A hot continuous rolling sheet initial state characterization and tailor-welded deformation regulation method

Abstract

The application provides a hot-rolled sheet initial state characterization and tailor-welding deformation regulation method, and relates to the field of data processing. In the method, the rolling initial stress and out-of-plane deflection of the hot-rolled Kai-ping sheet are obtained, the rolling stress distribution function and the out-of-plane deflection distribution function are constructed, and are input into the hot-elastic-plastic coupling finite element simulation algorithm to simulate the tailor-welding process under the set tailor-welding process parameters; then, the variable analysis method is used for disturbance analysis to determine whether the initial state satisfies the critical condition, if yes, it is determined that the tailor-welding deformation is controllable, and the accurate regulation of the out-of-plane deformation of the tailor-welding surface is realized. The technical scheme provided by the application is convenient for improving the welding precision.

Description

Technical Field

[0001] This application relates to the technical field of data processing, specifically to a method for characterizing the initial state of hot-rolled thin plates and controlling welding deformation. Background Technology

[0002] As ship hull structures move towards lightweight and low-cost designs, hot-rolled flattened thin plates are gradually replacing traditional cold-rolled thin plates in large-size welded structures due to their high production efficiency and low material cost.

[0003] However, the rolling and leveling processes of these thin plates introduce significant residual stress in the thickness direction and out-of-plane deflection disturbances in the length direction, becoming key factors inducing unstable buckling during the welding process, severely affecting construction accuracy and welding quality. Related technologies lack a systematic method for accurately characterizing the initial state of hot-rolled and leveled thin plates, and have not established a quantitative mapping relationship between it and welding deformation. Furthermore, there is no operable control mechanism to prevent unstable buckling, resulting in low welding accuracy.

[0004] Therefore, there is an urgent need for a method to characterize the initial state of hot-rolled thin plates and control welding deformation. Summary of the Invention

[0005] This application provides a method for characterizing the initial state of hot-rolled thin plates and controlling welding deformation, which facilitates the improvement of welding accuracy.

[0006] The first aspect of this application provides a method for characterizing the initial state of hot-rolled thin plates and controlling welding deformation. The method includes: obtaining the initial rolling stress on the front and back sides of a hot-rolled leveled thin plate, and constructing a rolling stress distribution function along the plate thickness direction based on the initial rolling stress on the front and back sides; obtaining the initial out-of-plane deflection at the starting end, the ending end, and the maximum out-of-plane deflection in the middle section of the hot-rolled leveled thin plate, and constructing an out-of-plane deflection distribution function along the plate length direction based on the out-of-plane deflection values ​​corresponding to the initial out-of-plane deflection at the starting end, the ending end, and the maximum out-of-plane deflection in the middle section; and combining the rolling stress distribution function with the out-of-plane deflection distribution function. The deflection distribution function is input into a finite element simulation algorithm that includes a thermo-elastic-plastic coupling mechanism. Based on the set welding process parameters, a finite element simulation of the hot-rolled flattened thin plate welding process is performed to obtain the external deformation results after welding. Based on the variable analysis method, the parameters in the rolling stress distribution function and the parameters in the out-of-plane deflection distribution function are subjected to perturbation analysis, and it is determined whether the initial state of the hot-rolled flattened thin plate meets the critical condition. If it is determined that the initial state corresponding to the rolling stress distribution function and the out-of-plane deflection distribution function meets the critical condition, then it is determined that the external deformation after welding is less than the preset deformation upper limit, so as to realize the control of the welding deformation of the hot-rolled flattened thin plate.

[0007] Optionally, obtaining the initial rolling stress on the front and back sides of the hot-rolled flattened sheet, and constructing a rolling stress distribution function along the sheet thickness direction based on the initial rolling stress on the front and back sides, specifically includes: setting the initial rolling stress on the front side as a first boundary condition, setting the initial rolling stress on the back side as a second boundary condition, and simultaneously setting the integral value of the rolling stress along the sheet thickness direction within the sheet thickness range to zero to satisfy the internal stress balance condition; based on the first boundary condition, the second boundary condition, and the internal stress balance condition, solving for the undetermined coefficients of the quadratic function representing the trend of the rolling stress along the sheet thickness direction to determine the rolling stress distribution function, which is used to describe the continuous rolling stress state of the hot-rolled flattened sheet along the thickness direction.

[0008] Optionally, obtaining the initial end out-of-plane deflection, the final end out-of-plane deflection, and the maximum out-of-plane deflection in the middle section of the hot-rolled and leveled thin plate, and constructing an out-of-plane deflection distribution function along the length of the plate based on the out-of-plane deflection values ​​corresponding to the initial end out-of-plane deflection, the final end out-of-plane deflection, and the maximum out-of-plane deflection in the middle section, specifically includes: using the initial end out-of-plane deflection as a third boundary condition, the final end out-of-plane deflection as a fourth boundary condition, and the maximum out-of-plane deflection in the middle section as a fifth boundary condition; setting the out-of-plane deflection distribution function to a quadratic function form that satisfies the third, fourth, and fifth boundary conditions, and solving for the function coefficients to determine the out-of-plane deflection distribution function, wherein the out-of-plane deflection distribution function is used to describe the continuous out-of-plane geometric deformation state of the hot-rolled and leveled thin plate along its length.

[0009] Optionally, the step of inputting the rolling stress distribution function and the out-of-plane deflection distribution function into a finite element simulation algorithm containing a thermo-elastic-plastic coupling mechanism, and performing a finite element simulation of the hot continuous rolling leveling and welding process of thin plates based on the set welding process parameters to obtain the out-of-plane deformation results after welding, specifically includes: in the finite element simulation algorithm containing a thermo-elastic-plastic coupling mechanism, using the rolling stress distribution function as the initial residual stress field input along the plate thickness direction, and using the out-of-plane deflection distribution function as the initial geometric perturbation field input along the plate length direction; obtaining the welding process parameters, The welding process parameters include the submerged arc welding single-sided welding double-sided forming welding process, welding current, welding voltage, and welding speed. During the finite element simulation, heat input and mechanical response are simultaneously applied. Based on the welding process parameters, the welding process simulation is performed using a thermo-elastic-plastic coupling algorithm, and the external deformation cloud map after welding is output. The maximum out-of-plane deformation value at the weld joint is extracted from the external deformation cloud map after welding. The maximum out-of-plane deformation value is used to evaluate the degree of welding deformation of the hot-rolled leveled thin plate. The external deformation result after welding includes the external deformation cloud map after welding and the maximum out-of-plane deformation value.

[0010] Optionally, the step of performing perturbation analysis on the parameters in the rolling stress distribution function and the parameters in the out-of-plane deflection distribution function based on the variable analysis method, and determining whether the initial state of the hot-rolled leveled thin plate meets the critical condition, specifically includes: selecting the function parameters in the rolling stress distribution function and the function parameters in the out-of-plane deflection distribution function as perturbation variables according to the variable analysis method, and constructing multiple perturbation combinations; inputting each perturbation combination into the finite element simulation algorithm to obtain the maximum out-of-plane deformation value; comparing the maximum out-of-plane deformation value with the preset deformation upper limit to determine whether the initial state corresponding to the perturbation combination causes welding instability; and constructing a critical boundary in the function parameter space that separates the welding stability zone and the welding instability zone based on the perturbation simulation results, as the basis for determining whether the initial state of the hot-rolled leveled thin plate meets the critical condition.

[0011] Optionally, if it is determined that the initial state corresponding to the rolling stress distribution function and the out-of-plane deflection distribution function satisfies the critical condition, then it is determined that the out-of-plane deformation after welding is less than the preset deformation upper limit, so as to achieve the control of the welding deformation of the hot-rolled leveled thin plate, specifically includes: if it is determined that the initial state corresponding to the rolling stress distribution function and the out-of-plane deflection distribution function satisfies the critical condition, then it is determined that the maximum out-of-plane deformation of the hot-rolled leveled thin plate after welding under the welding process parameters is less than the preset deformation upper limit, then there is no need to perform post-weld straightening processing.

[0012] Optionally, if it is determined that the initial state corresponding to the rolling stress distribution function and the out-of-plane deflection distribution function does not meet the critical condition, then it is determined that the maximum out-of-plane deformation of the hot-rolled leveled thin plate after welding under the welding process parameters is greater than the preset deformation upper limit, constituting welding instability behavior, and thereby identifying the risk of welding deformation exceeding the limit caused by the initial state, as a criterion for controlling the welding construction accuracy and implementing early state correction.

[0013] A second aspect of this application provides a device for characterizing the initial state of hot-rolled thin plates and controlling welding deformation. The device includes an acquisition module and a processing module. The acquisition module is used to acquire the initial rolling stress on the front and back sides of the hot-rolled leveled thin plate, and construct a rolling stress distribution function along the thickness direction of the plate based on the initial rolling stress on the front and back sides. The acquisition module is also used to acquire the initial out-of-plane deflection at the starting end, the ending end, and the maximum out-of-plane deflection in the middle section of the hot-rolled leveled thin plate, and construct an out-of-plane deflection distribution function along the length direction of the plate based on the out-of-plane deflection values ​​corresponding to the initial out-of-plane deflection at the starting end, the ending end, and the maximum out-of-plane deflection in the middle section. The processing module is used to process the rolling stress... The force distribution function and the out-of-plane deflection distribution function are input into a finite element simulation algorithm that includes a thermo-elastic-plastic coupling mechanism. Based on the set welding process parameters, a finite element simulation of the hot-rolled leveled thin plate welding process is performed to obtain the out-of-plane deformation results after welding. The processing module is also used to perform perturbation analysis on the parameters in the rolling stress distribution function and the parameters in the out-of-plane deflection distribution function based on the variable analysis method, and to determine whether the initial state of the hot-rolled leveled thin plate meets the critical condition. The processing module is also used to determine that if the initial state corresponding to the rolling stress distribution function and the out-of-plane deflection distribution function meets the critical condition, the out-of-plane deformation after welding is less than a preset deformation upper limit, so as to realize the control of the welding deformation of the hot-rolled leveled thin plate.

[0014] A third aspect of this application provides an electronic device including a processor, a memory, a user interface, and a network interface. The memory is used to store instructions, and both the user interface and the network interface are used to communicate with other devices. The processor is used to execute the instructions stored in the memory to cause the electronic device to perform the method described above.

[0015] A fourth aspect of this application provides a computer-readable storage medium storing instructions that, when executed, perform the method described above.

[0016] In summary, one or more technical solutions provided in this application have at least the following technical effects or advantages:

[0017] 1. By constructing the rolling stress distribution function and out-of-plane deflection distribution function of hot-rolled leveled thin plates, and inputting them into a thermo-elastic-plastic finite element simulation algorithm, and combining variable analysis to determine whether they meet the critical conditions, the out-of-plane deformation after welding can be predicted and controlled. This achieves full-process precision control from initial state modeling and response prediction to risk assessment, significantly improving the controllability of the welding process and the consistency of the weld morphology. Therefore, it facilitates the improvement of welding accuracy.

[0018] 2. Using variable analysis to analyze the initial state disturbance sensitivity and extract critical conditions, and establishing the boundaries between the stable and unstable welding regions in the function parameter space, is the theoretical basis for achieving the ability to predict welding accuracy. Inputting the rolling stress distribution function and the out-of-plane deflection distribution function into the thermo-elastic-plastic coupled finite element simulation, and combining it with the welding process parameters to perform full-process simulation, is the key transfer path from the initial state to the welding response. Attached Figure Description

[0019] Figure 1 A flowchart illustrating a method for characterizing the initial state of hot-rolled thin plates and controlling welding deformation, provided in an embodiment of this application;

[0020] Figure 2 A schematic diagram of a module for characterizing the initial state of hot-rolled thin plates and controlling welding deformation, provided in an embodiment of this application;

[0021] Figure 3 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application.

[0022] Explanation of reference numerals in the attached figures: 21. Acquisition module; 22. Processing module; 31. Processor; 32. Communication bus; 33. User interface; 34. Network interface; 35. Memory. Detailed Implementation

[0023] To enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0024] In the description of the embodiments of this application, the words "for example" or "for instance" are used to indicate examples, illustrations, or explanations. Any embodiment or design that is described as "for example" or "for instance" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design options. Rather, the use of the words "for example" or "for instance" is intended to present the relevant concepts in a specific manner.

[0025] In the description of the embodiments of this application, the term "multiple" means two or more. For example, multiple systems means two or more systems, and multiple screen terminals means two or more screen terminals. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. The terms "comprising," "including," "having," and variations thereof all mean "including but not limited to," unless otherwise specifically emphasized.

[0026] As the requirements for lightweighting and cost control in ship hull structures continue to increase, hot-rolled flattened sheets are increasingly replacing traditional cold-rolled sheets in the manufacture of large-size welded structures due to their advantages of high forming efficiency and low material cost.

[0027] However, during the rolling and leveling processes, these types of plates are prone to developing significant residual stresses along the thickness direction and out-of-plane deflection disturbances along the length direction. These initial state factors can easily trigger out-of-plane buckling instability during the welding process, directly affecting the stability of the weld morphology and the construction accuracy. Current technologies lack functional modeling methods that can accurately characterize the initial state of hot-rolled and leveled thin plates, and have not established a quantitative correlation mechanism between the initial state and the welding deformation response. Furthermore, there are no effective engineering means to controllably adjust the initial disturbances, resulting in insufficient stability assurance during the welding process and severely restricting the feasibility and reliability of precision welding processes.

[0028] To address the aforementioned technical problems, this application provides a method for characterizing the initial state of hot-rolled thin plates and controlling welding deformation, referring to... Figure 1 , Figure 1 This is a flowchart illustrating a method for characterizing the initial state of hot-rolled thin plates and controlling welding deformation, provided in an embodiment of this application. The method is applied to a server and includes steps S110 to S150, as follows:

[0029] S110. Obtain the initial rolling stress on the front and back sides of the hot-rolled flattened thin plate, and construct the rolling stress distribution function along the thickness direction of the plate based on the initial rolling stress on the front and back sides.

[0030] Specifically, in this application, the server does not refer to a traditional computer service node in network communication, but rather to a computing platform or simulation control unit that undertakes computational tasks such as initial data processing, function solving, and simulation analysis. It is mainly used to receive data input from the physical measurement end and execute stress function construction and subsequent welding simulation analysis. Hot-rolled flat sheet refers to steel plates produced through hot rolling and then flattened. It is characterized by its large size and is commonly used in large structural components such as ship hulls and bridges. The hot rolling process involves continuous rolling at high temperatures, followed by flattening through a combination of tension and bending. This process inevitably introduces asymmetric stress in the thickness direction and residual deformation in the length direction. In the embodiments of this application, the hot-rolled flat sheet used has dimensions of 600mm in length, 200mm in width, and 5mm in thickness, and is made of CCS B grade ship plate steel.

[0031] The initial rolling stress on the front and back sides refers to the initial residual stress values ​​retained on the upper and lower free surfaces of the hot-rolled flat sheet. These are measured results of the rolling stress at the thickness boundary points and have a decisive boundary effect. In this embodiment, the initial stress on the front side of the hot-rolled flat sheet was measured to be 176 MPa, and on the back side, it was 106 MPa, using X-ray diffraction (XRD). These two values ​​are directly used as boundary inputs for the rolling stress distribution function, reflecting the asymmetry of stress on the upper and lower surfaces of the sheet. The rolling stress distribution function is a continuous mathematical modeling expression of the rolling residual stress in the thickness direction of the sheet.

[0032] Therefore, starting from the measured initial rolling stress on both sides, a rolling stress distribution function with physical meaning is constructed, so that the residual stress state in the thickness direction of the hot-rolled flattened thin plate can be mathematically input into the simulation model of the welding process, thereby establishing a causal relationship between the initial disturbance and the welding instability response.

[0033] In one possible implementation, the initial rolling stress on the front and back sides of the hot-rolled flattened sheet is obtained, and a rolling stress distribution function along the thickness direction of the sheet is constructed based on the initial rolling stress on the front and back sides. Specifically, this includes: setting the initial rolling stress on the front side as a first boundary condition, setting the initial rolling stress on the back side as a second boundary condition, and setting the integral value of the rolling stress along the thickness direction of the sheet to zero within the thickness range of the sheet to satisfy the internal stress balance condition; based on the first boundary condition, the second boundary condition, and the internal stress balance condition, solving for the undetermined coefficients of the quadratic function representing the trend of rolling stress variation along the thickness direction of the sheet to determine the rolling stress distribution function, which is used to describe the continuous rolling stress state along the thickness direction of the hot-rolled flattened sheet.

[0034] Specifically, firstly, a hot-rolled, leveled thin plate sample was selected for testing. The sample dimensions were 600 mm in length, 200 mm in width, and 5 mm in thickness, made of CCSB grade ship plate steel. After hot rolling and leveling, the sample entered the stress measurement process. X-ray diffraction (XRD) was used to detect residual stress on the front and back sides of the sample. By selecting standard locations on the upper and lower surfaces for testing, the initial rolling stress on the front side of the hot-rolled, leveled thin plate was found to be 176 MPa, and the initial rolling stress on the back side was found to be 106 MPa. These were used as the first and second boundary conditions input in the modeling of this function, respectively.

[0035] Secondly, the coordinates in the thickness direction of the plate are set as follows: ,in Indicates the reverse side of the board. Indicates the front side of the board, thickness The value is taken as 5 mm. The rolling stress distribution function is defined as a quadratic function along the thickness direction:

[0036]

[0037] in: : Indicates the position in the thickness direction The rolling stress at the point is expressed in megapascals (MPa). : These are the function coefficients to be determined, reflecting the nonlinear variation trend of rolling stress; : Thickness direction coordinates, range of ; : Sheet thickness, in millimeters, here we take 5 millimeters.

[0038] Then, construct the three conditions required for the function to solve: ① Boundary stress constraint one: the reverse stress is 106 MPa, corresponding to:

[0039]

[0040] ② Boundary stress constraint two: The frontal stress is 176 MPa, corresponding to:

[0041]

[0042] ③ Internal stress equilibrium condition: The integral of rolling stress along the entire thickness direction is zero, that is:

[0043]

[0044] Substituting into the quadratic function expression, we can expand it to:

[0045]

[0046] Will Substituting millimeters into the three constraints above, we construct the equation regarding millimeters. The system of three linear equations in three variables is as follows:

[0047]

[0048] Solving this system of equations yields a uniquely determined solution. Values, for example, a=33.84, b=-155.2, c=106. This allows us to obtain the rolling stress distribution function of the hot-rolled, leveled thin plate. This function expression fully describes the continuous variation characteristics of rolling residual stress along the thickness direction, and possesses physical boundary consistency and overall internal stress balance.

[0049] Finally, the obtained rolling stress distribution function is used as the input parameter for the initial residual stress state in the thickness direction of the hot-rolled leveled thin plate, and loaded into the subsequent thermo-elastic-plastic coupled finite element simulation model. This model participates in the full-process modeling of the thermal deformation response during the welding process, serving as a key basis for predicting out-of-plane deformation and assessing welding stability. This step ensures high-fidelity transfer between measured data, function modeling, and engineering simulation, constituting the core link in the initial state modeling of the hot-rolled leveled thin plate.

[0050] S120. Obtain the out-of-plane deflection at the starting end, the out-of-plane deflection at the ending end, and the maximum out-of-plane deflection in the middle section of the hot-rolled flattened sheet. Based on the out-of-plane deflection values ​​corresponding to the starting end, the ending end, and the maximum out-of-plane deflection in the middle section, construct an out-of-plane deflection distribution function along the length of the sheet.

[0051] Specifically, the initial out-of-plane deflection refers to the deviation along the perpendicular direction of the plate at the starting end (usually x=0) in the length direction of the plate; the final out-of-plane deflection refers to the out-of-plane deviation at the end (usually x=l) in the length direction of the plate; the maximum out-of-plane deflection in the middle section refers to the extreme value of the out-of-plane deflection at the midpoint (usually x=l / 2) in the length direction of the plate, which is generally a negative deflection, i.e., a depression. In the embodiments of this application, the maximum out-of-plane deflection in the middle section of a certain hot-rolled leveled thin plate is obtained as -0.650mm through laser scanning and point cloud processing, and this value is the key input for function modeling. The out-of-plane deflection distribution function is a mathematical function used to describe the trend of out-of-plane deflection in the length direction of the hot-rolled leveled thin plate, and is constructed as a quadratic function with boundary interpolation capability.

[0052] Therefore, by obtaining three spatially representative out-of-plane deflection feature values, a function is constructed to express the geometric disturbance morphology along the length of the plate, realizing the transformation from discrete measurement data to continuous function modeling, and providing an accurate initial geometric input basis for the simulation of instability in hot continuous rolling thin plate welding.

[0053] In one possible implementation, the out-of-plane deflection at the starting end, the out-of-plane deflection at the ending end, and the maximum out-of-plane deflection in the middle section of the hot-rolled leveled thin plate are obtained. Based on the out-of-plane deflection values ​​corresponding to the starting end, the ending end, and the maximum out-of-plane deflection in the middle section, an out-of-plane deflection distribution function along the length of the plate is constructed. Specifically, this includes: using the starting end out-of-plane deflection as the third boundary condition, the ending end out-of-plane deflection as the fourth boundary condition, and the maximum out-of-plane deflection in the middle section as the fifth boundary condition; setting the out-of-plane deflection distribution function as a quadratic function satisfying the third, fourth, and fifth boundary conditions, and solving for the function coefficients to determine the out-of-plane deflection distribution function. The out-of-plane deflection distribution function is used to describe the continuous out-of-plane geometric deformation state of the hot-rolled leveled thin plate along its length.

[0054] Specifically, firstly, out-of-plane deflection measurements were performed on hot-rolled and leveled thin plates. The samples were CCSB-grade ship plate steel that had undergone hot rolling and leveling, with dimensions of 600 mm in length, 200 mm in width, and 5 mm in thickness. Out-of-plane deflection measurements were performed using a laser scanning device. Identification markers were pre-attached to the plate surface, and high-density point cloud data was acquired through laser scanning. Subsequently, point cloud spatial fitting and filtering were performed to reconstruct the out-of-plane deflection surface along the length of the plate, forming a deflection cloud map.

[0055] Secondly, from the reconstructed deflection cloud map, the out-of-plane deflection values ​​at three key locations are extracted: the starting end of the plate (i.e., Initial end face deflection at ) The middle section of the board (i.e. Maximum out-of-plane deflection at the mid-section of the point and the end of the board (i.e. Outer deflection of the termination end face at ) These three conditions serve as the third, fourth, and fifth boundary conditions required for function construction, respectively. Based on a measured example, the maximum out-of-plane deflection is -0.650 mm. If the out-of-plane deflections at the starting and ending ends are -0.150 mm and -0.180 mm, respectively, then the following three constraints are obtained:

[0056]

[0057] Next, the out-of-plane deflection distribution function is defined. It is in the form of a quadratic function along the length of the plate:

[0058]

[0059] in: : Indicates position along the length direction The out-of-plane deflection at the point, in millimeters; : Coordinates along the length of the board, with values ​​ranging from (in millimeters); : These are the coefficients of the undetermined function, corresponding to the nonlinear curvature term, linear slope term, and constant term of the function, respectively.

[0060] Subsequently, the three sets of boundary conditions are substituted into the function to construct a system of linear equations:

[0061]

[0062] That is, to simplify to:

[0063]

[0064] Solve the system of three linear equations to obtain the function coefficients. For example, p≈5.3889×10 -6 q≈-0.003283, r=-0.150. This yields a uniquely determined out-of-plane deflection distribution function. This function is used to characterize the out-of-plane geometric perturbation behavior along the length of hot-rolled flattened sheets, and has good continuity and physical interpretability.

[0065] Finally, the constructed out-of-plane deflection distribution function, along with the thickness-direction rolling stress distribution function, is used as part of the initial geometric perturbation state of the sheet metal and input into the thermo-elastic-plastic coupled finite element simulation model to simulate the out-of-plane deformation response and buckling behavior during the welding process. This forms the foundational input for subsequent welding instability prediction and deformation control. This step realizes a closed-loop process from measured data to function modeling and then to simulation input, which is a key link in achieving accurate construction simulation.

[0066] S130. Input the rolling stress distribution function and the out-of-plane deflection distribution function into the finite element simulation algorithm containing the thermo-elastic-plastic coupling mechanism, and perform the finite element simulation of the hot continuous rolling leveling thin plate welding process based on the set welding process parameters to obtain the out-of-plane deformation results after welding.

[0067] Specifically, the thermo-elastic-plastic coupling mechanism refers to the physical coupling process that simultaneously considers heat conduction, elastic deformation, and plastic yielding during the finite element method (FEM) solution. Welding is a typical thermomechanical coupling problem. The welding heat source induces a temperature gradient distribution, and temperature changes lead to differences in thermal expansion, material yielding, and residual deformation. This coupling model must be introduced to accurately simulate the stress-strain evolution and out-of-plane instability response during the welding process. The finite element simulation algorithm is based on the finite element discretization method to establish a mathematical model for numerically solving the physical response of the hot-rolled, leveled, thin-plate welding process. In this simulation process, after inputting the plate material properties (such as the elastic-plastic constitutive relation of CCS B-grade ship steel), geometric model, initial state function, and boundary conditions, the welding heat input process and structural response are simulated through time-step integration, and the stress field, displacement field, and out-of-plane deformation contour map of the plate as a result of the welding process are output.

[0068] Welding process parameters refer to the parameter variables that control the welding input during the actual welding process, including welding method, welding current, welding voltage, and welding speed. The process used in this application embodiment is as follows: Welding method: submerged arc welding, single-sided welding with double-sided forming; Current: 330~340A; Voltage: 33~35V; Speed: 10mm / s. These parameters collectively determine the heat input power density distribution and serve as the basis for heat source modeling and energy loading in the simulation. The out-of-plane deformation result after welding refers to the structural geometric response result output after completing the thermo-elastic-plastic simulation, typically including a two-dimensional contour plot and quantitative indicators (such as maximum out-of-plane deflection). For example, when the initial state does not meet the critical conditions, the maximum out-of-plane deformation reaches 20.6mm, resulting in severe instability; when the initial state meets the critical conditions, the maximum out-of-plane deformation is only 4.8mm, indicating stable and controllable welding. This result serves as an important basis for judging welding accuracy, evaluating welding stability, and designing correction strategies.

[0069] In one possible implementation, the rolling stress distribution function and the out-of-plane deflection distribution function are input into a finite element simulation algorithm that incorporates a thermo-elastic-plastic coupling mechanism. Based on the set welding process parameters, a finite element simulation of the hot continuous rolling and leveling thin plate welding process is performed to obtain the out-of-plane deformation results after welding. Specifically, in the finite element simulation algorithm that incorporates a thermo-elastic-plastic coupling mechanism, the rolling stress distribution function is used as the initial residual stress field input along the plate thickness direction, and the out-of-plane deflection distribution function is used as the initial geometric perturbation field input along the plate length direction; the welding results are obtained. The process parameters for the welding process include the submerged arc welding single-sided welding double-sided forming welding process, welding current, welding voltage, and welding speed. During the finite element simulation, thermal input and mechanical response are simultaneously applied. Based on the welding process parameters, the welding process simulation is performed through a thermo-elastic-plastic coupling algorithm, and the external deformation cloud map after welding is output. The maximum out-of-plane deformation value at the weld joint is extracted from the external deformation cloud map after welding. The maximum out-of-plane deformation value is used to evaluate the degree of welding deformation of hot-rolled flattened thin plates. The external deformation results after welding include the external deformation cloud map after welding and the maximum out-of-plane deformation value.

[0070] Specifically, firstly, the rolling stress distribution function is defined as a field within the full thickness range of the finite element model, constituting the residual stress distribution input. The out-of-plane deflection distribution function constitutes the initial geometric perturbation in the finite element model, used to induce subsequent thermally guided buckling behavior. Secondly, the welding process parameters used in the hot-rolled, leveled, thin-plate welding process are obtained and injected into the finite element simulation process as thermal input boundary conditions. The welding process parameters include: welding method: submerged arc welding, single-sided welding, double-sided forming; welding current: range of 330~340A; welding voltage: range of 33~35V; welding speed: 10mm / s. The thermal input model is fitted using a Gaussian distributed heat source or a double ellipsoidal heat source model, and combined with the plate's thermal conductivity, specific heat capacity, and material phase transformation characteristics to form the thermal input module.

[0071] Subsequently, a thermo-elastic-plastic coupled algorithm was executed during the finite element simulation to solve the entire welding process response, specifically including the temperature field, thermal stress field, evolution of the structural plastic zone, and out-of-plane deformation response. This process employed transient integration to solve the heat conduction and mechanical equilibrium equations, and controlled the heat source path, loading time, and speed according to process parameters, outputting the post-weld structural response at different time steps in the simulation. Finally, an out-of-plane deformation contour map was output from the simulation results, showing the morphological changes in the length and width directions after the hot-rolled flattened thin plates were welded. Based on this contour map, the maximum out-of-plane deflection value of the weld seam region was extracted and defined as:

[0072]

[0073] in: : This represents the maximum out-of-plane deflection value of the welded area after welding, in mm; : For the simulation mesh Out-of-plane displacement at a point. This maximum out-of-plane deflection value serves as an important criterion for evaluating the welding stability and structural accuracy of hot-rolled flattened thin plates. If its value is lower than the preset deformation limit, it is judged that the welding process is stable and controllable; otherwise, it indicates welding instability or the need for initial state correction.

[0074] In summary, this technical solution functionalizes the true initial stress and deflection state of hot-rolled leveled thin plates, imports it into a thermo-elastic-plastic coupled finite element framework, and performs high-fidelity simulation of the entire welding process using actual welding parameters. Finally, it outputs the external deformation response results after welding, achieving accurate prediction and risk identification of welding deformation. This process provides feasible and quantifiable numerical simulation support for solving the welding instability problem of hot-rolled leveled thin plates.

[0075] S140. Based on the variable analysis method, the parameters in the rolling stress distribution function and the parameters in the out-of-plane deflection distribution function are subjected to disturbance analysis, and it is determined whether the initial state of the hot-rolled flattened sheet meets the critical conditions.

[0076] Specifically, variable analysis is a parameter scanning technique based on sensitivity perturbation and response mapping, mainly used to identify key initial parameters and parameter tolerance limits affecting out-of-plane deformation in welded plates. In this application, this method is used to set multiple perturbation combinations before simulation to detect the influence of the rolling stress distribution function and the out-of-plane deflection distribution function on the out-of-plane deformation response after welding, thereby determining whether there is a risk of instability in the initial state of the thin plate. The parameters in the rolling stress distribution function are a, b, and c, and the parameters in the out-of-plane deflection distribution function are p, q, and r. Perturbation analysis involves perturbing and combining the above function parameters to form multiple initial state combinations, which are then input into the finite element simulation model. In the embodiments of this application, each perturbation combination will generate the corresponding maximum out-of-plane deformation response. The initial state refers to the combined "rolling initial stress state" and "out-of-plane initial deflection state" of a hot-rolled and leveled thin plate to be welded. Further, it is the unique initial function set determined by the function parameters (a, b, c, p, q, r), which is the basic unit for simulation and judgment.

[0077] In the embodiments of this application, "critical condition" refers to the criteria for determining the stable and unstable boundaries in the function parameter space constructed from the results of perturbation analysis. For example, when w max ≤6.0mm is the acceptable upper limit for welding deformation. All perturbation combinations that make the simulated deformation result less than or equal to this value constitute the "stable region", and its boundary is the "critical condition". Once the parameter combination corresponding to the initial state of a thin plate is within this stable region, it can be assumed that unstable buckling will not occur after welding; conversely, if the parameter combination falls into the unstable region, early intervention is required.

[0078] In one possible implementation, based on variable analysis, disturbance analysis is performed on the parameters in the rolling stress distribution function and the parameters in the out-of-plane deflection distribution function to determine whether the initial state of the hot-rolled flattened sheet meets the critical condition. Specifically, this includes: selecting the function parameters in the rolling stress distribution function and the function parameters in the out-of-plane deflection distribution function as disturbance variables according to variable analysis, and constructing multiple disturbance combinations; inputting each disturbance combination into the finite element simulation algorithm to obtain the maximum out-of-plane deformation value; comparing the maximum out-of-plane deformation value with a preset deformation upper limit to determine whether the initial state corresponding to the disturbance combination causes welding instability; and constructing a critical boundary in the function parameter space that separates the welding stability zone and the welding instability zone based on the disturbance simulation results, as the basis for determining whether the initial state of the hot-rolled flattened sheet meets the critical condition.

[0079] Specifically, the implementation of the above technical solution is based on the rolling stress state and out-of-plane deflection state of the "hot-rolled flattened thin plate". By constructing parameter perturbation combinations in the function space and combining them with thermo-elastic-plastic finite element simulation to perform out-of-plane response analysis, a "critical boundary" separating weld stability and instability is finally constructed to determine the weldability of the initial state. The specific implementation process consists of the following four steps: First, selecting perturbation variables. Based on the rolling stress distribution function and out-of-plane deflection distribution function of the hot-rolled flattened thin plate, key parameters are extracted from the function forms to form a variable set for perturbation analysis. The rolling stress distribution function is as follows:

[0080]

[0081] in, Indicates the position in the thickness direction of the sheet metal The initial rolling stress at the point, in MPa; , , These are the functional coefficients describing stress curvature, linear offset, and surface boundary stress. The out-of-plane deflection distribution function has the following form:

[0082]

[0083] in, Indicates the position along the length of the board. The initial out-of-plane deflection at the location, in mm; , , These are the function coefficients describing the initial geometric perturbation trend, offset, and initial deflection baseline. The perturbation range for each function coefficient is defined, such as... ,by Represent the calibration value and construct a multidimensional parameter combination.

[0084] Secondly, a finite element simulation of perturbation combinations is constructed. The parameters mentioned above are sampled using Latin hypercube sampling or full factorial arrangement according to the set perturbation amplitude, forming a set of perturbation combinations covering the function space. Each perturbation combination... Each represents a set of independent initial state functions for hot-rolled and leveled thin plates. Each set of functions is input as the "initial residual stress field" and "initial geometric disturbance field" into the thermo-elastic-plastic coupled finite element simulation model, respectively. While keeping the welding process parameters consistent, the simulation of the entire welding process is performed, and the corresponding maximum out-of-plane deflection value after welding is output.

[0085] Then, the simulation output is extracted and instability is determined. The maximum out-of-plane deflection value is calculated for each disturbance combination:

[0086]

[0087] in For the first The out-of-plane deflection distribution in the simulation results of a perturbation combination; if ,in If a preset welding instability deformation threshold is set, for example, 6.0 mm, then the perturbation combination is considered to induce welding instability behavior; otherwise, it is considered stable. The function parameter space can be divided into a "welding stable region" and a "welding unstable region" based on the discrimination results of all perturbation combinations.

[0088] Finally, critical boundaries are constructed based on the perturbation simulation results. Boundary functions separating stable and unstable regions are constructed in the function coefficient space using a support vector machine classifier, logistic regression fitting, or convex hull algorithm.

[0089]

[0090] The critical boundary is defined as all interfaces in the six-dimensional function coefficient space that satisfy the welding stability limit. Its criterion can be applied to the actual initial state function of any hot-rolled, leveled thin plate. If a certain thin plate... If the weld falls within the stable zone, it is assumed that the welding deformation is under control under the set process and can be directly welded; otherwise, it indicates that prior correction is required to avoid welding instability.

[0091] This scheme constructs a reliable instability discrimination boundary by using high-dimensional perturbation mapping and finite element response, filling the technical gap of lacking a quantitative mapping relationship between the initial state of hot-rolled flattened thin plates and the out-of-plane deformation of the welded surface, and significantly improving the controllability of the construction accuracy of large-size welded structures.

[0092] S150. If the initial state corresponding to the rolling stress distribution function and the out-of-plane deflection distribution function is determined to meet the critical condition, then the out-of-plane deformation after welding is determined to be less than the preset upper limit of deformation, so as to realize the control of the welding deformation of hot continuous rolling leveled thin plates.

[0093] Specifically, welding deformation control refers to strategies such as determining in advance whether the initial state of the thin plate meets critical conditions, thereby deciding whether to proceed with the welding process and whether pretreatment is required, to achieve controllable screening of welding stability at the source. If the initial state meets the critical conditions, welding can be directly arranged without implementing subsequent complex straightening processes; otherwise, straightening or parameter optimization should be performed. This scheme, through function analysis and critical boundary identification mechanisms, realizes the transformation of the thin plate welding state from "result response" to "process judgment," demonstrating high engineering feasibility in ensuring structural construction accuracy.

[0094] In one possible implementation, if it is determined that the initial state corresponding to the rolling stress distribution function and the out-of-plane deflection distribution function meets the critical condition, then it is determined that the out-of-plane deformation after welding is less than the preset deformation upper limit, so as to achieve the control of the welding deformation of hot-rolled leveled thin plates. Specifically, if it is determined that the initial state corresponding to the rolling stress distribution function and the out-of-plane deflection distribution function meets the critical condition, then it is determined that the maximum out-of-plane deformation of the hot-rolled leveled thin plate after welding under the welding process parameters is less than the preset deformation upper limit, then there is no need to perform post-weld straightening treatment.

[0095] Specifically, firstly, after calibrating the rolling stress distribution function and out-of-plane deflection distribution function of the hot-rolled flattened sheet, the six function coefficients corresponding to these two types of function forms are jointly defined as the initial state of the hot-rolled flattened sheet. Then, based on the critical boundary of the function parameter space constructed by the variable analysis method, it is determined whether the initial state meets the critical conditions. Furthermore, if the initial state falls within the welding stability zone defined by the critical boundary, it is considered that the rolling residual stress state and initial geometric disturbance state of the hot-rolled flattened sheet will not induce welding instability under the given welding process parameters.

[0096] Subsequently, using the initial state of the hot-rolled, leveled thin plate as input, a finite element simulation model with a thermo-elastic-plastic coupling mechanism is invoked. Under the pre-set welding process parameters, the thermal input process is applied, and stress-strain and heat conduction behaviors are coupled to complete the finite element simulation of the entire welding process. The out-of-plane deformation cloud map in the simulation output is extracted, and the maximum out-of-plane deflection value is identified from the weld area. Furthermore, the above-mentioned maximum out-of-plane deflection value is compared with the preset upper limit of deformation specified by the engineering allowable standard, for example, 6.0 mm. If the maximum welding deformation does not exceed the critical tolerance, the welding accuracy of the hot-rolled, leveled thin plate is deemed acceptable.

[0097] Finally, based on the above judgment results, the post-weld straightening process for the thin plate was eliminated during project execution, and the process proceeded directly to the subsequent structural integration process. This process achieves proactive control by moving the initial state function expression and stability judgment mechanism to before welding, avoiding rework, straightening, or scrapping operations caused by excessive deformation after welding in traditional processes, and significantly improving the continuity of the construction process and the efficiency of plate utilization.

[0098] In one possible implementation, if it is determined that the initial state corresponding to the rolling stress distribution function and the out-of-plane deflection distribution function does not meet the critical condition, then it is determined that the maximum out-of-plane deformation of the hot-rolled flattened sheet after welding under the welding process parameters is greater than the preset deformation upper limit, constituting welding instability behavior, and thereby identifying the risk of welding deformation exceeding the limit caused by the initial state, which serves as the criterion for controlling the welding construction accuracy and implementing early state correction.

[0099] Specifically, firstly, after identifying the rolling stress distribution function and out-of-plane deflection distribution function parameters of the hot-rolled flattened thin plate, the server inputs the function parameter set corresponding to the initial state into the constructed critical boundary judgment model, and performs stability judgment based on the welding stability zone and welding instability zone boundary function constructed in the previous stage based on variable analysis. If the function parameter set is located in the welding instability zone, it indicates that the initial state has the potential risk of out-of-plane deformation exceeding the limit under the current welding process parameters, and no longer meets the critical condition for welding stability.

[0100] Subsequently, the server invokes a finite element simulation algorithm matching the aforementioned initial state function, using the rolling stress distribution function as the initial residual stress field input and the out-of-plane deflection distribution function as the initial geometric disturbance field input. Simultaneously, predetermined welding process parameters are loaded, including welding current, welding voltage, welding speed, and submerged arc welding double-sided forming method, among other thermal input and mechanical response conditions, to execute a full-process simulation of the welding process. The out-of-plane deformation cloud map of the weld area is extracted from the finite element simulation output, thereby identifying the maximum out-of-plane deflection value after the hot-rolled flattened thin plate is welded. Then, this maximum out-of-plane deflection value is compared with an engineering tolerance threshold. If the result does not meet the conditions, the welding process is considered to constitute welding instability under the current initial state and process parameters, meaning the deformation exceeds the allowable construction error range, posing a significant risk of structural inaccuracy.

[0101] Finally, based on the simulation output and judgment results, the server traces back to the out-of-plane deformation exceeding limits caused by key function parameters in the initial state. It identifies which characteristic variables in the rolling residual stress or geometric disturbances drive the abnormal evolution of the welding deformation, and uses this as the core criterion input for controlling construction accuracy. This provides the engineering team with a decision-making basis for whether to perform pre-welding state correction or screening operations, ensuring that subsequent welding construction is controllable within the accuracy tolerance. This process, through a feedforward prediction and simulation verification linkage mechanism, provides a quantifiable state screening path and error suppression strategy for the precise welding of large-size structures.

[0102] In summary, the technical effects achieved by the technical solutions described in this application are as follows: First, by using X-ray diffraction to obtain the initial rolling stress on the front and back sides, and constructing a rolling stress distribution function that satisfies boundary stress constraints and internal stress balance conditions, physical modeling of the continuous change of residual stress in the thickness direction of the plate is realized, solving the problem that traditional empirical methods cannot accurately describe stress gradients. Second, by extracting the out-of-plane deflection at the starting end, the out-of-plane deflection at the ending end, and the maximum out-of-plane deflection in the middle section through laser scanning and point cloud reconstruction, and constructing an out-of-plane deflection distribution function with spatial fitting accuracy, continuous modeling of geometric perturbations in the length direction is realized, breaking through the traditional morphological description method based on discrete value judgment.

[0103] Furthermore, by loading the two initial state functions mentioned above as explicit input parameters into a finite element simulation algorithm that incorporates a thermo-elastic-plastic coupling mechanism, the coupling response relationship between welding thermal input and initial state is established. This significantly improves the accuracy and repeatability of weld deformation prediction and avoids the bias of neglecting the influence of the initial state on weld deformation in existing methods. Further, by using variable analysis to systematically perturb the function parameters and combining the simulation results to extract the critical boundary of the initial state, stability interval discrimination for hot continuous rolling and leveling thin plate weld processes is achieved. This provides a quantitative basis for pre-weld state screening, in-weld parameter correction, and post-weld accuracy evaluation, solving the problem of traditional processes relying on empirical judgment and lacking a stability prediction mechanism.

[0104] Ultimately, if the initial state meets the critical conditions, it can ensure that the maximum out-of-plane deformation after welding is less than the preset upper limit of deformation, thus suppressing welding instability. If the critical conditions are not met, the risk of deformation exceeding the limit can be predicted in advance, realizing active control and closed-loop process control of the welding process, which significantly improves the engineering applicability and welding reliability of hot continuous rolling and leveling thin plates.

[0105] In summary, the technical solution of this application effectively solves the problem of unstable construction accuracy caused by the complexity of the initial state during the welding of hot-rolled and leveled thin plates. It forms a systematic control path from physical state acquisition, mathematical model establishment to simulation decision feedback, and the technical effect is significantly better than the existing process system.

[0106] This application also provides a device for characterizing the initial state of hot-rolled thin plates and controlling welding deformation, referring to... Figure 2 , Figure 2 This is a schematic diagram of a module for characterizing the initial state of a hot-rolled thin plate and controlling welding deformation, provided in an embodiment of this application. The device is a server, comprising an acquisition module 21 and a processing module 22. The acquisition module 21 acquires the initial rolling stress on the front and back sides of the hot-rolled leveled thin plate, and constructs a rolling stress distribution function along the plate thickness direction based on these initial stresses. The processing module 22 acquires the out-of-plane deflection at the starting end, the ending end, and the maximum out-of-plane deflection in the middle section of the hot-rolled leveled thin plate, and constructs an out-of-plane deflection distribution function along the plate length direction based on the corresponding out-of-plane deflection values. Module 22 inputs the rolling stress distribution function and the out-of-plane deflection distribution function into a finite element simulation algorithm that includes a thermo-elastic-plastic coupling mechanism. Based on the set welding process parameters, it performs a finite element simulation of the hot-rolled flattened thin plate welding process to obtain the out-of-plane deformation results after welding. The processing module 22 performs perturbation analysis on the parameters in the rolling stress distribution function and the out-of-plane deflection distribution function based on the variable analysis method, and determines whether the initial state of the hot-rolled flattened thin plate meets the critical conditions. If the processing module 22 determines that the initial state corresponding to the rolling stress distribution function and the out-of-plane deflection distribution function meets the critical conditions, it determines that the out-of-plane deformation after welding is less than the preset deformation upper limit, so as to realize the control of the welding deformation of the hot-rolled flattened thin plate.

[0107] In one possible implementation, the acquisition module 21 acquires the initial rolling stress on the front and back sides of the hot-rolled flattened sheet, and constructs a rolling stress distribution function along the thickness direction of the sheet based on the initial rolling stress on the front and back sides. Specifically, the processing module 22 sets the initial rolling stress on the front side as the first boundary condition and the initial rolling stress on the back side as the second boundary condition, and sets the integral value of the rolling stress along the thickness direction of the sheet to zero within the thickness range of the sheet to satisfy the internal stress balance condition. Based on the first boundary condition, the second boundary condition, and the internal stress balance condition, the processing module 22 solves for the undetermined coefficients of the quadratic function representing the trend of rolling stress along the thickness direction of the sheet to determine the rolling stress distribution function. The rolling stress distribution function is used to describe the continuous rolling stress state along the thickness direction of the hot-rolled flattened sheet.

[0108] In one possible implementation, the acquisition module 21 acquires the initial end out-of-plane deflection, the final end out-of-plane deflection, and the maximum out-of-plane deflection in the middle section of the hot-rolled flattened sheet. Based on the out-of-plane deflection values ​​corresponding to the initial end out-of-plane deflection, the final end out-of-plane deflection, and the maximum out-of-plane deflection in the middle section, it constructs an out-of-plane deflection distribution function along the length direction of the sheet. Specifically, the processing module 22 uses the initial end out-of-plane deflection as the third boundary condition, the final end out-of-plane deflection as the fourth boundary condition, and the maximum out-of-plane deflection in the middle section as the fifth boundary condition. The processing module 22 sets the out-of-plane deflection distribution function to a quadratic function form that satisfies the third, fourth, and fifth boundary conditions, and solves for the function coefficients to determine the out-of-plane deflection distribution function. The out-of-plane deflection distribution function is used to describe the continuous out-of-plane geometric deformation state of the hot-rolled flattened sheet along the length direction.

[0109] In one possible implementation, the processing module 22 inputs the rolling stress distribution function and the out-of-plane deflection distribution function into a finite element simulation algorithm that includes a thermo-elastic-plastic coupling mechanism, and performs a finite element simulation of the hot continuous rolling and leveling thin plate welding process based on the set welding process parameters to obtain the out-of-plane deformation results after welding. Specifically, the processing module 22 uses the rolling stress distribution function as the initial residual stress field input along the plate thickness direction and the out-of-plane deflection distribution function as the initial geometric disturbance field input along the plate length direction in the finite element simulation algorithm that includes a thermo-elastic-plastic coupling mechanism; the acquisition module 21 obtains... The welding process parameters are obtained, including the welding process method of submerged arc welding with single-sided welding and double-sided forming, welding current, welding voltage, and welding speed. During the finite element simulation, the processing module 22 synchronously loads the thermal input and mechanical response. Based on the welding process parameters, it performs the welding process simulation through a thermo-elastic-plastic coupling algorithm and outputs the external deformation cloud map after welding. The processing module 22 extracts the maximum out-of-plane deformation value at the weld seam from the external deformation cloud map after welding. The maximum out-of-plane deformation value is used to evaluate the degree of welding deformation of hot-rolled flattened thin plates. The external deformation result after welding includes the external deformation cloud map after welding and the maximum out-of-plane deformation value.

[0110] In one possible implementation, the processing module 22 performs perturbation analysis on the parameters in the rolling stress distribution function and the parameters in the out-of-plane deflection distribution function based on the variable analysis method, and determines whether the initial state of the hot-rolled flattened sheet meets the critical conditions. Specifically, the processing module 22 selects the function parameters in the rolling stress distribution function and the function parameters in the out-of-plane deflection distribution function as perturbation variables according to the variable analysis method, and constructs multiple perturbation combinations; the processing module 22 inputs each perturbation combination into the finite element simulation algorithm to obtain the maximum out-of-plane deformation value; the processing module 22 compares the maximum out-of-plane deformation value with the preset deformation upper limit to determine whether the initial state corresponding to the perturbation combination causes welding instability; the processing module 22 constructs the critical boundary separating the welding stability zone and the welding instability zone in the function parameter space based on the perturbation simulation results, as the basis for determining whether the initial state of the hot-rolled flattened sheet meets the critical conditions.

[0111] In one possible implementation, if the processing module 22 determines that the initial state corresponding to the rolling stress distribution function and the out-of-plane deflection distribution function meets the critical condition, then it determines that the out-of-plane deformation after welding is less than the preset deformation upper limit, so as to achieve the control of the welding deformation of the hot-rolled leveled thin plate. Specifically, if the processing module 22 determines that the initial state corresponding to the rolling stress distribution function and the out-of-plane deflection distribution function meets the critical condition, then it determines that the maximum out-of-plane deformation of the hot-rolled leveled thin plate after welding under the welding process parameters is less than the preset deformation upper limit, then there is no need to perform post-weld straightening processing.

[0112] In one possible implementation, if the processing module 22 determines that the initial state corresponding to the rolling stress distribution function and the out-of-plane deflection distribution function does not meet the critical conditions, it determines that the maximum out-of-plane deformation of the hot-rolled flattened sheet after welding under the welding process parameters is greater than the preset deformation limit, constituting welding instability behavior, and identifies the risk of welding deformation exceeding the limit caused by the initial state, as a criterion for controlling the welding construction accuracy and implementing early state correction.

[0113] It should be noted that the above embodiments of the apparatus are only illustrated by the division of the above functional modules. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. In addition, the apparatus and method embodiments provided in the above embodiments belong to the same concept, and the specific implementation process can be found in the method embodiments, which will not be repeated here.

[0114] This application also provides an electronic device, with reference to... Figure 3 , Figure 3This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. The electronic device may include: at least one processor 31, at least one network interface 34, a user interface 33, a memory 35, and at least one communication bus 32.

[0115] The communication bus 32 is used to enable communication between these components.

[0116] The user interface 33 may include a display screen and a camera. Optionally, the user interface 33 may also include a standard wired interface and a wireless interface.

[0117] The network interface 34 may optionally include a standard wired interface or a wireless interface (such as a Wi-Fi interface).

[0118] The processor 31 may include one or more processing cores. The processor 31 connects to various parts of the server via various interfaces and lines, executing instructions, programs, code sets, or instruction sets stored in the memory 35, and calling data stored in the memory 35 to perform various server functions and process data. Optionally, the processor 31 may be implemented using at least one hardware form of Digital Signal Processing (DSP), Field-Programmable Gate Array (FPGA), or Programmable Logic Array (PLA). The processor 31 may integrate one or a combination of several of the following: Central Processing Unit (CPU), Graphics Processing Unit (GPU), and modem. The CPU primarily handles the operating system, user interface, and applications; the GPU is responsible for rendering and drawing the content to be displayed on the screen; and the modem handles wireless communication. It is understood that the modem may also not be integrated into the processor 31 and may be implemented as a separate chip.

[0119] The memory 35 may include random access memory (RAM) or read-only memory. Optionally, the memory 35 may include a non-transitory computer-readable storage medium. The memory 35 can be used to store instructions, programs, code, code sets, or instruction sets. The memory 35 may include a program storage area and a data storage area, wherein the program storage area may store instructions for implementing an operating system, instructions for at least one function (such as touch function, sound playback function, image playback function, etc.), instructions for implementing the above-described method embodiments, etc.; the data storage area may store data involved in the above-described method embodiments, etc. Optionally, the memory 35 may also be at least one storage device located remotely from the aforementioned processor 31. Figure 3 As shown, the memory 35, which serves as a computer storage medium, may include an operating system, a network communication module, a user interface module, and an application program for characterizing the initial state of hot-rolled thin plates and controlling welding deformation.

[0120] exist Figure 3 In the electronic device shown, the user interface 33 is mainly used to provide an input interface for the user and to obtain the user input data; while the processor 31 can be used to call the application program stored in the memory 35, which is a method for characterizing the initial state of hot-rolled thin plates and controlling welding deformation. When executed by one or more processors, the electronic device executes one or more methods as described in the above embodiments.

[0121] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0122] This application also provides a computer-readable storage medium storing instructions. When executed by one or more processors, these instructions cause an electronic device to perform one or more of the methods described in the above embodiments.

[0123] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0124] In the several embodiments provided in this application, it should be understood that the disclosed apparatus can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the shown or discussed mutual couplings or direct couplings or communication connections may be through some service interfaces; indirect couplings or communication connections between apparatuses or units may be electrical or other forms.

[0125] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment, depending on actual needs.

[0126] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0127] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage device (CMD). Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a memory and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned memory includes various media capable of storing program code, such as USB flash drives, portable hard drives, magnetic disks, or optical disks.

[0128] The foregoing description is merely an exemplary embodiment of this disclosure and should not be construed as limiting the scope of this disclosure. Any equivalent changes and modifications made in accordance with the teachings of this disclosure shall still fall within the scope of this disclosure. Those skilled in the art will readily conceive of other embodiments of this disclosure upon considering the specification and the disclosure of practical truth. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not described in this disclosure. The specification and embodiments are considered exemplary only, and the scope and spirit of this disclosure are defined by the claims.

Claims

1. A method for characterizing the initial state of hot-rolled thin plates and controlling welding deformation, characterized in that, The method includes: The initial rolling stress on the front and back sides of the hot-rolled flattened sheet is obtained, and a rolling stress distribution function along the thickness direction of the sheet is constructed based on the initial rolling stress on the front and back sides. The out-of-plane deflection at the starting end, the out-of-plane deflection at the ending end, and the maximum out-of-plane deflection in the middle section of the hot-rolled and leveled thin plate are obtained. Based on the out-of-plane deflection values ​​corresponding to the starting end, the ending end, and the maximum out-of-plane deflection in the middle section, an out-of-plane deflection distribution function along the length of the plate is constructed. The rolling stress distribution function and the out-of-plane deflection distribution function are input into a finite element simulation algorithm that includes a thermo-elastic-plastic coupling mechanism. Based on the set welding process parameters, the finite element simulation of the hot continuous rolling leveling thin plate welding process is performed to obtain the out-of-plane deformation results after welding. Based on the variable analysis method, the parameters in the rolling stress distribution function and the parameters in the out-of-plane deflection distribution function are subjected to disturbance analysis, and it is determined whether the initial state of the hot-rolled flattened sheet meets the critical conditions. If the initial state corresponding to the rolling stress distribution function and the out-of-plane deflection distribution function is determined to meet the critical condition, then the out-of-plane deformation after welding is determined to be less than the preset upper limit of deformation, so as to achieve the control of the welding deformation of the hot continuous rolling leveled thin plate. The process of obtaining the initial rolling stress on the front and back sides of a hot-rolled, leveled thin plate, and constructing a rolling stress distribution function along the plate thickness direction based on the initial rolling stress on the front and back sides, specifically includes: The initial rolling stress on the front side is set as the first boundary condition, and the initial rolling stress on the back side is set as the second boundary condition. At the same time, the integral value of the rolling stress along the thickness direction of the plate is set to zero within the thickness range of the plate to satisfy the internal stress balance condition. Based on the first boundary condition, the second boundary condition, and the internal stress balance condition, the undetermined coefficients of the quadratic function representing the trend of the rolling stress along the thickness direction of the plate are solved to determine the rolling stress distribution function, which is used to describe the continuous rolling stress state of the hot-rolled flattened thin plate along the thickness direction. The process of obtaining the initial end-face out-of-plane deflection, the final end-face out-of-plane deflection, and the maximum out-of-plane deflection in the middle section of the hot-rolled and leveled thin plate, and constructing an out-of-plane deflection distribution function along the length of the plate based on the out-of-plane deflection values ​​corresponding to the initial end-face out-of-plane deflection, the final end-face out-of-plane deflection, and the maximum out-of-plane deflection in the middle section, specifically includes: The initial end-face out-of-plane deflection is used as the third boundary condition, the final end-face out-of-plane deflection is used as the fourth boundary condition, and the maximum out-of-plane deflection in the middle section is used as the fifth boundary condition. The out-of-plane deflection distribution function is defined as a quadratic function that satisfies the third boundary condition, the fourth boundary condition, and the fifth boundary condition, and the function coefficients are solved to determine the out-of-plane deflection distribution function. The out-of-plane deflection distribution function is used to describe the continuous out-of-plane geometric deformation state of the hot-rolled flattened sheet along the length direction.

2. The method for characterizing the initial state of hot-rolled thin plates and controlling welding deformation according to claim 1, characterized in that, The rolling stress distribution function and the out-of-plane deflection distribution function are input into a finite element simulation algorithm that includes a thermo-elastic-plastic coupling mechanism. Based on the set welding process parameters, a finite element simulation of the hot continuous rolling leveling thin plate welding process is performed to obtain the out-of-plane deformation results after welding. Specifically, this includes: In the finite element simulation algorithm that includes a thermo-elastic-plastic coupling mechanism, the rolling stress distribution function is used as the initial residual stress field input along the thickness direction of the plate, and the out-of-plane deflection distribution function is used as the initial geometric disturbance field input along the length direction of the plate. Obtain the welding process parameters, which include the submerged arc welding single-sided welding double-sided forming welding process, welding current, welding voltage, and welding speed; During the finite element simulation, thermal input and mechanical response are simultaneously applied. Based on the welding process parameters, the welding process simulation is performed using a thermo-elastic-plastic coupling algorithm, and the external deformation cloud map after welding is output. The maximum out-of-plane deformation value at the weld joint is extracted from the out-of-plane deformation cloud map after welding. The maximum out-of-plane deformation value is used to evaluate the degree of welding deformation of the hot-rolled leveled thin plate. The out-of-plane deformation result after welding includes the out-of-plane deformation cloud map after welding and the maximum out-of-plane deformation value.

3. The method for characterizing the initial state of hot-rolled thin plates and controlling welding deformation according to claim 2, characterized in that, The variable analysis method is used to perform perturbation analysis on the parameters in the rolling stress distribution function and the parameters in the out-of-plane deflection distribution function, and to determine whether the initial state of the hot-rolled leveled thin plate meets the critical conditions. Specifically, this includes: Based on the variable analysis method, the function parameters in the rolling stress distribution function and the function parameters in the out-of-plane deflection distribution function are selected as perturbation variables to construct multiple perturbation combinations; Each of the aforementioned perturbation combinations is input into the finite element simulation algorithm to obtain the maximum out-of-plane deformation value; The maximum out-of-plane deformation value is compared with the preset deformation limit to determine whether the initial state corresponding to the disturbance combination causes welding instability. Based on the disturbance simulation results, a critical boundary is constructed in the function parameter space to separate the welding stable zone and the welding unstable zone, which serves as the basis for determining whether the initial state of the hot-rolled flattened sheet meets the critical condition.

4. The method for characterizing the initial state of hot-rolled thin plates and controlling welding deformation according to claim 1, characterized in that, If the initial state corresponding to the rolling stress distribution function and the out-of-plane deflection distribution function satisfies the critical condition, then the out-of-plane deformation after welding is determined to be less than the preset deformation upper limit, so as to achieve the control of the welding deformation of the hot-rolled leveled thin plate, specifically including: If the initial state corresponding to the rolling stress distribution function and the out-of-plane deflection distribution function satisfies the critical condition, then the maximum out-of-plane deformation of the hot-rolled leveled thin plate after welding under the welding process parameters is less than the preset deformation upper limit, and no post-weld straightening treatment is required.

5. The method for characterizing the initial state of hot-rolled thin plates and controlling welding deformation according to claim 1, characterized in that, The method further includes: If it is determined that the initial state corresponding to the rolling stress distribution function and the out-of-plane deflection distribution function does not meet the critical condition, then it is determined that the maximum out-of-plane deformation of the hot-rolled leveled thin plate after welding under the welding process parameters is greater than the preset deformation upper limit, constituting welding instability behavior, and the risk of welding deformation exceeding the limit caused by the initial state is identified accordingly, which serves as the basis for controlling the welding construction accuracy and implementing early state correction.

6. A device for characterizing the initial state of hot-rolled thin plates and controlling welding deformation, characterized in that, The device is used to perform the initial state characterization and welding deformation control method for hot-rolled thin plates as described in any one of claims 1 to 5. The device includes an acquisition module (21) and a processing module (22), wherein, The acquisition module (21) is used to acquire the initial rolling stress on the front side and the initial rolling stress on the back side of the hot continuous rolling flattened sheet, and to construct a rolling stress distribution function along the thickness direction of the sheet based on the initial rolling stress on the front side and the initial rolling stress on the back side. The acquisition module (21) is also used to acquire the initial end face deflection, the final end face deflection and the maximum out-of-plane deflection in the middle section of the hot-rolled flattened sheet, and to construct an out-of-plane deflection distribution function along the length of the sheet based on the out-of-plane deflection values ​​corresponding to the initial end face deflection, the final end face deflection and the maximum out-of-plane deflection in the middle section. The processing module (22) is used to input the rolling stress distribution function and the out-of-plane deflection distribution function into a finite element simulation algorithm containing a thermo-elastic-plastic coupling mechanism, and perform a finite element simulation of the hot continuous rolling leveling thin plate welding process based on the set welding process parameters to obtain the out-of-plane deformation results after welding. The processing module (22) is also used to perform disturbance analysis on the parameters in the rolling stress distribution function and the parameters in the out-of-plane deflection distribution function based on the variable analysis method, and to determine whether the initial state of the hot-rolled flattened thin plate meets the critical conditions. The processing module (22) is further configured to determine that the external deformation after welding is less than the preset upper limit of deformation if the initial state corresponding to the rolling stress distribution function and the out-of-plane deflection distribution function satisfies the critical condition, so as to realize the control of the welding deformation of the hot continuous rolling leveling thin plate.

7. An electronic device, characterized in that, The electronic device includes a processor (31), a memory (35), a user interface (33), and a network interface (34). The memory (35) is used to store instructions. The user interface (33) and the network interface (34) are both used to communicate with other devices. The processor (31) is used to execute the instructions stored in the memory (35) to cause the electronic device to perform the method as described in any one of claims 1 to 5.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores instructions that, when executed, perform the method as described in any one of claims 1 to 5.

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