Welding seam detection method, medium and system for welding of floating ship plate of oil storage tank

Abstract

The invention provides a welding seam detection method, medium and system for welding of a floating ship plate of an oil storage tank, belongs to the technical field of electric digital data processing, and realizes comprehensive and accurate monitoring through six key matrixes. The method comprises the following steps: starting from a floating ship plate motion characteristic matrix, accurately capturing height, attitude and weld joint displacement data, establishing a comprehensive detection matrix containing ultrasonic flaw detection, X-ray imaging and surface topography through a multi-source detection technology, and comprehensively depicting weld joint microscopic characteristics. Dynamic stress-strain analysis is deeply carried out, a complex stress field distribution model considering floating influence is constructed, multi-dimensional feature matrixes are combined through weights to form a weld quality comprehensive evaluation matrix, and a self-adaptive detection parameter updating mechanism is established. And finally, a welding seam state vector and a safety threshold matrix are constructed, real-time monitoring and early warning are achieved, and the technical problems that in the prior art, only the internal quality of the welding seam can be statically evaluated, and the actual stress-strain state of the welding seam under the dynamic working condition cannot be comprehensively reflected are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of electric digital data processing, and in particular relates to a weld detection method, a medium and a system for welding a petroleum storage tank floating ship plate. Background Art

[0002] Floating storage tanks are widely used in offshore oil production and storage, and are one of the key equipment to ensure the efficient use of marine oil resources. This type of floating storage tank usually consists of a cylindrical pontoon and an oil storage tank inside it. The function of the pontoon is to provide buoyancy support for the oil storage tank, ensuring that the entire tank system can float stably on the sea surface. Compared with fixed storage tanks, floating storage tanks have higher adaptability and flexibility, and can cope with complex marine environmental conditions.

[0003] However, during the long-term operation at sea, the structure of floating storage tanks is severely impacted by external forces such as waves, wind and currents, resulting in various deformations and damages to the floating deck, which ultimately affects the service life and safety of the entire tank. The weld connection parts on the floating deck are the key parts most prone to problems. Due to the complex external dynamic loads, these welds are prone to failures such as fracture and cracking, and may even cause serious environmental pollution accidents. Therefore, how to effectively detect and evaluate the quality status of floating tank welds and detect abnormal conditions in a timely manner has become a technical problem that needs to be solved urgently.

[0004] In response to the above problems, the industry has proposed some existing detection methods, such as ultrasonic flaw detection, X-ray imaging and other means to perform conventional non-destructive testing on welds. However, these methods can usually only statically evaluate the internal quality of the weld and cannot fully reflect the actual stress-strain state of the weld under dynamic conditions. In addition, the existing detection methods also have problems such as unreasonable parameter settings, low detection accuracy, and inability to achieve real-time monitoring. Therefore, there is an urgent need for a new type of weld detection method that can comprehensively analyze the dynamic mechanical behavior of the weld and realize adaptive parameter optimization and real-time early warning functions, thereby improving the safety and reliability of the entire tank system. Summary of the invention

[0005] In view of this, the present invention provides a weld detection method, medium and system for welding of petroleum storage tank floating plates, which can solve the technical problem that the existing technology can usually only statically evaluate the internal quality of the weld and cannot fully reflect the actual stress and strain state of the weld under dynamic conditions.

[0006] The present invention is achieved in that: A first aspect of the present invention provides a method for detecting a weld seam of a petroleum storage tank floating plate welding, comprising the following steps: S10, constructing a floating board motion characteristic matrix, including: collecting a height matrix of the floating board, recording real-time height data of measuring points at different positions; establishing a floating board attitude matrix, including pitch angle, roll angle, yaw angle and velocity components in three directions; obtaining a relative displacement matrix of the circumferential weld and the radial weld during the floating process of the floating board; S20, collecting the basic detection matrix of the weld, including: establishing an ultrasonic flaw detection feature matrix to record the ultrasonic reflection coefficient at different positions and different detection angles; constructing an X-ray imaging feature matrix to obtain the X-ray penetration at different positions and different exposure parameters; forming a weld surface morphology feature matrix, including weld contour and surface defect distribution information; S30, perform dynamic stress-strain analysis: establish a stress matrix including normal stress and shear stress components; construct a strain matrix including normal strain and shear strain components; calculate the stress field distribution considering the floating effect through the stress-strain correlation equation group; S40. Construct a comprehensive evaluation matrix for weld quality: perform weighted combination of ultrasonic flaw detection feature matrix, X-ray imaging feature matrix and stress-strain matrix; establish a weight coefficient matrix to ensure a reasonable proportion of various indicators; and form an evaluation matrix that reflects the overall quality status of the weld; S50, realizing adaptive adjustment of detection parameters: establishing a detection parameter matrix including ultrasonic angle, X-ray parameters and strain acquisition parameters; constructing a parameter update equation based on the weld quality evaluation matrix; realizing dynamic optimization and update of detection parameters; S60. Perform real-time monitoring and early warning: construct a weld state vector, including integrity indicators, stress concentration indicators and fatigue damage indicators; set a safety threshold matrix and establish early warning trigger conditions; realize real-time monitoring of the weld state and abnormal early warning.

[0007] The stress-strain correlation equation group includes a principal stress calculation equation, a shear stress calculation equation, a strain distribution equation, and a fatigue damage accumulation equation; The principal stress calculation equation is used to calculate the magnitude and direction of the principal stress at each point of the weld. The input includes the weld position coordinates, the height data of the floating ship plate, the attitude angle data and the velocity component. The output is the magnitude and direction of the principal stress at each measuring point. The shear stress calculation equation is used to determine the shear stress distribution of the weld, the input includes principal stress data, weld relative displacement data and material shear modulus, and the output is the shear stress component of each point of the weld and the maximum shear stress position; The strain distribution equation is used to calculate the deformation state of the weld, the input includes principal stress data, shear stress data, material elastic modulus and Poisson's ratio, and the output is the normal strain and shear strain distribution of the weld area; The fatigue damage accumulation equation is used to evaluate the fatigue state of the weld, and the input includes the number of stress cycles, stress amplitude, average stress and material fatigue parameters, and the output is the fatigue damage degree of each point of the weld; The parameter update equation is used to optimize the detection parameter setting. The input includes the current detection parameters, weld quality evaluation indicators, detection accuracy requirements and equipment performance constraints. The output is the updated ultrasonic incident angle, X-ray exposure parameters and strain acquisition frequency.

[0008] The calculation process involved in the present invention is described in detail as follows: 1. The characteristic matrix of the floating plate motion is expressed as follows: ; In the formula, Indicates The measurement point is The altitude value at the moment, in meters, is the number of measurement points, is the number of sampling moments; The posture matrix is ​​expressed as follows: ; In the formula, is the pitch angle, and the range is ; is the roll angle, and the range is ; is the yaw angle, and the range is ; are the velocity components in three directions, in meters per second; The relative displacement matrix is ​​expressed as follows: ; In the formula, is the relative displacement vector of the circumferential weld, is the radial weld relative displacement vector; 2. The principal stress calculation equation is expressed as follows: ; In the formula, is the stress in the x direction, is the stress in the y direction, is the shear stress, is the oil density, is the acceleration due to gravity, is the liquid level height, is the attitude influence coefficient, is the dynamic viscosity; Indicates principal stress: The subscripts 1 and 2 here represent two principal stress values. is the maximum principal stress, is the minimum principal stress, which is the normal stress at a specific point when the coordinate system is rotated to the appropriate direction and the shear stress is zero.

[0009] Item 1 is the average normal stress, reflecting the average stress level in the two main directions; Item 2 is the maximum shear stress, which characterizes the degree of shear deformation; in: In the item, is the hydrostatic pressure term, is the posture correction item; The structure is the same as above, but the coefficients are different to reflect the anisotropy; is the shear stress caused by velocity; 3. The shear stress calculation equation is expressed as follows: ; In the formula, is the shear modulus, is the shear strain, is the viscosity coefficient, is the coefficient of the second-order derivative term; Item 1 is the static shear stress, reflecting the elastic deformation of the material; Item 2 is the viscous stress, describing the effect of strain rate; Item 3 and the fourth item is the spatial second-order derivative term, reflecting the propagation effect of strain; 4. The strain distribution equation is expressed as follows: ; In the formula, is the elastic modulus, is Poisson's ratio, ; are the components of the stress tensor, is a subscript indicating the stress direction, with values ​​of 1, 2, or 3. The first subscript i represents the normal direction of the stress surface, and the second subscript j represents the direction of the stress. represents the stress component in direction 2 on the surface perpendicular to direction 1; Represent the trace of the stress tensor: The repeated occurrence of k means that we need to sum k=1,2,3: ; It represents the sum of the normal stress components; is the Kronecker symbol, when i=j, , when i≠j, , used to represent tensor operations in the strain equation; Item 1 is the positive strain component; Item 2 is the lateral deformation coupling term; and Contact: is through The calculated eigenvalues; the principal stress calculation equation will be ( ), ( )and ( ) is converted to principal stress , this conversion actually finds the principal axis direction of the stress state, so that there is only normal stress in this direction and no shear stress; under the plane stress state, the principal stress calculation formula is given in the article: ; The physical meaning of this conversion is: for the stress state of any point, you can always find a specific coordinate system so that in this coordinate system, the point only bears normal stress (tension or compression) without shear. The direction of this coordinate system is the principal stress direction, and the corresponding normal stress value is the principal stress value.

[0010] 5. The fatigue damage accumulation equation is expressed as follows: ; In the formula, is the actual number of cycles, is the fatigue life, is the injury index, is the correction factor, is the stress amplitude, is the fatigue limit, is the material constant; Item 1 is the damage accumulation term of cycles; Item 2 is the stress amplitude damage accumulation term; 6. The parameter update equation is expressed as follows: ; In the formula, is the current parameter vector, is the learning rate, is the performance indicator function, is the second-order derivative weight, is a random disturbance term.

[0011] Item 1 is the current parameter value; Item 2 is the first-order gradient correction term; Item 3 is the second-order gradient correction term; Item 4 is a random disturbance term.

[0012] The parameter acquisition method is as follows: 1. Obtained through oil density meter measurement, the measurement temperature is , measure at least 3 times and take the average value; 2. Use the local gravity acceleration value, which can be obtained by measuring with a gravimeter; 3. Obtained through real-time measurement of the level meter, with a sampling frequency of no less than ; 4. Obtained through finite element analysis and experimental data fitting: Step 1: Establish a finite element model of the floating slab; Step 2: Apply different attitude angle conditions; Step 3: Extract stress data; Step 4: Use the least squares method to fit and obtain the coefficients; 5. Obtained by measuring with a rotational viscometer, measuring temperature range ,interval ; 6. Through material tensile testing, we can obtain: Step 1: Prepare standard samples; Step 2: Conduct a tensile test; Step 3: Calculate according to the stress-strain curve; 7. Measured by dynamic mechanical analyzer, test frequency range ; 8. Through wave propagation experiments, we obtain: Step 1: Apply transient load; Step 2: Measure the strain propagation velocity; Step 3: Inversely solve to obtain coefficients; 9. Obtained through standard material mechanical properties test; 10. Obtained through fatigue testing: Step 1: Conduct a constant amplitude fatigue test; Step 2: Record the number of fracture cycles; Step 3: Determine the index using regression analysis; 11. Determined through comparative tests: Step 1: Conduct variable amplitude fatigue test; Step 2: Measure actual lifespan; Step 3: Determine the correction factor by comparing with theoretical calculation; 12. Determined through optimization algorithm performance testing: Step 1: Set the initial value; Step 2: Conduct convergence test; Step 3: Select the optimal parameter combination.

[0013] Explanation of the above equation: 1. The principal stress calculation equation uses quadratic terms to describe the effect of attitude angle on stress, taking into account the unique motion characteristics of the floating plate. This is because the effect of attitude change on stress has nonlinear characteristics; 2. The second-order derivative terms of time and space are introduced into the shear stress calculation equation, which takes into account the propagation characteristics of strain and boundary effects; 3. The strain distribution equation is based on the generalized Hooke's law and takes into account the coupling effect under three-dimensional stress state; 4. The fatigue damage accumulation equation adopts a power function relationship, which is consistent with the nonlinear accumulation characteristics of material fatigue damage; 5. The parameter update equation combines the characteristics of gradient descent and Newton's method, which not only ensures the convergence speed but also improves the optimization accuracy.

[0014] A second aspect of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores program instructions, and when the program instructions are executed in a computer, they are used to execute the above-mentioned weld detection method for welding of a petroleum storage tank floating plate.

[0015] A third aspect of the present invention provides a weld detection system for welding of a petroleum storage tank floating plate, which includes the above-mentioned computer-readable storage medium.

[0016] Compared with the prior art, the weld detection method, medium and system for welding of oil storage tank floating plates provided by the present invention have the following beneficial effects: Firstly, the method constructs the motion characteristic matrix of the floating plate, including the height matrix, attitude matrix and relative displacement matrix, which fully describes the dynamic deformation characteristics of the floating plate under complex sea conditions. This provides the necessary basic data for the subsequent stress-strain analysis and greatly improves the accuracy and reliability of the detection results.

[0017] Secondly, this method uses matrix operations to replace the traditional data processing process. This not only improves the calculation efficiency, but also facilitates the comprehensive integration of the results of various detection methods. At the same time, this method establishes a group of stress-strain correlation equations, realizes the accurate analysis of the dynamic mechanical behavior of the weld, and lays a solid theoretical foundation for the comprehensive evaluation of weld quality.

[0018] In addition, this method realizes adaptive adjustment of detection parameters. By dynamically optimizing key parameters such as ultrasonic angle, X-ray exposure, and strain acquisition frequency, it ensures the optimal performance of various detection methods and greatly improves the detection accuracy.

[0019] Finally, the method has real-time monitoring and early warning functions, which can continuously monitor key indicators such as weld integrity, stress concentration, and fatigue damage, and immediately issue an early warning once an abnormal situation is found. This greatly improves the safety and reliability of the entire tank system and provides a strong guarantee for the efficient use of offshore oil resources.

[0020] In general, the weld detection method of the present invention fully considers the unique dynamic working conditions of floating storage tanks, adopts advanced matrix analysis and parameter optimization technology, realizes comprehensive evaluation and real-time monitoring of weld quality, and has made significant technical progress in improving detection accuracy and safety. It solves the technical problem that the existing technology can usually only statically evaluate the internal quality of the weld and cannot fully reflect the actual stress and strain state of the weld under dynamic conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A flow chart of the method provided by the present invention. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the embodiments of the present invention more clear, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0023] like Figure 1 As shown, it is a flow chart of a weld detection method for welding a petroleum storage tank floating plate provided by the present invention. The specific implementation method of each step is described in detail below: First, for step S10, it is necessary to construct the motion feature matrix of the floating board. This includes: Height Matrix : ; in, Indicates The measurement point is The altitude value at the moment, in meters; is the number of measuring points, is the number of sampling moments. By analyzing the height matrix, we can understand the displacement change of the floating board in the vertical direction.

[0024] Pose Matrix : ; in, is the pitch angle, the range is ; is the roll angle, and the range is ; is the yaw angle, and the range is ; They are the velocity components in three directions, in meters per second. The matrix reflects the attitude changes and motion characteristics of the floating board in the horizontal and vertical directions.

[0025] Relative displacement matrix : ; in, is the relative displacement vector of the circumferential weld, is the radial weld relative displacement vector. By analyzing these relative displacement data, we can understand the deformation of the weld in different directions.

[0026] In general, step S10 constructs the motion characteristic matrix of the floating plate, providing necessary basic data for subsequent weld detection.

[0027] Next, for step S20, it is necessary to collect the basic detection matrix of the weld. This includes: Ultrasonic flaw detection feature matrix: The matrix records the ultrasonic reflection coefficient data at different positions and detection angles. By analyzing these data, the defects and discontinuities inside the weld can be understood.

[0028] X-ray imaging feature matrix: The matrix obtains X-ray penetration data at different positions and exposure parameters. By analyzing this data, the overall quality of the weld can be understood, including internal defects, pores, etc.

[0029] Weld surface morphology feature matrix: The matrix contains the weld profile information and surface defect distribution. By analyzing these data, the appearance characteristics of the weld can be understood, providing a basis for subsequent comprehensive evaluation.

[0030] By collecting the weld feature matrix obtained by these three different detection methods, we can fully understand the information on the internal quality, surface quality, deformation characteristics, etc. of the weld, providing the necessary basic data for subsequent stress-strain analysis and comprehensive evaluation.

[0031] Next, for step S30, dynamic stress-strain analysis needs to be performed. This includes: Construction of stress matrix: The stress matrix contains normal stress components and shear stress components. These stress data are obtained according to the height matrix obtained in step S10 , attitude matrix And the relative displacement matrix , obtained through the principal stress calculation equation: ; in, is the stress in the x direction, is the stress in the y direction, is the shear stress. is the oil density, is the acceleration due to gravity, is the liquid level height, is the attitude influence coefficient, is the dynamic viscosity. This equation takes into account the influence of the hydrostatic pressure, attitude angle and movement speed of the floating plate on the stress, and can accurately reflect the stress state of the weld.

[0032] Construction of strain matrix: The strain matrix contains normal strain components and shear strain components. These strain data are calculated by the strain distribution equation based on the stress matrix and material mechanical properties parameters obtained above: ; in, is the elastic modulus, is Poisson's ratio, is the Kronecker symbol, The equation is based on the generalized Hooke's law and takes into account the coupling effect of strain under three-dimensional stress state.

[0033] Application of stress-strain correlation equations: Further, with the help of stress-strain correlation equations, the stress field distribution considering the floating effect is calculated. These include: Principal stress calculation equation: same as above Shear stress calculation equation: ; Strain distribution equation: same as above Fatigue damage accumulation equation: ; These equations fully consider the unique motion characteristics of the floating slab and provide an important basis for subsequent comprehensive evaluation.

[0034] In general, step S30 achieves accurate analysis of the dynamic stress-strain state of the weld by establishing a stress matrix and a strain matrix and combining a set of stress-strain correlation equations.

[0035] Next, for step S40, it is necessary to construct a comprehensive evaluation matrix for weld quality. This includes: Weighted combination of feature matrices: The ultrasonic flaw detection feature matrix obtained in step S20, the X-ray imaging feature matrix, and the stress-strain matrix obtained in steps S301 and S302 are weightedly combined to reflect the importance of different detection methods for weld quality evaluation: ; in, Represent the characteristic matrices of ultrasonic flaw detection, X-ray imaging and stress-strain, respectively. is the corresponding weight coefficient, satisfying .

[0036] Determination of weight coefficient matrix: Create a weight coefficient matrix , to ensure that each indicator has a reasonable proportion in the comprehensive evaluation. For example, you can set , making ultrasonic testing account for 40%, X-ray imaging account for 30%, and stress strain account for 30%. By adjusting these weight coefficients, the weight distribution of evaluation indicators can be flexibly determined according to different application scenarios and detection requirements.

[0037] Formation of comprehensive evaluation matrix: Finally, an evaluation matrix reflecting the overall quality status of the weld is formed The matrix comprehensively considers multiple factors such as weld internal defects, appearance quality and mechanical properties, and gives an overall quality evaluation result.

[0038] In general, step S40 constructs a comprehensive evaluation matrix, and obtains an evaluation result that comprehensively reflects the quality status of the weld by weighted combination of feature data of different detection methods, which lays the foundation for subsequent adaptive adjustment and real-time monitoring.

[0039] Next, for step S50, it is necessary to implement adaptive adjustment of detection parameters, including: Establishment of detection parameter matrix: Establish a detection parameter matrix including ultrasonic angle, X-ray parameters and strain acquisition parameters These parameters determine the measurement accuracy and effectiveness of various detection methods.

[0040] Construction of parameter update equation: Based on the weld quality evaluation matrix obtained in step S40 , construct the following parameter update equation: ; in, is the current parameter vector, is the learning rate, is the performance index function (i.e. ), is the second-order derivative weight, is the random disturbance term. This equation combines the characteristics of the gradient descent method and the Newton method, which not only ensures the convergence speed but also improves the optimization accuracy. Through continuous iterative updates, a set of optimal detection parameter settings can be found to ensure the accuracy of the evaluation results.

[0041] Explanation of parameter update process: The parameter update equation consists of four terms: Item 1 is the current parameter value; Item 2 is the first-order gradient correction term, used to adjust the direction of the parameters; Item 3 is the second-order gradient correction term, which is used to speed up the convergence; Item 4 is a random disturbance term, which is helpful to escape from the local optimal solution.

[0042] In general, step S50 realizes adaptive adjustment of detection parameters, makes full use of weld quality evaluation results to dynamically optimize various detection parameters, and improves the performance and accuracy of the entire detection system.

[0043] Finally, for step S60, real-time monitoring and early warning need to be performed. This includes: Construction of weld state vector: Constructing the weld state vector , including completeness indicators , stress concentration index and fatigue damage index These indicators reflect the overall quality of the weld and provide a basis for subsequent safety warnings.

[0044] Setting of safety threshold matrix: Setting the security threshold matrix ,Set a reasonable safety upper limit for each indicator. For example, Once any indicator exceeds the threshold, the early warning mechanism will be triggered.

[0045] Real-time monitoring and abnormal warning: The system will continuously collect and analyze various indicator data Once any indicator is found , an early warning signal will be issued immediately. This can timely detect abnormal weld quality, provide support for subsequent maintenance, and improve overall safety.

[0046] In general, step S60 establishes a real-time monitoring and early warning mechanism, which monitors key indicators such as weld integrity, stress concentration and fatigue damage in real time by setting reasonable safety thresholds. Once an abnormal situation is found, it can provide timely warnings to support subsequent maintenance and ensure the safe operation of the system.

[0047] A second aspect of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores program instructions, and when the program instructions are executed in a computer, they are used to execute the above-mentioned weld detection method for welding of a petroleum storage tank floating plate.

[0048] A third aspect of the present invention provides a weld detection system for welding of a petroleum storage tank floating plate, which includes the above-mentioned computer-readable storage medium.

[0049] Specifically, the principle of the present invention is to make full use of the motion characteristic data of the floating plate, realize accurate analysis of the dynamic stress and strain state of the weld through matrix operation, and carry out comprehensive quality evaluation and real-time monitoring and early warning based on this. The key to this method is to establish a close relationship between the motion characteristics of the floating plate and the mechanical behavior of the weld.

[0050] Firstly, the motion characteristic matrix of the floating plate was constructed, including the height matrix, attitude matrix and relative displacement matrix. Among them, the height matrix records the real-time height data of each measuring point at different times, reflecting the displacement change of the floating plate in the vertical direction; the attitude matrix contains the pitch angle, roll angle, yaw angle and the velocity components in three directions, describing the attitude change of the floating plate in the horizontal and vertical directions; the relative displacement matrix gives the deformation of the circumferential weld and radial weld during the floating process. These data lay the necessary foundation for the subsequent stress-strain analysis.

[0051] Secondly, three common non-destructive detection features were collected for welds, namely ultrasonic flaw detection, X-ray imaging and surface morphology. These test results were recorded in the form of a matrix, providing multi-angle data support for the comprehensive evaluation of weld quality.

[0052] On this basis, a set of stress-strain correlation equations was established, including equations for principal stress calculation, shear stress calculation, strain distribution, and fatigue damage accumulation. These equations fully consider the dynamic working conditions unique to floating plates, such as hydrostatic pressure, attitude angle changes, and movement speed, and accurately simulate the stress-strain state of the weld. Through matrix operations, the stress-strain distribution of each part of the weld can be quickly obtained, providing a theoretical basis for subsequent comprehensive evaluation.

[0053] In order to ensure the accuracy of the detection results, adaptive adjustment of detection parameters is also realized. Specifically, an optimization matrix containing key parameters such as ultrasonic angle, X-ray parameters and strain acquisition frequency is established. Using the weld quality evaluation results as the optimization target, the parameter update equation combining gradient descent and Newton method can dynamically find the best combination of detection parameters and continuously improve the performance of the entire detection system.

[0054] Finally, a weld status monitoring and early warning mechanism was constructed. Three indicators reflecting the overall quality of the weld were defined, namely the integrity indicator, stress concentration indicator and fatigue damage indicator, and corresponding safety thresholds were set. The system will collect and analyze these indicator data in real time, and once any indicator is found to exceed the threshold, an early warning signal will be issued immediately. This not only can timely detect abnormal weld quality, but also provides strong support for subsequent maintenance, thereby ensuring the safe operation of the entire tank system.

[0055] The following is an example of a specific application scenario of the present invention: a certain offshore oil company carries out floating tank operation business in a certain area of ​​the South China Sea. The tank system consists of a cylindrical floating ship board with a diameter of 50 meters and a height of 30 meters and a built-in 100,000 cubic meter oil storage tank. In order to ensure the safe operation of the tank system, the company decided to use the weld detection method proposed in the present invention to comprehensively evaluate and monitor the welds on the floating ship board in real time.

[0056] First, the enterprise organizes relevant technical personnel to measure and model the motion characteristics of the floating board according to step S10 of the present invention.

[0057] Specifically, the technicians set up 100 height measurement points on the surface of the floating board and recorded the height data of each measurement point in real time through the hydrophone. After 24 hours of continuous collection, a height matrix H with 100 rows and 100 columns was formed: ; Among them, each element It represents the height value of the i-th measuring point at the j-th moment, in meters. By analyzing this height matrix, we can understand the displacement change of the floating board in the vertical direction.

[0058] In addition, the company set up a sensor at three angles and three directions of the floating board to monitor the attitude angle and movement speed of the floating board in real time. After 24 hours of continuous collection, the attitude matrix A was formed: ; Each row of data represents the pitch angle of the floating board. , Roll Angle , yaw angle And the velocity components in the x, y, and z directions These data reflect the attitude changes and motion characteristics of the floating board in the horizontal and vertical directions.

[0059] In addition, the company also installed displacement sensors on the surface of the floating ship to monitor the relative displacement of the circumferential weld and the radial weld in real time. After 24 hours of continuous data collection, a relative displacement matrix D was formed: ; in, Meters represent the relative displacement of the circumferential weld. Meters represent the relative displacement of the radial weld.

[0060] Through the above measurements and modeling, the company mastered the movement characteristic data of the floating plate under complex sea conditions, laying the foundation for subsequent weld inspection.

[0061] Next, the enterprise collects basic detection features of the weld according to step S20 of the present invention.

[0062] First, the technicians used an ultrasonic flaw detector to scan and inspect the welds on the floating slab. By adjusting the angle and position of the probe, the technicians obtained a 100-row 100-column ultrasonic reflection coefficient matrix. : ; Among them, each element It represents the ultrasonic reflection coefficient at the i-th detection position and j-th detection angle. By analyzing these data, the defects and discontinuities inside the weld can be understood.

[0063] In addition, the company also uses X-ray imaging technology to conduct a comprehensive scan of the pontoon plate welds. After multiple scans with different exposure parameters, the technicians obtained an X-ray penetration matrix with 100 rows and 100 columns. : ; Among them, each element It represents the X-ray penetration rate at the i-th detection position and the j-th exposure parameter. By analyzing these data, we can understand the overall quality of the weld, including internal defects, pores, etc.

[0064] Finally, the company used a 3D scanner to collect the surface morphology of the floating plate weld. After data processing, the technicians obtained a 100-row 100-column weld profile and defect distribution matrix. : ; Among them, each element It represents the weld profile height at the i-th detection position and the defect depth at the j-th detection position. By analyzing these data, the appearance quality characteristics of the weld can be understood.

[0065] In summary, through actual measurement and data collection, the company constructed the motion characteristic matrix of the floating plate and the basic detection matrix of the weld, laying the foundation for subsequent stress-strain analysis and comprehensive evaluation.

[0066] Subsequently, the enterprise conducted an in-depth analysis of the dynamic stress-strain state of the floating ship plate weld according to step S30 of the present invention.

[0067] First, based on the height matrix H, posture matrix A and relative displacement matrix D obtained above, the company calculated the stress matrix of the weld: : ; Each element in the matrix It represents the principal stress of the ith weld position, in megapascals. By analyzing this stress matrix, we can clearly understand the stress state of the weld under complex sea conditions.

[0068] On this basis, the company also calculated the strain matrix of the weld according to the mechanical properties parameters of the material. : ; Each element in the matrix It represents the equivalent strain value of the ith weld position, dimensionless. By analyzing the strain matrix, we can understand the deformation of the weld under stress.

[0069] Next, the company used the stress-strain correlation equations to further analyze the dynamic mechanical behavior of the weld. For example, based on the principal stress calculation equation, the technicians obtained the magnitude and direction of the principal stress in each part of the weld; based on the shear stress calculation equation, the technicians determined the shear stress distribution borne by the weld; based on the strain distribution equation, the technicians calculated the normal strain and shear strain state of the weld area; based on the fatigue damage accumulation equation, the technicians evaluated the fatigue damage degree of the weld. These results provide a theoretical basis for subsequent comprehensive evaluation.

[0070] Based on the above analysis, the company has mastered the complete stress-strain state information of the floating plate weld under complex sea conditions, laying the foundation for subsequent quality evaluation.

[0071] Next, the enterprise constructed a comprehensive evaluation matrix for weld quality according to step S40 of the present invention.

[0072] First, the company will obtain the ultrasonic flaw detection matrix , X-ray imaging matrix and the stress-strain matrix The weighted combination is performed to form a comprehensive evaluation matrix for weld quality : ; Among them, the weights of each detection method are set to 0.4, 0.3 and 0.3 respectively to reflect their importance to the weld quality evaluation.

[0073] Through the comprehensive evaluation matrix Through the analysis, the company can fully understand the overall quality status of the pontoon plate weld, including internal defects, appearance quality, mechanical properties and other indicators. This provides a key basis for subsequent inspection parameter optimization and safety monitoring.

[0074] Next, the enterprise adaptively adjusts the detection parameters according to step S50 of the present invention.

[0075] First, the company established a detection parameter matrix including ultrasonic flaw detection angle, X-ray exposure parameters and strain acquisition frequency. : ; Among them, each row corresponds to a set of detection parameter settings.

[0076] Based on the comprehensive evaluation matrix of weld quality obtained above , the enterprise constructed the following parameter update equation: ; Using this equation, the company continuously optimized the detection parameters to ensure that all types of detection methods were in the best state, thereby obtaining more accurate and reliable weld quality evaluation results. After three rounds of iterations, the company finally determined the following optimal parameter combination: ; With this set of optimized detection parameter settings, enterprises can ensure the accuracy of evaluation results and lay the foundation for subsequent real-time monitoring and early warning.

[0077] Finally, the enterprise established a real-time monitoring and abnormal warning mechanism for the weld status in accordance with step S60 of the present invention.

[0078] First, the company defined three indicators that reflect the overall quality of the weld: Integrity indicators , used to evaluate the internal defects of welds; Stress concentration index , used to evaluate the extreme stress states to which the weld is subjected; Fatigue damage index , used to evaluate the fatigue damage degree of welds.

[0079] For these three indicators, the company set safety thresholds respectively: ; That is to say, when any indicator exceeds the above threshold, the early warning mechanism will be triggered.

[0080] The company collects and analyzes the above three indicators in real time to form a weld state vector Once discovered If there is any abnormality in the weld quality, the system will immediately send out an early warning signal to remind the staff to check and repair it in time. This not only can timely detect abnormal weld quality, but also provides strong support for subsequent maintenance, ensuring the safe operation of the entire tank system.

[0081] It should be noted that the variables involved in the present invention are explained as shown in Table 1 below: Table 1 Variable explanation table

[0082] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for detecting weld seams of oil tank pontoon plate welding, characterized in that: The following steps are involved: S10, constructing a floating board motion characteristic matrix, including: collecting a height matrix of the floating board, recording real-time height data of measuring points at different positions; establishing a floating board attitude matrix, including pitch angle, roll angle, yaw angle and velocity components in three directions; obtaining a relative displacement matrix of the circumferential weld and the radial weld during the floating process of the floating board; S20, collecting the basic detection matrix of the weld, including: establishing an ultrasonic flaw detection feature matrix to record the ultrasonic reflection coefficient at different positions and different detection angles; constructing an X-ray imaging feature matrix to obtain the X-ray penetration at different positions and different exposure parameters; forming a weld surface morphology feature matrix, including weld contour and surface defect distribution information; S30, perform dynamic stress-strain analysis: establish a stress matrix including normal stress and shear stress components; construct a strain matrix including normal strain and shear strain components; calculate the stress field distribution considering the floating effect through the stress-strain correlation equation group; S40. Construct a comprehensive evaluation matrix for weld quality: perform weighted combination of ultrasonic flaw detection feature matrix, X-ray imaging feature matrix and stress-strain matrix; establish a weight coefficient matrix to ensure a reasonable proportion of various indicators; and form an evaluation matrix that reflects the overall quality status of the weld; S50, realizing adaptive adjustment of detection parameters: establishing a detection parameter matrix including ultrasonic angle, X-ray parameters and strain acquisition parameters; constructing a parameter update equation based on the weld quality evaluation matrix; realizing dynamic optimization and update of detection parameters; S60. Perform real-time monitoring and early warning: construct a weld state vector, including integrity indicators, stress concentration indicators and fatigue damage indicators; set a safety threshold matrix and establish early warning trigger conditions; realize real-time monitoring of the weld state and abnormal early warning.

2. A method for detecting weld seams of oil tank pontoon plates according to claim 1, characterized in that: The stress-strain correlation equation group includes a principal stress calculation equation, a shear stress calculation equation, a strain distribution equation, and a fatigue damage accumulation equation; The principal stress calculation equation is used to calculate the magnitude and direction of the principal stress at each point of the weld. The input includes the weld position coordinates, the height data of the floating ship plate, the attitude angle data and the velocity component. The output is the magnitude and direction of the principal stress at each measuring point. The shear stress calculation equation is used to determine the shear stress distribution of the weld, the input includes principal stress data, weld relative displacement data and material shear modulus, and the output is the shear stress component of each point of the weld and the maximum shear stress position; The strain distribution equation is used to calculate the deformation state of the weld, the input includes principal stress data, shear stress data, material elastic modulus and Poisson's ratio, and the output is the normal strain and shear strain distribution of the weld area; The fatigue damage accumulation equation is used to evaluate the fatigue state of the weld, and the input includes the number of stress cycles, stress amplitude, average stress and material fatigue parameters, and the output is the fatigue damage degree of each point of the weld; The parameter update equation is used to optimize the detection parameter setting. The input includes the current detection parameters, weld quality evaluation indicators, detection accuracy requirements and equipment performance constraints. The output is the updated ultrasonic incident angle, X-ray exposure parameters and strain acquisition frequency.

3. A method for detecting weld seams of oil tank pontoon plate welding according to claim 2, characterized in that: The buoyancy plate motion characteristic matrix is ​​expressed as follows: ; In the formula, Indicates The measurement point is The altitude value at the moment, in meters, is the number of measurement points, is the number of sampling moments; The posture matrix is ​​expressed as follows: ; In the formula, is the pitch angle, and the range is ; is the roll angle, and the range is ; is the yaw angle, and the range is ; are the velocity components in three directions, in meters per second; The relative displacement matrix is ​​expressed as follows: ; In the formula, is the relative displacement vector of the circumferential weld, is the radial weld relative displacement vector.

4. A method for detecting weld seams of oil tank pontoon plate welding according to claim 3, characterized in that: The principal stress calculation equation is expressed as follows: ; In the formula, is the stress in the x direction, is the stress in the y direction, is the shear stress, is the oil density, is the acceleration due to gravity, is the liquid level height, is the attitude influence coefficient, is the dynamic viscosity, where represents the principal stress, and the subscripts 1 and 2 represent the two principal stress values. is the maximum principal stress, is the minimum principal stress.

5. A method for detecting weld seams of oil tank pontoon plate welding according to claim 4, characterized in that: The shear stress calculation equation is expressed as follows: ; In the formula, is the shear modulus, is the shear strain, is the viscosity coefficient, is the coefficient of the second-order derivative term.

6. A method for detecting weld seams of oil tank pontoon plate welding according to claim 5, characterized in that: The strain distribution equation is expressed as follows: ; In the formula, is the elastic modulus, is Poisson's ratio, is the Kronecker symbol, are the components of the stress tensor, , is a subscript indicating the stress direction, where represents the normal direction of the stress surface, and the subscript j represents the direction of the stress; represents the trace of the stress tensor.

7. A method for detecting weld seams of oil tank pontoon plate welding according to claim 6, characterized in that: The fatigue damage accumulation equation is expressed as follows: ; In the formula, is the actual number of cycles, is the fatigue life, is the injury index, is the correction factor, is the stress amplitude, is the fatigue limit, is the material constant.

8. A method for detecting weld seams of oil tank pontoon plate welding according to claim 7, characterized in that: The parameter update equation is expressed as follows: ; In the formula, is the current parameter vector, is the learning rate, is the performance indicator function, is the second-order derivative weight, is a random disturbance term.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores program instructions, and when the program instructions are executed in a computer, they are used to execute the weld detection method for welding of a petroleum storage tank pontoon plate according to any one of claims 1 to 8.

10. A weld detection system for welding of oil tank floating plates, characterized in that: A computer-readable storage medium comprising the computer-readable storage medium of claim 9.

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