In-situ nondestructive testing device and method for corroded steel structure

Abstract

The application discloses a kind of rusted steel structure in situ nondestructive testing device and method, device includes multiple fixed bands and multiple sensing bands, enclosed in the outer side of the steel structure to be measured, for the frame structure consistent with the shape of the steel structure to be measured;The outer side of fixed band is used to connect the climbing car group, the inner side is used to connect sensing band;Climbing car group can drive entire nondestructive testing device to climb or descend along the surface of the steel structure to be measured;Acquisition equipment, collect and pre-process the data of sensing band.The rusted steel structure in situ nondestructive testing device of the application is bent by fixed band, adjusts the corner connection fixed device to adapt to different sizes, different shapes of steel member, then automatically climb, automatically detect and automatically arrange data by control center, finally realize the technical purpose of automatically evaluating the residual bearing capacity of the measured member, improve the accuracy and efficiency of in situ nondestructive corrosion detection.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of nondestructive testing, in particular to a kind of rusted steel structure in situ nondestructive testing device and method. BACKGROUND

[0002] Steel structure is widely used in various structures due to its material with the advantages of convenient construction, light weight, high strength, various section types, cost saving and reliable quality, however, the working environment of part of steel structure is relatively harsh, and the corrosion of part of steel structure must be evaluated and maintained. As the detection method of key steel components in service, nondestructive in situ testing is more and more concerned. Part of key components cannot be replaced or sampled in service, and it is difficult to achieve excellent corrosion detection and protection, which has potential risk of accident.

[0003] The prior art has the following problems in the in situ nondestructive testing of steel structure in service:

[0004] 1. The corrosion detection equipment for similar H-shaped steel components has insufficient compatibility and convenience, resulting in low detection efficiency and low precision.

[0005] 2. Most of the steel component corrosion detection methods use manual handheld detector, which is easy to miss defects and time-consuming and laborious.

[0006] 3. The corrosion detection work of part of steel components of bridge and high-rise building has high risk.

[0007] 4. The intuitiveness of the detection results of residual bearing capacity of corroded steel structure is poor. SUMMARY

[0008] In view of the problems of existing detection technology and device, the present application provides a kind of rusted steel structure in situ nondestructive testing device and method, the device is through bending fixed band, adjust the angle of connection fixed device to adapt to different size, different shape of steel component, then through control center automatic climbing, automatic detection and automatic data arrangement, finally realize automatic evaluation of the residual bearing capacity of the measured component, improve the accuracy and efficiency of in situ nondestructive corrosion detection.

[0009] In order to realize the above technical purpose, the technical scheme adopted by the present application is:

[0010] A kind of rusted steel structure in situ nondestructive testing device, comprising:

[0011] Fixed band, enclosed in the outer side of the steel structure to be measured, is a frame structure consistent with the shape of the steel structure to be measured;

[0012] A sensing belt is connected to the inner side of the fixing belt, and a longitudinal convex groove is arranged on the inner side of the sensing belt. A plurality of thickness detection sensors are uniformly arranged in the longitudinal convex groove along the groove length direction of the longitudinal convex groove, and the thickness detection sensors are used to detect the residual steel thickness data in the steel structure to be measured.

[0013] A position detection sensor is built in the sensing belt and is used to detect the horizontal position data of each thickness detection sensor.

[0014] A signal transmitter is used to transmit the residual steel thickness data and the horizontal position data of each thickness detection sensor to a data receiver.

[0015] A processing module is electrically connected to the signal input end of the data receiver and is connected to the climbing vehicle group through the signal output end.

[0016] A climbing vehicle group is connected to the outer side of the fixing belt, is adsorbed on the surface of the steel structure to be measured through a magnetic climbing wheel, and is used to drive the entire nondestructive testing device to climb or descend along the surface of the steel structure to be measured.

[0017] A first power module is arranged inside the sensing belt and provides power for the thickness detection sensor, the position detection sensor, the signal transmitter, and the processing module.

[0018] A second power module provides power for the climbing vehicle group.

[0019] The material of the fixing belt is a shape memory alloy, and the fixing belt includes a plurality of fixing belt units. The plurality of fixing belt units are connected through a first connecting piece to form a frame structure that is enclosed outside the steel structure to be measured and is consistent with the shape of the steel structure to be measured.

[0020] The sensing belt includes a plurality of sensing belt units, and the plurality of sensing belt units are connected through a second connecting piece. Data lines and power lines are pre-embedded in the sensing belt units. The data lines are electrically connected to the signal output end of the thickness detection sensor and the position detection sensor.

[0021] The end of the sensing belt unit is provided with a sensing belt data power jack / plug that is connected to the data lines and the power lines.

[0022] The sensing belt unit and the fixing belt unit are connected through a fastener.

[0023] The corner of the frame structure is connected through a corner connecting and fixing device between two sensing belt units.

[0024] The corner connecting and fixing device includes:

[0025] Two L-shaped steel plates, each of which has two rows of first strip-shaped holes arranged in parallel on one right-angle side, and two rows of second strip-shaped holes arranged in parallel on the other right-angle side;

[0026] The first strip-shaped holes between the adjacent right-angle sides of the two L-shaped steel plates are connected by the first bolts to adjust the distance to adapt to the thickness of different steel structures to be measured;

[0027] The second strip-shaped holes between the opposite right-angle sides of the two L-shaped steel plates are connected by the second bolts to adjust the distance to adapt to the width of different steel structures to be measured.

[0028] The climbing vehicle set comprises a main control box and two walking support parts symmetrically fixed to the upper and lower surfaces of the main control box,

[0029] The second power module is arranged in the main control box;

[0030] The two walking support parts are structurally identical and each comprises a plurality of L-shaped fixing claws fixed to the main control box, the end portions of the L-shaped fixing claws are connected to an axle, a magnetic climbing wheel is connected to the axle, a motor is connected to one side of the axle to provide power, and a disc brake device is connected to the other side of the axle to provide braking force.

[0031] One end of the L-shaped fixing claw is fixedly connected to the main control box, the other end is provided with a slide rail arranged in the supporting direction, the axle is connected to the slide rail, a spring is connected to the rear portion of the axle in the slide rail through a moving abutting block in the supporting direction, and the spring provides damping for the axle to improve the passability of the climbing vehicle set.

[0032] Horizontal slide grooves are arranged on the left and right sides of the main control box;

[0033] The fixed angle steel part has a horizontal support arm, one end of the horizontal support arm is slidably connected to the horizontal slide groove, and the other end of the horizontal support arm has a vertical support plate;

[0034] The vertical support plate is abutted against the fixed belt by adjusting the horizontal support arm to slide along the horizontal slide groove, and the vertical support plate and the fixed belt are fixed by fasteners;

[0035] The horizontal support arm and the horizontal slide groove are relatively fixed by the clamping knob on the upper surface of the main control box.

[0036] The thickness detection sensor is an ultrasonic sensor, the ultrasonic sensor is fixed in a through convex groove on the inner side of the sensing belt by a clamping screw, and the first power module is turned on when the clamping screw is fixed;

[0037] The signal transmitter is a wireless signal transmitter.

[0038] The climbing vehicle group comprises a plurality of main control boxes, and a wireless interconnection communication module is arranged in the main control box, which is used for signal interconnection of each climbing vehicle group to ensure that the overall device cooperates with climbing.

[0039] The application further discloses an installation method based on the device for in-situ nondestructive testing of a rusted steel structure.

[0040] S1, according to different working conditions, connecting the fixing belt unit into a required shape, fixing and connecting the sensing belt on the inner side of the fixing belt through fasteners, and connecting the corner connecting fixing device between two sensing belt units at the corner of the frame structure;

[0041] S2, according to the detection requirement, uniformly and interval arranging the thickness detection sensors in the through-length convex grooves on the sensing belt, and relatively fixing the thickness detection sensors and the sensing belt through clamping bolts;

[0042] S3, hanging the two walking support parts on the adjusting climbing vehicle group on the upper and lower sides of the fixing belt, adjusting the vertical support plate and the fixing belt through the fasteners by sliding the horizontal support arm along the horizontal sliding groove, relatively fixing the horizontal support arm and the horizontal sliding groove through the clamping knob on the upper surface of the main control box, and at this time, the magnetic climbing wheel at the end of the walking support part on the adjusting climbing vehicle group can be adsorbed to the surface of the steel structure to be detected.

[0043] The application further discloses a detection method based on the device for in-situ nondestructive testing of a rusted steel structure.

[0044] SA, starting the climbing vehicle group through the processing module, and driving the whole nondestructive testing device to climb or descend along the surface of the steel structure to be detected;

[0045] SB, detecting the horizontal position coordinate value X of the thickness detection sensor in the sensing belt through the position detection sensor, collecting the residual steel thickness data Z in the steel structure to be detected through the thickness detection sensor, calculating the coordinate value Y of the ultrasonic sensor through the climbing speed of the device, and converting the coordinate values X, Y and Z to obtain the three-dimensional point cloud coordinates of the steel structure to be detected if the corner automatically converts the coordinate values;

[0046] The signal transmitter is used for sending the three-dimensional point cloud coordinate data of the steel structure to be detected to the data receiver;

[0047] SC, data processing: the processor performs noise reduction and impurity removal on the three-dimensional point cloud coordinate data of the steel structure to be detected obtained from the data receiver;

[0048] Then, the obtained point cloud coordinates are reversely reconstructed by using three-dimensional model generation software to obtain a three-dimensional model with a rusted surface morphology.

[0049] Then the three-dimensional model is imported into the finite element analysis software to generate a solid model;

[0050] Finally, corrosion-related numerical analysis is performed in finite element software to obtain the residual bearing capacity of the steel structure to be tested and estimate its service life, providing a theoretical basis for subsequent repair and prevention.

[0051] Compared with existing equipment and technologies, the effective benefits of this invention are:

[0052] First, the present invention proposes an in-situ non-destructive testing device for corroded steel structures, which integrates automatic detection, climbing and data processing; automatically evaluates the in-service status of the corroded components being tested; automatically evaluates the residual bearing capacity of the components being tested, etc., thereby improving the efficiency and accuracy of corrosion detection and reducing the work risks of staff.

[0053] Secondly, the sensor belt and fixing belt of the present invention can be adapted to the current matching device modules due to the assembled equally spaced holes, and can also be designed and installed with other equipment according to the needs of later projects.

[0054] Third, the fixing belt of the present invention is made of shape memory alloy material, which can restore its original shape under a specific temperature or magnetic field, and can be bent to retain its shape, thereby achieving repeated use.

[0055] Fourthly, the fixing belt and the corner connection fixing device of the present invention can be adapted to steel members of different shapes in addition to H-shaped steel members of different sizes, and have strong compatibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 This is a schematic diagram of the overall structure of an in-situ nondestructive testing device for corroded steel structures according to the present invention;

[0057] Among them: 1. Fixing belt; 2. Sensor belt; 3. Climbing vehicle group; 4. Collection equipment; 5. Corner connection and fixing device; 6. Ultrasonic sensor; 44. Control system;

[0058] Figure 2 It is a structural schematic diagram of the fixing belt of the present invention;

[0059] Among them: 7. First equally spaced thread punching;

[0060] Figure 3 Schematic diagram of the structure of the sensor strip of the present invention;

[0061] Among them: 8, second equally spaced thread punching holes; 9, sensor belt data power interface; 10, sensor belt data power socket; 11, full-length convex groove;

[0062] Figure 4It is the view angle one structural schematic view of the climbing vehicle group of the present application;

[0063] Among them: 12, L type fixed claw; 13, wheel shaft; 14, fixed angle steel piece; 15, clamping knob;

[0064] Figure 5 It is the view angle two structural schematic view of the climbing vehicle group of the present application;

[0065] Among them, 16, main control box; 17, main control box switch; 18, fixed angle steel slide rail;

[0066] Figure 6 It is the structural schematic view of the magnetic climbing wheel on the climbing vehicle group of the present application;

[0067] Among them, 19, motor power supply pipeline; 20, motor; 21, disc brake device; 22, magnetic climbing wheel; 23, brake power supply pipeline;

[0068] Figure 7 It is the structural schematic view of the L type fixed claw on the climbing vehicle group of the present application;

[0069] 24, slide rail;

[0070] Figure 8 It is the structural schematic view of the fixed angle steel piece on the climbing vehicle group of the present application;

[0071] Among them, 25, groove; 26, third equidistant threaded hole;

[0072] Figure 9 It is the structural schematic view of the collecting equipment of the present application;

[0073] Among them: 27, telescopic cable; 28, data line interface; 29, fourth equidistant threaded hole; 30, collecting equipment switch; 31, collecting equipment usb interface; 32, notched slide rail;

[0074] Figure 10 It is the structural schematic view of the corner connecting fixing device of the present application;

[0075] Among them: 33, strip hole; 34, corner special bolt;

[0076] Figure 11 It is the structural schematic view of the ultrasonic sensor of the present application;

[0077] Among them: 35, clamping screw; 36, detector; 37, replaceable array type ultrasonic probe;

[0078] Figure 12 It is the control system schematic view;

[0079] Wherein: 38, joystick; 39, control system switch; 40, sensor belt access indicator; 41, climbing car group access indicator; 42, acquisition equipment access indicator; 43, equipment operable indicator;

[0080] Figure 13 is the detection schematic diagram of H-shaped steel working condition;

[0081] Figure 14 is the top view schematic diagram of H-shaped steel working condition detection;

[0082] Figure 15 is the flange and web surface coordinate matrix process;

[0083] Figure 16 is the coordinate point arrangement of the rusted surface;

[0084] Figure 17 is the schematic diagram of the cross section of the rusted plate;

[0085] Figure 18 is the schematic diagram of the three-dimensional surface geometry model of the rusted steel member;

[0086] Figure 19 is the schematic diagram of the corrosion degree representation method. DETAILED DESCRIPTION

[0087] The technical solutions of the present application will be further described in detail below in combination with the drawings of the specification and the specific embodiments.

[0088] Reference Figure 1-14 A kind of rusted steel structure in situ nondestructive testing device, including fixed band 1, sensor belt 2, climbing car group 3, acquisition equipment 4, corner connecting fixing device 5, ultrasonic sensor 6 and control system 44;The present application takes H-shaped steel member as an example, to avoid ultrasonic interference, take single face interval ultrasonic sensor arrangement as shown in Figure 14 .

[0089] Fixed band 1, for supporting sensor belt 2 and keeping the form of whole device when detecting, and buffering the vibration influence of climbing car group 3 to sensor belt 2, according to the bending of engineering demand, by clamping plate bolt connection.

[0090] Sensor belt 2, according to the bending of engineering demand, is placed in the inside of the fixed band, i.e. the detection direction, by the first equidistant screw hole 8, by screw rod connection;Sensor belt 2 is provided with through-length convex groove 11 along the length direction, for connecting ultrasonic sensor 6, sensor belt 2 is connected after starting ultrasonic sensor 6.

[0091] The climbing vehicle set 3 comprises a main control box 16 and walking support parts symmetrically fixed on the upper and lower surfaces of the main control box 16, and the two walking support parts are identical in structure and respectively comprise a plurality of L-shaped fixing claws 12 fixed on the main control box, the end portions of the L-shaped fixing claws 12 are connected with a wheel shaft, a magnetic climbing wheel 22 is connected with the wheel shaft, a motor 20 is connected with one side of the wheel shaft to provide power, and a disc brake device 21 is connected with the other side of the wheel shaft to provide braking force.

[0092] A slide rail 24 is arranged on the horizontal supporting arm of the L-shaped fixing claw 12 along the supporting direction, the wheel shaft is connected with the slide rail 24, a spring is connected with a moving abutting block along the supporting direction at the rear portion of the wheel shaft in the slide rail 24, and the spring provides certain damping effect to improve the passability of the vehicle set.

[0093] In order to make the magnetic climbing wheel 22 better adapt to the contact performance with the surface of the measured component, horizontal sliding grooves are respectively arranged on the left and right sides of the main control box 16; a fixed angle steel part has a horizontal supporting arm, one end of the horizontal supporting arm is slidingly connected in the horizontal sliding groove, and the other end of the horizontal supporting arm has a vertical supporting plate; the vertical supporting plate is abutted with the fixed belt by adjusting the horizontal supporting arm to slide along the horizontal sliding groove, and the vertical supporting plate and the fixed belt are fixed by fasteners;

[0094] The relative fixation between the horizontal supporting arm and the horizontal sliding groove is further achieved by the clamping knob 15 on the upper surface of the main control box 16.

[0095] Since the third equidistant threaded holes 26 of the fixed angle steel part 14 have the same spacing as the first equidistant threaded holes 7 on the fixed belt, bolts are reasonably arranged outside the fixed belt 1 according to engineering requirements; after starting, each climbing vehicle set 3 is automatically interconnected to ensure that the overall device cooperates to climb.

[0096] The collection device 4 is connected with the interface at the end of the sensing belt through a telescopic cable 27, the collection device 4 adopts a concave design, the width of the notch slide rail 32 is consistent with the sum of the thicknesses of the fixed belt 1 and the sensing belt 2, the notch slide rail 32 also has fourth equidistant threaded holes 29 adapted to the fixed belt 1, and the collection device 4 is fixed on the upper ends of the fixed belt 1 and the sensing belt 2 by bolts after the distance is adjusted; after starting, the detection data of the sensing belt is automatically received by the built-in receiver, and the initial detection data is preliminarily processed and integrated by the built-in integrated chip; when the detection is completed, the data can be automatically copied or transmitted through the USB interface 31.

[0097] The corner connecting and fixing device 5 comprises two L-shaped steel plates, each L-shaped steel plate has two rows of first strip-shaped holes arranged in parallel on one right angle edge; and two rows of second strip-shaped holes arranged in parallel on the other right angle edge.

[0098] The first bolt is connected in the first strip-shaped hole between the adjacent right-angle edges of the two L-shaped steel plates, and the distance is adjusted to adapt to the thickness of different components;

[0099] The second bolt is connected in the second strip-shaped hole between the opposite right-angle edges of the two L-shaped steel plates, and the distance is adjusted to adapt to the width of different components.

[0100] The ultrasonic sensor 6 comprises a detector 36 which is slidingly arranged in the through-length convex groove 11 of the sensing belt, and after being arranged according to engineering requirements, the sensing belt 2 supplies power to the detector 36 to start up after the clamping bolt 35 is tightened, the data collected by each detector 36 is transmitted to the sensing belt 2 through a wireless device, and the probe 37 of the ultrasonic sensor 6 can be replaced according to actual requirements.

[0101] The sensing belt 2 preliminarily determines the positions of the data collected by the ultrasonic sensors 6 at different positions;

[0102] When the sensing belt 2, the climbing vehicle group 3 and the collection equipment 4 are successfully started, the control system 44 will light up the corresponding green light, and the climbing and descending of the device are controlled through the joystick 38.

[0103] After the overall device is assembled and started, the climbing vehicle group 3 is controlled to climb through the control system 44, and if a bumpy area is encountered in the climbing process, the spring in the slide rail 24 can be used for filtering to ensure that the overall device runs stably.

[0104] The application further discloses a mounting method based on the device for in-situ nondestructive testing of a rusted steel structure.

[0105] S1, according to different working conditions, connecting the fixing belt units into a required shape, fixing and connecting the sensing belt on the inner side of the fixing belt through fasteners, and connecting the corner connecting fixing devices between two sensing belt units at the corner of the frame structure;

[0106] S2, according to detection requirements, uniformly and intervally arranging the ultrasonic sensors in the through-length convex grooves on the sensing belt, and relatively fixing the ultrasonic sensors and the sensing belt through clamping bolts;

[0107] S3, hanging the two walking support parts on the adjusting climbing vehicle group on the upper and lower sides of the fixing belt, sliding and adjusting the horizontal support arm along the horizontal sliding groove, fixing the vertical support plate and the fixing belt through fasteners, relatively fixing the horizontal support arm and the horizontal sliding groove through the clamping knobs on the upper surface of the main control box, and at this time, the magnetic climbing wheels at the ends of the walking support parts on the adjusting climbing vehicle group can be adsorbed to the surface of the steel structure to be detected.

[0108] The application further discloses a detection method based on the device for in-situ nondestructive detection of a rusted steel structure,

[0109] SA, the climbing vehicle group is started by the processing module, and the whole nondestructive detection device is driven to climb or descend along the surface of the steel structure to be detected;

[0110] SB, the horizontal position coordinate value X of the thickness detection sensor in the transmission belt is detected by the position detection sensor; the residual steel thickness data Z in the steel structure to be detected is collected by the thickness detection sensor; the coordinate value Y of the ultrasonic sensor is calculated by the climbing speed of the device; if the angle automatic conversion is used, the coordinate values X, Y and Z are converted, and the three-dimensional point cloud coordinates of the steel structure to be detected are obtained;

[0111] The three-dimensional point cloud coordinate data of the steel structure to be detected are sent to the data receiver by the signal transmitter;

[0112] SC, data processing: the three-dimensional point cloud coordinate data of the steel structure to be detected obtained from the data receiver are denoised and impurities are removed by the processor;

[0113] Then, the obtained point cloud coordinates are reversely reconstructed by using three-dimensional model generation software to obtain a three-dimensional model with a rusted surface morphology;

[0114] The three-dimensional model is imported into finite element analysis software to generate a solid model;

[0115] Finally, corrosion-related numerical analysis is performed in the finite element software, so that the residual bearing capacity of the steel structure to be detected is analyzed and the usable life is predicted, thereby providing a theoretical basis for subsequent repair and prevention.

[0116] The specific calculation method is as follows:

[0117] 1. The point cloud file obtained by scanning is imported into the reverse software Geomagic Studio to cut off other parts, and only the upper and lower surfaces for calculating the residual thickness are reserved.

[0118] 2. The upper and lower surfaces are matrixed by using surfer with 0.1 mm as a unit for the x coordinate and y coordinate of all points, and the x coordinate and y coordinate of the upper and lower surfaces are normalized, so that the x coordinate and y coordinate of the upper and lower surfaces are consistent, and the calculation of the residual thickness is facilitated, and the coordinate data of the upper and lower surfaces are saved as two dat files respectively.

[0119] 3. The thickness corresponding to each point in the parallel section of the test piece is calculated by using Matlab: as shown in the following formulas, Figure 15 and Figure 16 Taking S1 as an example, the cross-sectional area of the rusted plate is calculated by the following formula:

[0120]

[0121] S 1-i = (Z1-Z3+Z2-Z4)x2

[0122] Figure 16 wherein, M is the width of the measured steel member, N is the length of the measured steel member, S1-S N are the cross-sectional areas of each small part after dividing N parts along the length direction.

[0123] Figure 17 wherein, Z1, Z2, Z3, Z4 in the cross-sectional schematic diagram of the rusted plate member are the Z coordinate values of four vertexes of a small section, S1 is Figure 16 the partial area shown in part (a), S 1-i is the area of the black shaded part in the diagram, S 1-1 is the area of the white shaded part in the diagram, and S 1-M is the small cross-sectional area of each part after S1 is subdivided into M parts.

[0124] wherein, Δx1, Δx2 are the horizontal and vertical distances between points after standardization and matrix, and M, N represent the length and width of the upper and lower surfaces, and the values are determined according to the scanning accuracy.

[0125] I. Corrosion degree calculation

[0126] The corrosion degree calculation includes uniform corrosion rate and local corrosion rate:

[0127] 1. Uniform corrosion rate (D h ):

[0128] The local corrosion depth is defined as the distance d between the corrosion profile and the plane where the highest point of the corrosion profile is located, and the Z-axis coordinate value in the three-dimensional coordinates of the surface of each test piece is converted into the local corrosion depth d value.

[0129] S a represents the arithmetic mean height of the surface, which is defined as the arithmetic mean of the absolute values of the surface profile deviation

[0130] from the reference surface in the detection area:

[0131]

[0132] Quickly evaluate the uniform corrosion rate (D h ) of the measured rusted steel member:

[0133]

[0134] wherein, A is the area of the detection area, z(x, y) is the height coordinate of the surface micro-geometric morphology distribution point, and the coordinate system is based on the reference surface, (x i , y j)∈A, i=0,1,…M;j=0,1,…N;M,N are the number of sampling points in the detection area in X and Y directions respectively, H is the thickness of the uncorroded specimen; h is the maximum residual thickness.

[0135] 2. Local corrosion rate (η l ):

[0136] S p represents the maximum height of the surface peak, which is defined as the maximum height of the profile above the reference surface;

[0137] S v represents the maximum depth of the surface valley, which is defined as the maximum depth of the profile below the reference surface;

[0138] S z Indicates the maximum height of the surface, defined as S p With S v The sum of the values.

[0139] The formula is as follows:

[0140]

[0141] S z =S p +S v

[0142] From the definition of local corrosion depth in the previous article, we can know that the calculation formula of local corrosion depth is d(x,y)=S p -z(x,y). The average local corrosion depth can be deduced to be

[0143] And S z This is the maximum local corrosion depth.

[0144] By sorting out the experimental data, the maximum local corrosion depth S z With localized rust

[0145] The local corrosion rate (η l ):

[0146]

[0147] By calculating the goodness of fit determination coefficient R 2 =0.92119, it can be seen that the formula has a high degree of fit; where C2 is 78.445, the unit is μm, which is the S when the corrosion rate is 0%. z Mean.

[0148] According to the above theories and formulas, the uniform corrosion rate and local corrosion rate of the corroded steel components can be calculated and theoretical data can be provided for the evaluation of the degree of corrosion.

[0149] II. Residual load capacity calculation: SD, reverse reconstruction: The point cloud file obtained by the ultrasonic sensor is imported into the reverse reconstruction software Geomagic Studio, and the following operations are performed in the precise surface function module: a. Detect the surface curvature of the steel member, draw the member contour line; b. Construct a curved surface sheet (the purpose is to discretize each region into a plurality of small quadrilateral curved surface sheets, since each quadrilateral curved surface sheet will be responsible for presenting the surface characteristics of the region); c. Construct a grid to place a grid structure with a specified resolution in each curved surface sheet; d. When fitting the NURBS surface, the surface tension parameter is set to 0; e. Save the file in.igs format for subsequent import into Abaqus for residual load capacity analysis.

[0150] SE, residual load capacity calculation: In Abaqus, the specific operations are as follows: f. Parts: The.igs general format file can be directly imported into the finite element software as a part; g. Material properties: The material properties of various steel members need to be obtained according to the test report of the member to be tested or through material property testing; h. Meshing: Meshing in the pre-processing stage of ABAQUS can be used, but due to its limited meshing capability, if free meshing fails, meshing can be performed through the pre-processing software Hypermesh and the meshing quality can be controlled, and the directly exported. The.inp format file can be directly imported into Abaqus for analysis; i. Initial defects: The imported parts in the present application are based on the geometric parameters of the steel member itself, and the initial defects of the member are already included, so there is no need to repeat the input of the initial defects of the member; j. Boundary conditions and loads: This part needs to be applied according to the actual situation of the in-service steel member; k. Solution: The nonlinear buckling analysis of the specimen uses the Riks method, and the large deformation switch is turned on during calculation, and the residual load capacity of the residual steel is obtained.

Claims

1. An in-situ nondestructive testing device for corroded steel structures, characterized in that: include: The fixing belt is enclosed outside the steel structure to be tested and is a frame structure consistent with the shape of the steel structure to be tested; A sensing belt connected to the inner side of the fixing belt, wherein the inner side of the sensing belt is provided with a full-length convex groove, wherein a plurality of thickness detection sensors are evenly arranged in the full-length convex groove along the groove length direction, wherein the thickness detection sensors are used to detect the remaining steel thickness data in the steel structure to be measured; A position detection sensor, built into the sensing belt, for detecting horizontal position data of each thickness detection sensor; A signal transmitter, configured to transmit the remaining steel thickness data and the horizontal position data of each thickness detection sensor to a data receiver; a processing module, wherein a signal input end thereof is electrically connected to the data receiver, and a signal output end thereof is connected to the climbing vehicle assembly; The climbing vehicle assembly is connected to the outside of the fixing belt and is adsorbed on the surface of the steel structure to be tested through magnetic climbing wheels, and is used to drive the entire non-destructive testing device to climb or descend along the surface of the steel structure to be tested; a first power supply module, disposed inside the sensing strip, and providing power to the thickness detection sensor, the position detection sensor, the signal transmitter, and the processing module; The second power supply module provides power to the climbing vehicle assembly.

2. The in-situ nondestructive testing device for corroded steel structures according to claim 1, characterized in that: The fixing belt is made of shape memory alloy and includes a plurality of fixing belt units, which are connected by a first connector to form a frame structure that is enclosed outside the steel structure to be tested and has the same shape as the steel structure to be tested; The sensor strip includes a plurality of sensor strip units, which are connected to each other via a second connector. A data line and a power line are pre-buried inside the sensor strip units, and the data line is electrically connected to the signal output end of the thickness detection sensor and the position detection sensor. The end of the sensor belt unit is provided with a sensor belt data power supply interface / socket connected to the data line and the power line; The sensing belt unit and the fixing belt unit are connected via a fastener; The corner of the frame structure is located between the two sensor strip units and is connected via a corner connection fixture.

3. The in-situ nondestructive testing device for corroded steel structures according to claim 2, characterized in that: The corner connection and fixing device comprises: two L-shaped steel plates, each of which has two rows of first strip-shaped holes arranged in parallel in upper and lower directions on a right-angled side; Two rows of second strip-shaped holes arranged in parallel up and down are opened on the other right-angled side; Connected to the first strip hole between the adjacent right-angled sides of the two L-shaped steel plates by a first bolt, the distance is adjusted to adapt to the thickness of different steel structures to be tested; The second bolt is connected to the second strip hole between the opposite right-angled sides of the two L-shaped steel plates, and the distance is adjusted to adapt to the width of different steel structures to be measured.

4. The in-situ nondestructive testing device for corroded steel structures according to claim 3, characterized in that: The climbing vehicle assembly includes a main control box and two walking support parts symmetrically fixed on the upper and lower surfaces of the main control box, and the second power supply module is arranged in the main control box; The two walking support parts have the same structure and both include: a plurality of L-shaped fixing claws (12) fixed on a main control box (16); the ends of the L-shaped fixing claws (12) are commonly connected to a wheel axle (13); a magnetic climbing wheel (22) is connected to the wheel axle (13); one side of the wheel axle is connected to a motor to provide power, and the other side is connected to a disc brake device to provide braking force.

5. The in-situ nondestructive testing device for corroded steel structures according to claim 4, characterized in that: One end claw arm of the L-shaped fixed claw (12) is fixedly connected to the main control box, and the other end claw arm is provided with a slide rail (24) arranged along the supporting direction. The wheel axle (13) is connected to the slide rail (24). A spring is connected to the rear part of the wheel axle in the slide rail (24) along the supporting direction through a movable abutment block. The spring provides shock absorption for the wheel axle to improve the passability of the climbing vehicle group.

6. The in-situ nondestructive testing device for corroded steel structures according to claim 4, characterized in that: Horizontal slides are respectively provided on the left and right sides of the main control box; A fixed angle steel member having a horizontal support arm, one end of which is slidably connected to the horizontal slide groove, and the other end of which has a vertical support plate; The horizontal support arm is slidably adjusted along the horizontal slide groove so that the vertical support plate contacts the fixing belt, and the vertical support plate and the fixing belt are fixed by fasteners; The horizontal support arm and the horizontal slide groove are relatively fixed by a clamping knob on the upper surface of the main control box.

7. The in-situ nondestructive testing device for corroded steel structures according to claim 6, characterized in that: The thickness detection sensor is an ultrasonic sensor, which is fixed in a through-length convex groove on the inner side of the sensor strip by a clamping screw, and is connected to the first power module when the clamping screw is fixed; The signal transmitter is a wireless signal transmitter.

8. The in-situ nondestructive testing device for corroded steel structures according to claim 6, characterized in that: The climbing vehicle group includes multiple climbing vehicles, and the main control box has a built-in wireless interconnection communication module. The wireless interconnection communication module is used to interconnect the signals of the climbing vehicle groups to ensure the coordinated climbing of the entire device.

9. The method for installing the in-situ nondestructive testing device for corroded steel structures according to any one of claims 6 to 8, characterized in that: The following steps are involved: S1. Connect the fixing belt units into a desired shape according to different working conditions, and fix the sensor belt on the inner side of the fixing belt with fasteners. Connect the two sensor belt units at the corners of the frame structure with a corner connection fixture; S2. Arrange the thickness detection sensors evenly and spaced apart in the full-length convex grooves on the sensing belt according to detection requirements, and fix the thickness detection sensors and the sensing belt relatively with each other using clamping bolts; S3, hooking the two walking support parts on the adjustable climbing vehicle assembly to the upper and lower sides of the fixing belt, and sliding the horizontal support arm along the horizontal slide groove to fix the vertical support plate and the fixing belt with fasteners; The horizontal support arm and the horizontal slide are relatively fixed by the clamping knob on the upper surface of the main control box; at this time, the magnetic climbing wheel located at the end of the walking support part on the adjustment climbing vehicle group can be adsorbed with the surface of the steel structure to be tested.

10. A detection method based on the in-situ nondestructive testing device for corroded steel structures according to any one of claims 1 to 8, characterized in that: The following steps are involved: SA, start the climbing vehicle group through the processing module, and drive the entire non-destructive testing device to climb or descend along the surface of the steel structure to be tested; SB, using the position detection sensor to detect the horizontal position coordinate value X of the thickness detection sensor in the sensing belt; The thickness detection sensor is used to collect the remaining steel thickness data Z in the steel structure to be measured; the coordinate value Y of the ultrasonic sensor is calculated using the climbing speed of the device; if the angle is automatically converted, the coordinate values ​​of X, Y, and Z are converted to obtain the three-dimensional point cloud coordinates of the steel structure to be measured; Using a signal transmitter, the three-dimensional point cloud coordinate data of the steel structure to be measured is sent to a data receiver; SC, data processing: The processor reduces noise and removes impurities from the three-dimensional point cloud coordinate data of the steel structure to be measured obtained from the data receiver; The obtained point cloud coordinates are then reversely reconstructed using 3D model generation software to obtain a 3D model with the rusted surface morphology; Then the three-dimensional model is imported into the finite element analysis software to generate a solid model; Finally, corrosion-related numerical analysis is performed in finite element software to obtain the residual bearing capacity of the steel structure to be tested and estimate its service life, providing a theoretical basis for subsequent repair and prevention.

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