[0055] (1-17)

[0056] (1-18)

[0057] (1-19)

[0058] (1-20)

[0059] in, , and are the results of vertical flipping, horizontal flipping and 180° rotation of the residual transverse rib signal surface perpendicular to the axis;

[0060] S233, using an extreme value detection method to extract the secondary transverse rib signal surface perpendicular to the axis The main peak point of each transverse rib signal , the signal area of ​​a single vertical transverse rib is obtained as:

[0061] ,

[0062] in, is the index of the transverse rib signal of the ribbed steel bar, =1,2… H × K , H is the total number of ribbed steel bars arranged at equal intervals in each row of transverse rib signal areas, and the corresponding single vertical secondary transverse rib signal surface is ; The main peak point of the transverse rib signal Satisfies (1-21) - (1-24):

[0063] (1-21)

[0064] (1-22)

[0065] (1-23)

[0066] (1-24)

[0067] in, is the distance between each transverse rib of the ribbed steel bar;

[0068] S234, performing coordinate translation transformation on all the scattered point data of the single vertical sub-transverse rib signal surfaces according to (1-25)-(1-26) to generate a scattered point data set of the vertical sub-transverse rib signal surface, and extracting the outer contour of the scattered point in the coordinate system through the existing scattered point outer contour extraction method. The outer contour of the scattered data of the vertical secondary transverse rib signal surface is extracted, and a single vertical original transverse rib contour surface is obtained by fitting with a two-dimensional Gaussian function. ,

[0069] (1-25)

[0070] (1-26);

[0071] S235, converting the single vertical original transverse rib profile function According to (1-27), the original transverse rib profile surface is obtained by rotating it and using the existing method for bilinear interpolation. :

[0072] (1-27)

[0073] And according to the main peak point of each row of transverse rib signals Position, the original transverse rib signal surface is constructed by coordinate translation transformation .

[0074] Further, step S3 includes:

[0075] S31, the cross-sectional corrosion rate of the corroded ribbed steel bar η Including cross-sectional corrosion rate distribution η i , Maximum cross-section corrosion rate η max and average cross-sectional corrosion rate η ave ,

[0076] Calculate the cross-section corrosion rate distribution η i : (1-28)

[0077] Calculate the maximum cross-sectional corrosion rate η max : (1-29)

[0078] Calculate the average cross-section corrosion rate η ave : (1-30);

[0079] S32, the corrosion unevenness coefficient of the corroded ribbed steel bar ζ Including the uneven coefficient of overall corrosion of steel bars ζ all and the uneven coefficient of local corrosion of steel bars ζ sec,w , based on the maximum cross-sectional corrosion rate η max and average cross-sectional corrosion rate η ave ,

[0080] Calculation of the uneven coefficient of overall corrosion of steel bars ζ all :

[0081] (1-31)

[0082] Calculation of the uneven coefficient of local corrosion of steel bars ζ sec,w : , (1-32)

[0083] in, s is the length of the unit locally intercepted on the steel bar, and there is a weak correlation between the units. w =1, 2, ..., W, W is the length of the steel bar s The total number of intercept units;

[0084] S33, the corrosion depth of the corroded ribbed steel bar δ Including corrosion depth distribution function δ i,j , Maximum corrosion depth δ max and average corrosion depth δ ave ,

[0085] Calculate the corrosion depth distribution function δ i,j : (1-33)

[0086] Calculation of maximum corrosion depth δ max : (1-34)

[0087] Calculation of average corrosion depth δ ave : (1-35).

[0088] The present invention also provides a ribbed steel bar corrosion characteristic parameter calculation system based on contour restoration, which is used to implement the above method, including:

[0089] A data processing module is used to obtain three-dimensional point cloud data of the surface contour of the corroded ribbed steel bar, perform coordinate transformation and binary interpolation processing on the three-dimensional point cloud data, and generate a corroded ribbed steel bar curved surface;

[0090] The steel bar surface restoration module is used to restore the original ribbed steel bar surface based on the time domain characteristics and frequency domain characteristics of the corroded ribbed steel bar surface;

[0091] The steel bar corrosion characteristic parameter calculation module is used to compare the corroded ribbed steel bar surface with the original ribbed steel bar surface and calculate the ribbed steel bar corrosion characteristic parameters, where the ribbed steel bar corrosion characteristic parameters include the cross-sectional corrosion rate of the corroded ribbed steel bar. η , Uneven corrosion coefficient ζ, Corrosion Depth δ and equivalent rust pit size.

[0092] The present invention also provides a computer device, comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the above method when executing the computer program.

[0093] The present invention also provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the above method are implemented.

[0094] Compared with the prior art, the present invention has the following advantages and effects:

[0095] (1) The present invention transforms the point cloud data of the corroded ribbed steel bar contour into a three-dimensional polar coordinate system, and uses the changes in radial distance and azimuth angle to clearly represent the rib shape characteristics and corrosion distribution of the corroded ribbed steel bar, so as to facilitate the subsequent more efficient separation of the corroded steel bar transverse ribs, longitudinal ribs and inner diameter surface.

[0096] (2) The present invention uses power spectrum estimation method and frequency domain filtering technology to effectively identify the main frequency, bandwidth and other information of the residual transverse rib signal of the corroded ribbed steel bar, accurately extract the residual transverse rib signal, and then combine the scattered point boundary line extraction technology to accurately separate the longitudinal rib signal and the ribless corroded steel bar signal, significantly reducing the influence of rib shape characteristics on the calculation of ribbed steel bar corrosion characteristic parameters, and providing an effective data basis for the subsequent calculation of equivalent corrosion pit size information.

[0097] (3) The present invention accurately locates the main peak position of the transverse rib and longitudinal rib signals through the extreme value detection algorithm, and accurately reconstructs the surface morphology of the original transverse rib and longitudinal rib. At the same time, combined with the ribless steel bar surface based on the designed inner diameter of the steel bar, the original contour surface of the ribbed steel bar before corrosion is successfully restored under the condition of maintaining the original rib shape characteristics, providing an accurate restoration method from the actual corrosion state to the original state, reducing the calculation deviation of the corrosion characteristics caused by missing or over-simplified measurement data.

[0098] (4) The present invention restores the original surface profile of the ribbed steel bars before corrosion by integrating the time domain and frequency domain characteristics of the corroded ribbed steel bars, thereby avoiding the error of simplifying the ribbed steel bars into round steel bars in the traditional technology, effectively solving the measurement problem of the ribbed steel bars caused by the irregularity of the rib shape, ensuring the comprehensiveness and accuracy of the corrosion characteristic parameters, and providing a reliable basis for the subsequent prediction of structural rust expansion cracking and performance evaluation. BRIEF DESCRIPTION OF THE DRAWINGS

[0099] The specific embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings, wherein:

[0100] Figure 1This is a schematic flow chart of the method for calculating characteristic parameters of ribbed steel bar corrosion based on contour restoration described in Example 1;

[0101] Figure 2 A three-dimensional scanning model diagram of a corroded ribbed steel bar according to the method for calculating characteristic parameters of ribbed steel bar corrosion based on contour restoration described in Example 1;

[0102] 3 (a) and (b) are respectively the surface contour curved surface of the corroded ribbed steel bar and its top view of the method for calculating characteristic parameters of ribbed steel bar corrosion based on contour restoration described in Example 1;

[0103] 4 (a) and (b) are respectively a two-dimensional power spectrum density diagram of the residual transverse rib signal and a top view thereof of the method for calculating characteristic parameters of ribbed steel bar corrosion based on contour restoration described in Example 1;

[0104] 5 (a) and (b) are respectively the original longitudinal rib surface contour surface of the corroded ribbed steel bar and its top view according to the method for calculating the characteristic parameters of ribbed steel bar corrosion based on contour restoration described in Example 1;

[0105] 6 (a) and (b) are respectively the surface contour curved surface of the non-ribbed corroded ribbed steel bar and its top view according to the method for calculating the characteristic parameters of ribbed steel bar corrosion based on contour restoration described in Example 1;

[0106] Figure 7 A three-dimensional model diagram of a rib-free corroded ribbed steel bar according to the method for calculating characteristic parameters of ribbed steel bar corrosion based on contour restoration described in Example 1;

[0107] 8 (a) and (b) are respectively a surface contour curve of a single original transverse rib of a corroded steel bar and its top view according to the method for calculating characteristic parameters of ribbed steel bar corrosion based on contour restoration described in Example 1;

[0108] 9 (a) and (b) are respectively the original steel bar surface contour surface of the corroded steel bar and its top view according to the method for calculating characteristic parameters of ribbed steel bar corrosion based on contour restoration described in Example 1;

[0109] Figure 10 A three-dimensional model diagram of an uncorroded ribbed steel bar according to the method for calculating characteristic parameters of ribbed steel bar corrosion based on contour restoration described in Example 1;

[0110] 11 (a) and (b) are respectively a cross-sectional corrosion rate distribution curve and a histogram of the corroded ribbed steel bar according to the method for calculating characteristic parameters of ribbed steel bar corrosion based on contour restoration described in Example 1;

[0111] 12 (a) and (b) are respectively a corrosion depth distribution curve surface of the corroded steel bar and a top view thereof according to the method for calculating characteristic parameters of corrosion of ribbed steel bars based on contour restoration described in Example 1;

[0112] Figure 13 This is a schematic diagram of the structure of the device described in Example 3. DETAILED DESCRIPTION

[0113] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0114] Example 1

[0115] This embodiment provides a method for calculating characteristic parameters of ribbed steel bar corrosion based on contour restoration. Figure 1 ,include:

[0116] S11. Remove a length of l =450mm, quality corrosion rate is η s =11.14%, the maximum cross-section corrosion rate η s,max =37.70% of the corroded ribbed steel bar Rebar, the point cloud data of the surface morphology of the corroded ribbed steel bar was collected using the solid 3D reconstruction technology. The point cloud data was in the 3D rectangular coordinate system. (x, y, z) Indicates that, the plane (y, z) Parallel to the cross section of the corroded ribbed steel bars; x The axis coincides with the axis centerline of the corroded ribbed steel bar, 0< x<l . Use 3D modeling software to build a 3D solid model such as Figure 2 shown.

[0117] S12. According to (2-1)-(2-2), Rebar’s point cloud data is transformed from a three-dimensional rectangular coordinate system (x, y, z) Transform to obtain a three-dimensional polar coordinate system (x, θ, r) :

[0118] (2-1)

[0119] (2-2)

[0120] in, r is the radial distance from each data point of the cross section of the corroded ribbed steel bar to the axis centerline, 0< r<d , d is the radial distance from the contour point of the corroded ribbed steel bar to the axis line. θ The plane of the line connecting the data points of the cross section of the corroded ribbed steel bar and the center of the cross section (y, z) Angle on, 0< θ < 2π .

[0121] S13. Three-dimensional polar coordinate system(x, θ, r) Download Rebar's point cloud data, respectively along z Axis direction at equal spacing Δx =450 / 512mm and along θ Axis direction at equal spacing Δθ =2π / 512 for binary interpolation, and the surface contour of the corroded ribbed steel bar of Rebar is constructed , as shown in Figure 3 (a) and (b), are the surface contour curve of the corroded ribbed steel bar and its top view; the binary interpolation processing is shown in (2-3):

[0122] (2-3)

[0123] in, i for x The interpolation point index in the axis direction, there are I =512 discrete points; j for θ The interpolation point index in the axis direction, there are J =512 discrete points, total number of surface points I × J =262144; is the rebar profile data point of the corroded ribbed Rebar ( , ), and They are x Axis and θ Interpolation function in the axis direction.

[0124] S211, Extract the surface contour of the corroded ribbed steel bar of Rebar All local minimum points of , and interpolate to form the minimum envelope surface of Rebar through the binary interpolation algorithm ;

[0125] S212, the surface contour of the corroded ribbed steel bar of Rebar and minimum envelope surface Subtract according to (2-4) to obtain the Rebar de-minimization envelope surface :

[0126] (2-4)

[0127] S213, Rebar's de-minimization envelope surface Welch power spectrum estimation is performed to obtain the two-dimensional power spectrum density diagram of the residual cross-rib signal of Rebar, as shown in Figure 4 (a) and (b); and the main frequencies of the residual cross-rib signal of Rebar are extracted respectively. =0.14 and its bandwidth Δ =0.06, second harmonic frequency =0.27 and its bandwidth Δ = 0.06. Rebar's de-minimization envelope surface The power spectral density Calculate according to (2-5)-(2-6):

[0128] (2-5)

[0129] (2-6)

[0130] in, is the Rebar's deminimization envelope surface At different angles The segmented signal The power spectral density of M Rebar segment signal The number of intervals divided into subintervals, m is the subinterval index, Indicates Fourier transform of the time domain signal in brackets.

[0131] S214, through (2-7), the minimum envelope surface of Rebar Perform frequency domain filtering to obtain the filtered envelope surface without transverse ribs and de-minimization ; Rebar's corroded steel bar surface without transverse ribs and residual transverse rib signal surface Use (2-8)-(2-9) to calculate respectively:

[0132] (2-7)

[0133] (2-8)

[0134] (2-9)

[0135] in, Indicates the inverse Fourier transform of the frequency domain signal in the brackets. H b1 (ω) and H b2 (ω) They are the main frequencies of Rebar ω 1st and 2nd harmonic frequencies ω 2 frequency domain transfer function of the band-stop filter.

[0136] S221, extract the main peak line of each longitudinal rib signal of Rebar through the extreme value detection method And the corresponding longitudinal rib width , and the signal area of ​​each longitudinal rib is

[0137]

[0138] Then the residual longitudinal rib contour curve corresponding to each longitudinal rib signal area of ​​Rebar is The main peak line of the Rebar longitudinal rib signal Satisfies (2-10)-(2-11):

[0139] (2-10)

[0140] (2-11)

[0141] In the formula, k is the index of the longitudinal rib signal of the ribbed steel bar, k =1,2… K , K =2 is the total number of longitudinal ribs of Rebar ribbed steel bars arranged at equal intervals, Δ θ min =π is the spacing of the longitudinal ribs of the ribbed steel bars in the angular direction.

[0142] S222. Perform coordinate translation transformation on all scattered point data of the Rebar residual longitudinal rib profile curve according to (2-12)-(2-13), and draw the plane coordinate system (R, Θ) In the above figure, a scattered data set of the residual longitudinal rib profile is formed.

[0143] (2-12)

[0144] (2-13)

[0145] S223, through the scattered point outer contour extraction method, in the two-dimensional polar coordinate system (R L , Θ L ) The outer contour of the scattered data of the Rebar residual longitudinal rib contour is extracted, and the original contour function of the longitudinal rib is obtained by fitting with a Gaussian function: .

[0146] S224, the original contour function of the longitudinal rib of Rebar along x The axis direction is constantly extended to form a three-dimensional polar coordinate system ( x, R L , Θ L ) Original single longitudinal rib contour surface: , and according to the main peak line of each longitudinal rib signal Position, through coordinate translation transformation, the original longitudinal rib signal surface is constructed , as shown in Figure 5 (a) and (b), the original longitudinal rib surface contour surface of the corroded ribbed steel bar and its top view; the surface of the non-ribbed corroded steel bar According to (2-14), we can get:

[0147] (2-14).

[0148] As shown in Figure 6 (a) and (b), the surface contour curve of the un-ribbed corroded ribbed steel bar and its top view; Figure 7 , which is a three-dimensional model diagram of corroded ribbed steel bars without ribs. It can be seen that the transverse ribs and longitudinal ribs on the surface of the corroded ribbed steel bars have obviously disappeared.

[0149] S231, in the non-longitudinal rib signal area In the Rebar, the signal area of ​​each row of residual transverse ribs is , the residual transverse rib signal surface corresponding to each row of transverse rib signal area of ​​Rebar According to (2-15), the Rebar residual cross-rib signal surface perpendicular to the axis is obtained by rotating and performing bilinear interpolation. :

[0150] (2-15)

[0151] in, =3.4 rad is the angle between the transverse rib and the axis of the reinforcement.

[0152] S232, the Rebar residual cross rib signal surface perpendicular to the axis According to (2-16)-(2-18), vertical flip, horizontal flip, and 180° rotation are performed respectively, and according to (2-19), the maximum value among the original data, the data after vertical flip, the data after horizontal flip, and the data after 180° rotation is taken to obtain the sub-transverse rib signal surface perpendicular to the axis. :

[0153] (2-16)

[0154] (2-17)

[0155] (2-18)

[0156] (2-19)

[0157] in, , and These are the results of vertical flipping, horizontal flipping and 180° rotation of the Rebar residual transverse rib signal surface perpendicular to the axis.

[0158] S233, using the extreme value detection method to extract the Rebar secondary transverse rib signal surface perpendicular to the axis The main peak point of each transverse rib signal , the signal area of ​​a single vertical cross rib of Rebar is

[0159] ,

[0160] in, is the index of the transverse rib signal of the ribbed steel bar, =1,2… H × K , H =2 is the total number of transverse ribs of the ribbed steel bar Rebar arranged at equal intervals in the signal area of ​​each row of transverse ribs of Rebar; is the coordinate value of the main peak line of the longitudinal rib signal After the coordinate transformation (2-15), the corresponding single vertical sub-transverse rib signal surface is Rebar the main peak point of each transverse rib signal Satisfies (2-20)-(2-23):

[0161] (2-20)

[0162] (2-21)

[0163] (2-22)

[0164] (2-23)

[0165] in, =7.1429mm is the distance between each transverse rib of the ribbed steel bar.

[0166] S234, coordinate translation transformation is performed on the scattered point data of all single vertical sub-transverse rib signal surfaces of Rebar according to (2-24) and (2-25) to form a scattered point data set of the vertical Rebar sub-transverse rib signal surface, and the scattered point outer contour extraction method is used to extract the scattered point data set in the coordinate system. The outer contour of the scattered data of the vertical Rebar secondary transverse rib signal surface is extracted, and a single vertical Rebar original transverse rib contour surface is obtained by fitting with a two-dimensional Gaussian function:

[0167] .

[0168] (2-24)

[0169] (2-25)

[0170] S235, the original transverse rib profile function of a single vertical Rebar According to (2-26), the surface contour of the single original transverse rib of Rebar is obtained by rotating and performing bilinear interpolation. , as shown in Figure 8 (a) and (b), the surface contour curve of a single original transverse rib of the corroded ribbed steel bar and its top view respectively:

[0171] (2-26)

[0172] According to the main peak point of each row of transverse rib signals of Rebar Position, through coordinate translation transformation, the Rebar original cross rib signal surface contour surface is constructed .

[0173] S24. According to the design dimension information of the corroded ribbed steel bar Rebar, the inner diameter of Rebar is 12.1 mm. The original ribless steel bar surface of Rebar is constructed. , the original unribbed steel surface of Rebar , Original longitudinal rib signal surface and the original longitudinal rib signal surface According to (27), we add the original steel bar surface contour surface of Rebar :

[0174] (2-27)

[0175] As shown in Figure 9 (a) and (b), the original steel bar surface contour surface and its top view are shown respectively; Figure 10 According to the original steel bar surface contour surface The obtained three-dimensional model of the uncorroded ribbed steel bar.

[0176] S31, Corrosion rate of the cross section of the corroded ribbed steel bar Rebar η Including cross-sectional corrosion rate distribution η i , Maximum cross-section corrosion rate η max and average cross-sectional corrosion rate η ave ,

[0177] Calculate the cross-section corrosion rate distribution η i : (2-28)

[0178] Calculate the maximum cross-sectional corrosion rate η max : (2-29)

[0179] Calculate the average cross-section corrosion rate η ave : (2-30).

[0180] In this embodiment, the cross-sectional corrosion rate distribution curve and histogram of the corroded ribbed steel bar Rebar are shown in (a) and (b) of FIG11 , and the average cross-sectional corrosion rate calculated is η ave and maximum cross-sectional corrosion rate η max They are 11.08% and 37.30% respectively, which is consistent with the actual measured quality corrosion rate. η s =11.14%, maximum cross-section corrosion rate η s,max =37.70%, and the error is within 1%.

[0181] S32, Corrosion Unevenness Coefficient of Corroded Ribbed Steel Bar Rebar ζ Including the uneven coefficient of overall corrosion of steel bars ζ all and the uneven coefficient of local corrosion of steel bars ζ sec,w , based on the maximum cross-sectional corrosion rate η max and average cross-sectional corrosion rate η ave ,

[0182] Calculation of the uneven coefficient of overall corrosion of steel bars ζ all :

[0183] (2-31)

[0184] Calculation of the uneven coefficient of local corrosion of steel bars ζ sec,w : , (2-32)

[0185] in, s is the length of the unit locally intercepted on the steel bar. These units show a weak correlation. w =1, 2, …, W , W =9 is the total number of steel bar units cut with a length of s=50mm.

[0186] In this embodiment, the overall corrosion unevenness coefficient of the steel bar Rebar calculated is ζ all is 3.3653, and the distribution of uneven coefficient of local corrosion of steel bars ζ sec,w As shown in Table 1.

[0187] Table 1 Distribution of the uneven coefficient of local corrosion of the corroded ribbed steel bar Rebar

[0188]

[0189] S33, Corrosion depth of rusted ribbed steel bars Rebar δ Including corrosion depth distribution function δ i,j , Maximum corrosion depth δ max and average corrosion depth δ ave ,

[0190] Calculate the corrosion depth distribution function δ i,j : (2-33)

[0191] Calculation of maximum corrosion depth δ max : (2-34)

[0192] Calculation of average corrosion depth δ ave : (2-35).

[0193] In this embodiment, the corrosion depth distribution curve of the corroded ribbed steel bar Rebar δ i,j As shown in (a) and (b) of Figure 12, the maximum corrosion depth δ max =5.8956mm, average corrosion depth δ ave =0.8326mm, while the maximum corrosion depth and average corrosion depth calculated by the traditional method are 5.5965mm and 0.7452mm respectively. The corrosion depth parameter calculated by the method provided by the present invention can be used to calculate the rust expansion stress of ribbed steel bars in concrete, providing data support for the refined prediction of cracking of concrete cover.

[0194] Example 2

[0195] This embodiment provides a ribbed steel bar corrosion characteristic parameter calculation system based on contour restoration, which is used to implement the above method, including a data processing module, a steel bar surface restoration module and a steel bar corrosion characteristic parameter calculation module. The data processing module is used to obtain the three-dimensional point cloud data of the surface contour of the corroded ribbed steel bar, perform coordinate transformation and binary interpolation processing on the three-dimensional point cloud data, and generate the corroded ribbed steel bar surface; the steel bar surface restoration module is used to restore the original ribbed steel bar surface based on the time domain characteristics and frequency domain characteristics of the corroded ribbed steel bar surface; the steel bar corrosion characteristic parameter calculation module is used to compare the corroded ribbed steel bar surface with the original ribbed steel bar surface, and calculate the ribbed steel bar corrosion characteristic parameters, wherein the ribbed steel bar corrosion characteristic parameters include the cross-sectional corrosion rate of the corroded ribbed steel bar η , Uneven corrosion coefficient ζ , Corrosion Depth δ and equivalent rust pit size.

[0196] For other specific implementation details, please refer to Example 1, which will not be repeated here.

[0197] Example 3

[0198] This embodiment provides an electronic device, including a memory and a processor, wherein the memory stores a computer program, and the processor implements the method described in Embodiment 1 when executing the program.

[0199] Figure 13 An example of a physical structure diagram of an electronic device is shown in FIG. Figure 13 As shown, the electronic device may include: a processor 210, a communication interface 220, a memory 230 and a communication bus 240, wherein the processor 210, the communication interface 220 and the memory 230 communicate with each other through the communication bus 240. The processor 210 may call the logic instructions in the memory 230 to execute the following method: obtaining the three-dimensional point cloud data of the surface contour of the corroded ribbed steel bar, performing coordinate transformation and binary interpolation processing on the three-dimensional point cloud data, and generating the corroded ribbed steel bar surface; based on the time domain characteristics and frequency domain characteristics of the corroded ribbed steel bar surface, restoring the original ribbed steel bar surface; comparing the corroded ribbed steel bar surface with the original ribbed steel bar surface, and calculating the ribbed steel bar corrosion characteristic parameters.

[0200] In addition, the logic instructions in the above-mentioned memory 230 can be implemented in the form of software functional units and can be stored in a computer-readable storage medium when sold or used as an independent product. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0201] Example 4

[0202] The present embodiment provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the method provided in Embodiment 1 is implemented, for example, including: obtaining three-dimensional point cloud data of the surface contour of the corroded ribbed steel bar, performing coordinate transformation and binary interpolation processing on the three-dimensional point cloud data, and generating a corroded ribbed steel bar surface; restoring the original ribbed steel bar surface based on the time domain characteristics and frequency domain characteristics of the corroded ribbed steel bar surface; comparing the corroded ribbed steel bar surface with the original ribbed steel bar surface, and calculating the ribbed steel bar corrosion characteristic parameters.

[0203] A person of ordinary skill in the art can understand that all or part of the steps of implementing the above method embodiment can be completed by hardware related to program instructions, and the aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps of the above method embodiment; and the aforementioned storage medium includes: ROM, RAM, magnetic disk or optical disk, etc., various media that can store program codes.

[0204] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0205] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0206] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

[0207] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Therefore, any modification, equivalent change and modification made to the above embodiment based on the technical essence of the present invention without departing from the technical solution of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A method for calculating characteristic parameters of ribbed steel bar corrosion based on contour restoration, characterized in that: The steps include: Obtain the three-dimensional point cloud data of the surface contour of the corroded ribbed steel bar, perform coordinate transformation and binary interpolation processing on the three-dimensional point cloud data, and generate the corroded ribbed steel bar curved surface; Based on the time domain characteristics and frequency domain characteristics of the corroded ribbed steel bar surface, the original ribbed steel bar surface is restored, including the following steps: Corroded ribbed steel bar surface Perform frequency domain filtering to separate the residual transverse rib signal and obtain the surface of the steel bar without transverse rib corrosion. and residual transverse rib signal surface ; Extract the surface of corroded steel bars without transverse ribs The original longitudinal rib signal in the image is used to obtain the rib-free corroded steel bar surface. and the original longitudinal rib signal surface ; Based on residual transverse rib signal surface The periodic characteristics of the original transverse rib signal surface are restored ; Construct the original unribbed steel bar surface based on the design size information of the corroded ribbed steel bar , the original unribbed steel surface , original transverse rib signal surface , Original longitudinal rib signal surface Add together to get the original ribbed steel bar surface ; The corroded ribbed steel bar surface is compared with the original ribbed steel bar surface to calculate the ribbed steel bar corrosion characteristic parameters, where the ribbed steel bar corrosion characteristic parameters include the cross-sectional corrosion rate of the corroded ribbed steel bar η , Uneven corrosion coefficient ζ , Corrosion Depth δ and equivalent rust pit size, including the following steps: Cross-sectional corrosion rate of corroded ribbed steel bars η Including cross-sectional corrosion rate distribution η i , Maximum cross-section corrosion rate η max and average cross-sectional corrosion rate η ave , calculate the cross-section corrosion rate distribution η i : Calculate the maximum cross-sectional corrosion rate η max : Calculate the average cross-section corrosion rate η ave : Corrosion non-uniformity coefficient of corroded ribbed steel bars ζ Including the uneven coefficient of overall corrosion of steel bars ζ all and the uneven coefficient of local corrosion of steel bars ζ sec,w , based on the maximum cross-sectional corrosion rate η max and average cross-sectional corrosion rate η ave , calculate the uneven coefficient of overall steel corrosion ζ all : Calculation of the uneven coefficient of local corrosion of steel bars ζ sec,w : in, s is the length of the unit locally intercepted on the steel bar, and there is a weak correlation between the units. w =1, 2, ..., W, W is the length of the steel bar s The total number of intercept units; Corrosion depth of corroded ribbed steel bars δ Including corrosion depth distribution function δ i,j , Maximum corrosion depth δ max and average corrosion depth δ ave , calculate the corrosion depth distribution function δ i,j : Calculation of maximum corrosion depth δ max : Calculation of average corrosion depth δ ave : .

2. The method for calculating characteristic parameters of ribbed steel bar corrosion according to claim 1, characterized in that: The step of obtaining three-dimensional point cloud data of the surface contour of the corroded ribbed steel bar, performing coordinate transformation and binary interpolation processing on the three-dimensional point cloud data, and generating a surface of the corroded ribbed steel bar includes the following steps: Collect point cloud data of the surface morphology of corroded ribbed steel bars. The point cloud data is in three-dimensional rectangular coordinates. (x,y,z) Represents that, where the plane of the three-dimensional rectangular coordinate system (y,z) Parallel to the cross section of the corroded ribbed steel bar, the three-dimensional rectangular coordinate system x The axis coincides with the centerline of the corroded ribbed steel bar, 0< x< l , l is the length of the corroded ribbed steel bar; Convert point cloud data from 3D rectangular coordinates (x,y,z) Convert to 3D polar coordinates (x,θ,r) : The point cloud data in three-dimensional polar coordinates are respectively z Axis direction at equal spacing And along Direction by equal spacing Perform binary interpolation to construct the surface of corroded ribbed steel bars .

3. The method for calculating characteristic parameters of ribbed steel bar corrosion according to claim 1, characterized in that: Steps for corroded ribbed steel bar surface Perform frequency domain filtering to separate the residual transverse rib signal and obtain the surface of the steel bar without transverse rib corrosion. and residual transverse rib signal surface The steps include: Extracting the surface of corroded ribbed steel bars All local minimum points of , and perform binary interpolation on all local minimum points to form the minimum envelope surface ; The corroded ribbed steel bar surface and minimum envelope surface Subtract to obtain the minimum envelope surface ; De-minimizing envelope surface Welch power spectrum estimation is performed to obtain the power density diagram of the residual cross-rib signal, and the main frequencies of the residual cross-rib signal are extracted respectively. Its bandwidth , second harmonic frequency Its bandwidth ; De-minimizing envelope surface Perform frequency domain filtering to obtain the filtered envelope surface without transverse ribs and de-minimization ; De-minimize the envelope surface without transverse ribs and minimum envelope surface Add them together to get the surface of the steel bar without corroded cross ribs ; The rusted ribbed steel bar surface Corroded steel bar surface with no cross ribs Subtract to obtain the residual transverse rib signal surface .

4. The method for calculating characteristic parameters of ribbed steel bar corrosion according to claim 1, characterized in that: Step 1 Extract the surface of corroded steel bars without cross ribs The original longitudinal rib signal in the image is used to obtain the rib-free corroded steel bar surface. and the original longitudinal rib signal surface The steps include: Extract the main peak line of each longitudinal rib signal And the corresponding longitudinal rib width , get the signal area of ​​each longitudinal rib And the residual longitudinal rib profile curve corresponding to each longitudinal rib signal area ; Perform coordinate translation transformation on the scattered point data of all residual longitudinal rib profile curves and draw them into the plane coordinate system (R,Θ) In , a scattered data set of residual longitudinal rib profiles is generated; In the plane coordinate system (R L ,Θ L ) The outer contour of the scattered data of the residual longitudinal rib profile is extracted, and the original longitudinal rib profile function is obtained by fitting with a one-dimensional Gaussian function. ; The original contour function of the longitudinal rib along x Constant extension in the axial direction to form the original single longitudinal rib contour surface , and according to the main peak line of each longitudinal rib signal Position, through coordinate translation transformation, construct the original longitudinal rib signal surface , to obtain the rib-free corroded steel bar surface .

5. The method for calculating characteristic parameters of ribbed steel bar corrosion according to claim 1, characterized in that: Step Based on the residual cross rib signal surface The periodic characteristics of the original transverse rib signal surface are restored , including the following steps: In the non-longitudinal rib signal area In the figure, the signal area of ​​each row of residual transverse ribs is , the residual transverse rib signal surface corresponding to each row of transverse rib signal area Perform rotation and bilinear interpolation to obtain the residual cross-rib signal surface perpendicular to the axis ; The residual transverse rib signal surface perpendicular to the axis Perform vertical flip, horizontal flip and 180° rotation, take the maximum value of the flipped data, and obtain the sub-transverse rib signal surface perpendicular to the axis ; Extract the signal surface of the secondary transverse rib perpendicular to the axis The main peak point of each transverse rib signal , get the single vertical cross rib signal area ,in, is the index of the transverse rib signal of the ribbed steel bar, =1,2…H×K, H is the total number of ribbed steel bars arranged at equal intervals in each row of transverse rib signal area, then the corresponding single vertical secondary transverse rib signal surface is ; The scattered point data of all single vertical sub-transverse rib signal surfaces are transformed by coordinate translation to generate a scattered point data set of the vertical sub-transverse rib signal surface and The outer contour of the vertical secondary transverse rib signal surface is extracted from the scattered data, and a single vertical original transverse rib contour surface is obtained by fitting the two-dimensional Gaussian function. ; The original transverse rib profile function of a single vertical Perform rotation and bilinear interpolation to obtain a single original transverse rib profile surface , and according to the main peak position of each row of transverse rib signals , the original transverse rib signal surface is constructed by coordinate translation transformation .

6. A ribbed steel bar corrosion characteristic parameter calculation system based on contour restoration, used to implement the ribbed steel bar corrosion characteristic parameter calculation method according to any one of claims 1 to 5, characterized in that: include: A data processing module is used to obtain three-dimensional point cloud data of the surface contour of the corroded ribbed steel bar, perform coordinate transformation and binary interpolation processing on the three-dimensional point cloud data, and generate a corroded ribbed steel bar curved surface; The steel bar surface restoration module is used to restore the original ribbed steel bar surface based on the time domain characteristics and frequency domain characteristics of the corroded ribbed steel bar surface; The steel bar corrosion characteristic parameter calculation module is used to compare the corroded ribbed steel bar surface with the original ribbed steel bar surface and calculate the ribbed steel bar corrosion characteristic parameters, where the ribbed steel bar corrosion characteristic parameters include the cross-sectional corrosion rate of the corroded ribbed steel bar. η , Uneven corrosion coefficient ζ , Corrosion Depth δ and equivalent rust pit size.

7. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 5 are implemented.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 5 are implemented.

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