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

Abstract

The invention discloses an in-situ nondestructive testing device and method for a rusted steel structure, and the device comprises a plurality of fixing belts and a plurality of sensing belts which are enclosed at the outer side of a to-be-tested steel structure and are of a frame structure consistent with the to-be-tested steel structure in appearance; the outer side of the fixing belt is connected with the climbing vehicle group, and the inner side is connected with the sensing belt; the climbing vehicle group can drive the whole nondestructive testing device to climb or descend along the surface of the to-be-tested steel structure; and the acquisition equipment is used for collecting and preprocessing data of the sensing belt. According to the in-situ nondestructive testing device for the rusted steel structure, the fixing belt is bent, the corner connecting and fixing device is adjusted to adapt to steel members of different sizes and different shapes, then the control center automatically climbs, automatically detects and automatically arranges data, and finally the technical purpose of automatically evaluating the residual bearing capacity of the detected member is achieved. And the accuracy and efficiency of in-situ nondestructive corrosion detection are improved.

Description

Technical Field

[0001] The invention relates to the technical field of nondestructive testing, and in particular to an in-situ nondestructive testing device and method for a corroded steel structure. Background Art

[0002] Steel structures are widely used in various structures due to their advantages such as convenient construction, light weight and high strength, a wide variety of cross-sections, cost savings, and reliable quality. However, the working environment of some steel structures is relatively harsh, and some components of the steel structures must be evaluated and maintained for corrosion. Among them, non-destructive in-situ testing as a detection method for key steel components in service has received increasing attention. Some key components cannot be replaced or sampled while in service, making it difficult to achieve excellent corrosion detection and protection, and there is a potential risk of accidents.

[0003] The existing technology for in-situ nondestructive testing of in-service steel structures has the following problems:

[0004] 1. The compatibility and convenience of corrosion detection equipment suitable for H-shaped steel components are insufficient, resulting in low detection efficiency and low accuracy.

[0005] 2. For corrosion detection of steel components, most of the methods used are manual handheld detectors, which are easy to miss defects and are time-consuming and labor-intensive.

[0006] 3. For bridges and some steel components of high-rise buildings, corrosion inspection work is highly dangerous.

[0007] 4. The test results of the residual bearing capacity of rusted steel in rusted structures are less intuitive. Summary of the invention

[0008] In response to the problems of existing detection technologies and devices, the present invention proposes an in-situ non-destructive detection device and method for corroded steel structures. The device adapts to steel components of different sizes and shapes by bending the fixing belt and adjusting the corner connection fixing device. The device then automatically climbs, detects and organizes data through the control center, and finally automatically evaluates the remaining bearing capacity of the tested component, thereby improving the accuracy and efficiency of in-situ non-destructive corrosion detection.

[0009] In order to achieve the above technical objectives, the technical solution adopted by the present invention is:

[0010] An in-situ nondestructive testing device for a corroded steel structure, comprising:

[0011] The fixing belt is enclosed outside the steel structure to be tested and is a frame structure consistent with the appearance of the steel structure to be tested;

[0012] A sensing belt connected to the inner side of the fixing belt, wherein a through-length convex groove is provided on the inner side of the sensing belt, wherein a plurality of thickness detection sensors are evenly arranged in the through-length convex groove along the groove length direction of the through-length convex groove, wherein the thickness detection sensors are used to detect the remaining steel thickness data in the steel structure to be tested;

[0013] A position detection sensor, built into the sensing belt, for detecting horizontal position data of each thickness detection sensor;

[0014] A signal transmitter, used for sending the remaining steel thickness data and the horizontal position data of each thickness detection sensor to a data receiver;

[0015] A processing module, whose signal input end is electrically connected to the data receiver and whose signal output end is connected to the climbing vehicle group;

[0016] The climbing vehicle group 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, so as to drive the entire nondestructive testing device to climb or descend along the surface of the steel structure to be tested;

[0017] A first power module, disposed inside the sensor belt, for providing power to the thickness detection sensor, the position detection sensor, the signal transmitter and the processing module;

[0018] The second power supply module provides power to the climbing vehicle assembly.

[0019] The fixing belt is made of shape memory alloy, and includes a plurality of fixing belt units, which are connected by a first connecting piece to form a frame structure enclosed outside the steel structure to be tested and consistent with the shape of the steel structure to be tested;

[0020] The sensor belt includes a plurality of sensor belt units, and the plurality of sensor belt units are connected to each other through a second connecting member; a data line and a power line are pre-buried inside the sensor belt unit, and the data line is electrically connected to the signal output end of the thickness detection sensor and the position detection sensor;

[0021] The end of the sensor belt unit is provided with a sensor belt data power supply connector / socket connected to the data line and the power line;

[0022] The sensing belt unit and the fixing belt unit are connected by a fastener;

[0023] The corner of the frame structure is located between two sensor belt units and connected by a corner connection fixture.

[0024] The corner connection fixing device comprises:

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

[0026] Connected by a first bolt in a first strip hole between adjacent right-angle sides of two L-shaped steel plates, the distance is adjusted to adapt to the thickness of different steel structures to be tested;

[0027] The second bolt is connected to the second strip hole between the opposite right-angle 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.

[0028] 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.

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

[0030] The two walking support parts have the same structure, both comprising: a plurality of L-shaped fixing claws fixed on the main control box, the ends of the L-shaped fixing claws are commonly connected to the wheel axle, the wheel axle is connected to a magnetic climbing wheel, 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.

[0031] One end claw arm of the L-shaped fixed claw is fixedly connected to the main control box, and the other end claw arm is provided with a slide rail arranged along the supporting direction. The wheel axle is connected to the slide rail. The rear part of the wheel axle in the slide rail is connected with a spring through a movable abutment block along the supporting direction. The spring provides shock absorption for the wheel axle to improve the passability of the climbing vehicle group.

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

[0033] A fixed angle steel member, which has a horizontal support arm, one end of which is slidably connected in the horizontal slide groove, and the other end of which has a vertical support plate;

[0034] 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;

[0035] 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.

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

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

[0038] The climbing vehicle group includes multiple climbing vehicles, and the main control box has a built-in wireless interconnection communication module, which is used to interconnect the signals of the climbing vehicle groups to ensure the coordinated climbing of the entire device.

[0039] The present invention further discloses an installation method based on the in-situ nondestructive testing device for corroded steel structures, comprising the following steps:

[0040] S1. Connect the fixing belt unit into a desired shape according to different working conditions, fix the sensor belt on the inner side of the fixing belt by fasteners, and connect the two sensor belt units at the corner of the frame structure by a corner connection fixture;

[0041] S2. Arrange the thickness detection sensors evenly and spaced 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 by clamping bolts;

[0042] S3. Hang the two walking support parts on the adjusting climbing vehicle group on the upper and lower sides of the fixing belt, and slide and adjust the horizontal support arm along the horizontal slide groove so that 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 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 adjusting climbing vehicle group can be adsorbed on the surface of the steel structure to be tested.

[0043] The present invention provides a detection method based on the in-situ nondestructive detection device for corroded steel structures.

[0044] 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;

[0045] SB, using the position detection sensor to detect the horizontal position coordinate value X of the thickness detection sensor in the sensing belt; using the thickness detection sensor to collect the remaining steel thickness data Z in the steel structure to be measured; using the device climbing speed to calculate the coordinate value Y of the ultrasonic sensor; 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;

[0046] Using a signal transmitter, the three-dimensional point cloud coordinate data of the steel structure to be measured is sent to a 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 measured obtained from the data receiver;

[0048] Then the obtained point cloud coordinates are reversely reconstructed using 3D model generation software to obtain a 3D model with the 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 carried out 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 technology, the effective benefits of the present invention are:

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

[0053] Second, the sensor belt and the fixing belt of the present invention can not only adapt to the current matching device module, but also can be designed and installed with other equipment according to the later engineering requirements, because of the assembled and evenly spaced holes.

[0054] Thirdly, 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 realize the adaptation of steel members of different shapes other than H-shaped steel members of different sizes, and has strong compatibility. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

[0059] Among them: 7. First equally spaced threaded holes;

[0060] Figure 3 It is a schematic diagram of the structure of the sensor belt of the present invention;

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

[0062] Figure 4This is a perspective structural diagram of the climbing vehicle assembly of the present invention;

[0063] Among them: 12, L-shaped fixing claw; 13, axle; 14, fixing angle steel piece; 15, clamping knob;

[0064] Figure 5 is a structural schematic diagram of the climbing vehicle assembly of the present invention from a second perspective;

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

[0066] Figure 6 It is a schematic diagram of the structure of the magnetic climbing wheel on the climbing vehicle assembly of the present invention;

[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 a schematic diagram of the structure of the L-shaped fixing claw on the climbing vehicle assembly of the present invention;

[0069] 24. Slide rail;

[0070] Figure 8 It is a schematic diagram of the structure of the fixed angle steel member on the climbing vehicle assembly of the present invention;

[0071] Among them, 25, groove; 26, third equally spaced thread punching;

[0072] Fig. 9 It is a structural schematic diagram of the acquisition device of the present invention;

[0073] Among them: 27, retractable cable; 28, data line interface; 29, fourth equally spaced thread punching; 30, acquisition device switch; 31, acquisition device USB interface; 32, notched slide rail;

[0074] Fig.10 It is a schematic structural diagram of the corner connection fixing device of the present invention;

[0075] Among them: 33, strip-shaped holes; 34, special bolts for corners;

[0076] Fig.11 It is a schematic diagram of the structure of the ultrasonic sensor of the present invention;

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

[0078] Fig.12 It is a schematic diagram of the control system;

[0079] Among them: 38, joystick; 39, control system switch; 40, sensor belt access indicator; 41, climbing vehicle access indicator; 42, acquisition equipment access indicator; 43, equipment operational indicator;

[0080] Fig.13 This is a schematic diagram of detection under H-beam working conditions;

[0081] Fig.14 Schematic diagram of top view of detection under H-beam working condition;

[0082] Fig.15 The process of matrixing the flange and web surface coordinates;

[0083] Fig.16 Arrange the coordinate points of the rusted surface;

[0084] Fig.17 It is a schematic diagram of the cross section of the corroded plate;

[0085] Fig.18 The figure is a schematic diagram of the three-dimensional surface geometry model of the corroded steel component;

[0086] Fig.19 Schematic diagram of the corrosion degree characterization method. DETAILED DESCRIPTION

[0087] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0088] refer to Figure 1-14 , an in-situ nondestructive testing device for a corroded steel structure, comprising a fixing belt 1, a sensor belt 2, a climbing vehicle group 3, a collection device 4, a corner connection fixing device 5, an ultrasonic sensor 6 and a control system 44; the present invention takes an H-shaped steel member as an example, in order to avoid ultrasonic interference, a single-sided spaced ultrasonic sensor arrangement is adopted as follows Fig.14 shown.

[0089] The fixing belt 1 is used to support the sensor belt 2 and maintain the shape of the whole device during detection, as well as to buffer the vibration of the climbing vehicle group 3 on the sensor belt 2. It is bent according to engineering requirements and connected by clamping bolts.

[0090] The sensing belt 2 is bent according to engineering requirements and placed on the inner side of the fixing belt, i.e., in the detection direction, through the first equally spaced screw holes 8 and connected by a screw rod; the sensing belt 2 is provided with a through-length convex groove 11 along the length direction for connecting the ultrasonic sensor 6. After the sensing belt 2 is started, it waits for the connection of the ultrasonic sensor 6.

[0091] The climbing vehicle group 3 includes a main control box 16, and walking support parts symmetrically fixed on the upper and lower surfaces of the main control box 16. The two walking support parts have the same structure and respectively include: a plurality of L-shaped fixing claws 12 fixed on the main control box, the ends of the L-shaped fixing claws 12 are commonly connected to an axle, and a magnetic climbing wheel 22 is connected to the axle. One side of the axle is connected to a motor 20 to provide power, and the other side is connected to a disc brake device 21 to provide braking force.

[0092] A slide rail 24 is arranged on the horizontal support arm of the L-shaped fixing claw 12 along the supporting direction, and the wheel axle is connected to the slide rail 24. A spring is connected to the rear of the wheel axle in the slide rail 24 along the supporting direction through a movable abutment block, and the spring provides a certain shock-absorbing effect to improve the passability of the vehicle group.

[0093] In order to make the magnetic climbing wheel 22 better adapt to the contact performance with the surface of the measured component, the left and right sides of the main control box 16 are respectively provided with horizontal slide grooves; the fixed angle steel piece has a horizontal support arm, one end of the horizontal support arm is slidably connected in the horizontal slide groove, and the other end of the horizontal support arm has a vertical support plate; the horizontal support arm is slidably adjusted along the horizontal slide groove, so that the vertical support plate is in contact with the fixing belt, and the vertical support plate and the fixing belt are fixed by fasteners;

[0094] The horizontal support arm and the horizontal slide groove are relatively fixed by the clamping knob 15 on the upper surface of the main control box 16 .

[0095] Since the spacing of the third equally spaced threaded holes 26 of the fixed angle steel piece 14 is consistent with the first equally spaced threaded holes 7 on the fixing belt, it is reasonably placed on the outside of the fixing belt 1 through bolts according to engineering requirements; after starting, each climbing vehicle group 3 is automatically interconnected to ensure the coordinated climbing of the entire device.

[0096] The acquisition device 4 is connected to the interface 10 at the end of the sensor belt through a retractable cable 27. The acquisition device 4 adopts a concave design, and the width of its concave slide rail 32 is consistent with the sum of the thicknesses of the fixing belt 1 and the sensor belt 2. At the same time, it also has a fourth equally spaced threaded hole 29 adapted to the fixing belt 1. After adjusting the distance, it is fixed to the upper ends of the fixing belt 1 and the sensor belt 2 by bolts; after starting, it will automatically receive the detection data of the sensor belt through the built-in receiver, and preliminarily process and integrate the initial detection data through 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 connection fixing device 5 comprises two L-shaped steel plates, one right-angle side of each L-shaped steel plate is provided with two rows of first strip holes arranged in parallel in the upper and lower directions; the other right-angle side is provided with two rows of second strip holes arranged in parallel in the upper and lower directions;

[0098] Connected by first bolts in first strip holes between adjacent right-angle sides of two L-shaped steel plates, the distance is adjusted to adapt to the thickness of different components;

[0099] The second bolt is connected to the second strip hole between the opposite right-angle sides 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 includes a detector 36, which is slidably set in the full-length convex groove 11 of the sensor belt. After being arranged according to engineering requirements and tightening the clamping bolt 35, the sensor belt 2 will power on the detector 36 and start it. The data collected by each detector 36 will be transmitted to the sensor belt 2 via a wireless device; and the probe 37 of the ultrasonic sensor 6 can be replaced according to actual needs.

[0101] The sensor belt 2 will perform preliminary position determination on the data collected by the ultrasonic sensors 6 located at different positions;

[0102] When the sensor belt 2, the climbing vehicle group 3 and the acquisition device 4 are successfully started, the control system 44 will light up the corresponding green light and control the device to climb and descend through the joystick 38.

[0103] After the assembly and startup of the entire device is completed, the climbing vehicle group 3 is controlled to climb by the control system 44. If a bumpy area is encountered during the climbing process, it can be filtered by the spring in the slide rail 24 to ensure the smooth operation of the entire device.

[0104] The present invention further discloses an installation method based on the in-situ nondestructive testing device for corroded steel structures, comprising the following steps:

[0105] S1. Connect the fixing belt unit into a desired shape according to different working conditions, fix the sensor belt on the inner side of the fixing belt by fasteners, and connect the two sensor belt units at the corner of the frame structure by a corner connection fixture;

[0106] S2. Arrange the ultrasonic sensors evenly and spaced in the through-length convex grooves on the sensor belt according to detection requirements, and fix the ultrasonic sensors and the sensor belt relatively to each other by clamping bolts;

[0107] S3. Hang the two walking support parts on the adjusting climbing vehicle group on the upper and lower sides of the fixing belt, and slide and adjust the horizontal support arm along the horizontal slide groove so that 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 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 adjusting climbing vehicle group can be adsorbed on the surface of the steel structure to be tested.

[0108] The present invention further discloses a detection method based on the in-situ nondestructive detection device for corroded steel structures.

[0109] 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;

[0110] SB, using the position detection sensor to detect the horizontal position coordinate value X of the thickness detection sensor in the sensing belt; using the thickness detection sensor to collect the remaining steel thickness data Z in the steel structure to be measured; using the device climbing speed to calculate the coordinate value Y of the ultrasonic sensor; 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;

[0111] Using a signal transmitter, the three-dimensional point cloud coordinate data of the steel structure to be measured is sent to a data receiver;

[0112] 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 measured obtained from the data receiver;

[0113] Then the obtained point cloud coordinates are reversely reconstructed using 3D model generation software to obtain a 3D model with the rusted surface morphology;

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

[0115] Finally, corrosion-related numerical analysis is carried out 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.

[0116] The specific calculation method is as follows:

[0117] 1. Import the scanned point cloud file into the reverse engineering software Geomagic Studio to cut off other parts and keep only the upper and lower surfaces where the residual thickness needs to be calculated.

[0118] 2. Use Surfer to matrix and normalize the x and y coordinates of all points on the upper and lower surfaces in units of 0.1 mm. The purpose is to make the x and y coordinates of the upper and lower surfaces consistent to facilitate the subsequent calculation of residual thickness. Save the coordinate data of the upper and lower surfaces as two dat files respectively.

[0119] 3. And use Matlab to calculate the thickness of each point in the parallel section of the specimen: Fig.15 and Fig.16 As shown, taking S1 as an example, the cross-sectional area of ​​the corroded plate is calculated by the following formula:

[0120]

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

[0122] Fig.16 In the figure, M is the width of the steel piece being tested, N is the length of the steel piece being tested, S1-S N It is the cross-sectional area of ​​each small part after dividing it into N parts along the length direction.

[0123] Fig.17 In the cross-sectional diagram of the corroded plate, Z1, Z2, Z3, and Z4 are the Z coordinate values ​​of the four vertices of a small micro-segment measured, and S1 is Fig.16 The area of ​​the part shown in 1-i is the area of ​​the black shaded part in the figure, S 1-1 To S 1-M It is the small cross-sectional area of ​​each part after S1 is subdivided into M parts.

[0124] Among them, Δx1 and Δx2 are the horizontal and vertical spacing between points after normalization and matrixing, and M and N represent the length and width of the upper and lower surfaces, and the values ​​are determined according to the scanning accuracy.

[0125] 1. Calculation of corrosion degree

[0126] The calculation of the degree of corrosion is divided into two aspects: 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. The Z-axis coordinate value in the three-dimensional coordinates of the surface of each specimen is converted into the local corrosion depth d value.

[0129] S a It represents the arithmetic mean height of the surface, which is defined as the surface contour deviation within the detection area.

[0130] The arithmetic mean of the absolute values ​​from the reference surface:

[0131]

[0132] Rapid evaluation of the uniform corrosion rate (D h ):

[0133]

[0134] Where A is the area of ​​the detection area, z(x,y) is the height coordinate of the surface micro-geometric distribution point, and the coordinate system is set based on the reference surface. 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, 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 local corrosion

[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; C2 is 78.445, the unit is μm, which is 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] 2. Calculation of residual bearing capacity: SD, reverse reconstruction: The point cloud file obtained by the ultrasonic sensor is imported into the Geomagic Studio reverse reconstruction software, and the following operations are performed in the precise surface function module: a. Detect the surface curvature of the steel component and draw the component contour line; b. Construct surface patches (the purpose is to discretize each area into multiple small quadrilateral surface patches, because each quadrilateral surface patch will be responsible for presenting the surface characteristics of the area); c. Construct a grid to place a grid structure of specified resolution in each surface patch; 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 bearing capacity analysis.

[0150] SE. Calculation of residual bearing capacity: The specific operations in Abaqus are as follows: f. Components: .igs general format files can be directly imported into the finite element software as components; g. Material properties: The material properties of various steel components need to be obtained based on the test report of the component to be tested or through material properties tests; h. Meshing: The meshing in the pre-processing stage of ABAQUS can be used, but due to its limited meshing capabilities, if the free meshing fails, the pre-processing software Hypermesh can be used for meshing and the meshing quality can be controlled. The directly exported .inp format file can be directly imported into Abaqus for analysis; i. Initial defects: The components imported in the present invention are based on the geometric parameters of the steel components themselves, and the initial defects of the components are already included, so there is no need to repeatedly input the initial defects of the components; j. Boundary conditions and loads: This part needs to be applied based on the actual situation of the in-service steel components; k. Solution: The nonlinear buckling analysis of the specimen adopts the Riks method. The large deformation switch is turned on during the calculation to obtain the residual bearing capacity of the remaining steel.

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 appearance of the steel structure to be tested; A sensing belt connected to the inner side of the fixing belt, wherein a through-length convex groove is provided on the inner side of the sensing belt, wherein a plurality of thickness detection sensors are evenly arranged in the through-length convex groove along the groove length direction of the through-length convex groove, wherein the thickness detection sensors are used to detect the remaining steel thickness data in the steel structure to be tested; A position detection sensor, built into the sensing belt, for detecting horizontal position data of each thickness detection sensor; A signal transmitter, used for sending the remaining steel thickness data and the horizontal position data of each thickness detection sensor to a data receiver; A processing module, whose signal input end is electrically connected to the data receiver and whose signal output end is connected to the climbing vehicle group; The climbing vehicle group 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, so as to drive the entire nondestructive testing device to climb or descend along the surface of the steel structure to be tested; A first power module, disposed inside the sensor belt, for 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 structure 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 connecting piece to form a frame structure enclosed outside the steel structure to be tested and consistent with the shape of the steel structure to be tested; The sensor belt includes a plurality of sensor belt units, and the plurality of sensor belt units are connected to each other through a second connecting member; a data line and a power line are pre-buried inside the sensor belt unit, 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 connector / socket connected to the data line and the power line; The sensing belt unit and the fixing belt unit are connected by a fastener; The corner of the frame structure is located between two sensor belt units and connected by a corner connection fixture.

3. The in-situ nondestructive testing device for corroded steel structure according to claim 2, characterized in that: The corner connection fixing device comprises: Two L-shaped steel plates, each of which has two rows of first strip holes arranged in parallel up and down on one right-angled side; and two rows of second strip holes arranged in parallel up and down on the other right-angled side; Connected by a first bolt in a first strip hole between adjacent right-angle sides of two L-shaped steel plates, 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-angle 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 structure 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. The second power supply module is arranged in the main control box; The two walking support parts have the same structure, and both comprise: a plurality of L-shaped fixing claws (12) fixed on a main control box (16), the ends of the L-shaped fixing claws (12) being commonly connected to a wheel axle (13), a magnetic climbing wheel (22) being connected to the wheel axle (13), one side of the wheel axle being connected to a motor to provide power, and the other side being connected to a disc brake device to provide braking force.

5. The in-situ nondestructive testing device for corroded steel structure 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), and 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, and 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 structure according to claim 4, characterized in that: Horizontal slide grooves are respectively provided on the left and right sides of the main control box; A fixed angle steel member, which has a horizontal support arm, one end of which is slidably connected in 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 structure according to claim 1, 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 belt 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 structure 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, which is used to interconnect the signals of the climbing vehicle groups to ensure the coordinated climbing of the entire device.

9. The installation method for 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 unit into a desired shape according to different working conditions, fix the sensor belt on the inner side of the fixing belt by fasteners, and connect the two sensor belt units at the corner of the frame structure by a corner connection fixture; S2. Arrange the thickness detection sensors evenly and spaced 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 by clamping bolts; S3. Hang the two walking support parts on the adjusting climbing vehicle group on the upper and lower sides of the fixing belt, and slide and adjust the horizontal support arm along the horizontal slide groove so that 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 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 adjusting climbing vehicle group can be adsorbed on 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, 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; using the thickness detection sensor to collect the remaining steel thickness data Z in the steel structure to be measured; using the device climbing speed to calculate the coordinate value Y of the ultrasonic sensor; 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 performs noise reduction and impurity removal on the three-dimensional point cloud coordinate data of the steel structure to be measured obtained from the data receiver; Then the obtained point cloud coordinates are 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 carried out 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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