Finite element model modeling method for integral panel shot peening forming analysis

Abstract

The invention relates to the technical field of shot peening forming, in particular to a finite element model modeling method for integral panel shot peening forming analysis, which comprises the following steps of: establishing a panel shell geometric model consistent with a solid in thickness; determining a shot blasting area and conditions thereof; an equivalent load is determined based on shot blasting conditions, wherein a single-face shot blasting area is an equivalent linear density bending moment, and a double-face shot blasting area is an equivalent linear density bending moment and an equivalent thermal load; the equivalent load and constraints are applied to the model to complete modeling. According to the method, the elastic-plastic impact process of shot blasting is equivalent to the statics load acting on the shell, and the quantitative relation between the load and the process parameters is established by using the standard test, so that the calculation scale and the time cost of large-scale integral panel shot blasting forming simulation are greatly reduced on the premise of ensuring the prediction precision, and the method is suitable for large-scale integral panel shot blasting forming simulation. And an efficient and reliable analysis tool is provided for process design and optimization.

Description

Technical Field

[0001] This invention relates to the field of shot peening forming technology, and more specifically to a finite element modeling method for shot peening forming analysis of integral wall panels. Background Technology

[0002] Shot peening is currently the main forming method for large, lightweight alloy aircraft integral panels, offering advantages such as low cost, good process flexibility, and strong fatigue resistance in the formed parts. Its basic principle involves using a large number of rigid spherical projectiles to impact the surface of a specimen at high speed. The residual compressive stress field formed by the elasto-plastic impact of the projectiles causes macroscopic plastic deformation in the peened specimen. The shot peening of integral panels is a complex elasto-plastic dynamic process involving material nonlinearity, contact nonlinearity, and geometric nonlinearity, and is influenced by a combination of factors such as projectile velocity, projectile distribution, panel structure, and material mechanical properties. For a long time, achieving high-precision and high-efficiency numerical simulation of the shot peening process of large integral panels has been a challenging problem in this field.

[0003] The main challenge in finite element simulation of shot peening forming of large monolithic wall panels lies in the extremely small size and vast number of projectiles. Typical projectile diameters are usually within 3.18 mm, and at a projectile flow rate of 10 kg / min, the number of projectiles sprayed per minute can reach approximately 7.6 × 10⁻⁶. 4 Individually, integral wall panels, as a typical large-size thin-walled structure, typically have a thickness between 3mm and 20mm and a width of up to 2×10. 3 mm, while the length is usually 1×10 mm. 4 mm to 2×10 4 On the order of millimeters. If a direct simulation method is used to perform explicit dynamic elastoplastic analysis on the impact process of each projectile and finally calculate the deformation of the entire wall panel, it will generate a massive number of element and contact calculations, resulting in an exponential increase in the calculation scale and extremely high calculation costs, making it difficult to meet the timeliness requirements of engineering design and process optimization.

[0004] To overcome the above difficulties, researchers have proposed various approximate or equivalent simulation methods from different perspectives, but existing methods still have significant limitations in terms of computational efficiency and parameter correlation. For example, Grassy et al. proposed a finite element method based on the extrusion layer model in the paper "Shotpeen forming of sheet metal: finite element prediction of deformed shape[J]" (Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture, 1996, 210(B4): 361-366), which simplifies the shot peening effect to an equivalent pressure loading on the surface element, but does not establish a quantitative relationship between pressure and shot peening process parameters. Kang Xiaoming simulated narrow strip shot peening using the equivalent deformation method in the paper "Numerical simulation of narrow strip shot peening forming[J]" (Acta Aeronautica Sinica, 2002, 23(1):94-96), and established the correlation between equivalent deformation force and process parameters through experiments, but did not clarify the method for determining the equivalent load. Wang et al. proposed a method based on an equivalent temperature field in their paper "A process model for shot peenforming[J]" (Journal of Materials Processing Technology, 2006, 172: 159-162), using thermal load to simulate the deformation effect of shot peening. However, the setting of the temperature field depends on experience and its physical meaning is not clear enough. In addition, Chinese patent CN104866652A discloses a finite element simulation method for shot peening strengthening deformation based on ABAQUS. This method obtains the residual stress field through shot impact simulation and then uses it as the initial condition for static analysis. However, it fails to directly establish the analytical or semi-analytical relationship between shot peening parameters and the final equivalent load, thus limiting its universality and predictability. Chinese patent CN117951967A discloses a simulation method for shot peening forming based on a solid finite element model. This method attempts to couple a large number of shot models with solid workpieces for explicit-implicit joint solution. Although the accuracy may be high, the computational burden is still heavy and it is not suitable for rapid analysis and iterative design of shot peening forming processes for large integral panels.

[0005] Therefore, existing technologies in this field cannot simultaneously meet the dual requirements of computational efficiency and prediction accuracy for the simulation of shot peening forming of large integral wall panels. There is an urgent need to develop an efficient finite element modeling method that can accurately quantify the shot peening forming effect and significantly reduce computational costs, and is suitable for shot peening forming of large integral wall panels. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a finite element modeling method for shot peening forming analysis of integral wall panels. This method equates the shot peening deformation to a linear bending moment or thermal load acting on the shell model and establishes a quantitative relationship between this load and shot peening parameters and material thickness, thereby achieving efficient simulation of shot peening forming of large integral wall panels while ensuring accuracy.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] This invention proposes a finite element modeling method for shot peening forming analysis of integral wall panels, comprising the following steps:

[0009] S1. Establish the shell geometric model of the integral wall panel, wherein the thickness of the shell geometric model is consistent with the thickness of the corresponding position of the integral wall panel;

[0010] S2. Based on the shot peening forming process, determine the area on the integral wall panel that needs to be shot peened and its corresponding shot peening conditions. The shot peening conditions include at least the shot peening surface, shot peening parameters, and whether prestress exists.

[0011] S3. Based on the shot peening conditions, determine the equivalent load for the corresponding area. The equivalent load includes at least one of equivalent linear density bending moment and equivalent thermal load. The equivalent linear density bending moment is used to simulate the bending deformation of the integral wall panel during the shot peening process, and the equivalent thermal load is used to simulate the elongation deformation of the integral wall panel during the shot peening process.

[0012] S4. Apply the equivalent load to the boundary or element of the corresponding region of the shell geometry model and apply constraints to establish a finite element model of the overall wall panel shot peening forming.

[0013] Furthermore, in S1, the shell geometric model is composed of the outer surface of the integral wall panel slab and the geometric mid-surface of the reinforcing ribs, and the deformation coordination constraints are satisfied at the connection between the segments.

[0014] Furthermore, in S2, the shot-peened surface includes a single-sided shot-peened surface or a double-sided shot-peened surface.

[0015] Furthermore, in S3, for regions where the shot-peened surface is a single-sided shot-peened surface, the equivalent linear density bending moment... Determined by the following formula:

[0016]

[0017] In the formula, This refers to the bending stiffness of the entire wall panel in the shot-peened area. The bending radius along the shot peening direction is measured by a rectangular test plate of the same material and thickness as the integral wall panel, after single-sided shot peening with the same parameters without prestress. The bending radius along the prestress direction is measured by a rectangular test plate made of the same material and thickness as the integral wall panel, after being shot-peened on one side with the same horizontal bending prestress as the integral wall panel and with the same shot-peening parameters. Let be the Poisson's ratio of the rectangular test plate material.

[0018] Furthermore, bending stiffness Calculated using the following formula:

[0019]

[0020] In the formula, The thickness of the rectangular test plate. Let be the elastic modulus of the rectangular test plate material.

[0021] Furthermore, in S3, for regions where the shot-peened surface is a double-sided shot-peened surface, the linear density bending moment on the side with higher shot-peening intensity is... and the linear density bending moment on the side with lower shot peening intensity They are determined using the following formulas respectively:

[0022]

[0023]

[0024] In the formula The bending radius along the shot peening direction of a rectangular test plate of the same material and thickness as the integral wall panel, under no prestress, after single-sided shot peening with the same shot peening parameters as the side with greater shot peening intensity. The bending radius along the shot peening direction of a rectangular test plate of the same material and thickness as the integral wall panel, under no prestress, after single-sided shot peening with the same shot peening parameters as the side with lower shot peening intensity. The bending radius along the prestress direction is measured by a rectangular test plate made of the same material and thickness as the integral wall panel, after being shot-peened on one side with the same shot-peening parameters as the side with the greater shot-peening intensity, under the same horizontal bending prestress as the integral wall panel. The bending radius along the prestress direction is the radius of a rectangular test plate made of the same material and thickness as the integral wall panel, after being shot peened on one side with the same shot peening parameters as the side with the lower shot peening intensity, under the same horizontal bending prestress as the integral wall panel.

[0025] Furthermore, for regions where the shot-peened surface is a double-sided shot-peened surface, the equivalent linear density bending moment... Calculated using the following formula:

[0026] .

[0027] Furthermore, for areas where the shot-peened surface is a double-sided shot-peened surface, the equivalent thermal load also needs to be applied, and the temperature change corresponding to the equivalent thermal load is... Determined by the following formula:

[0028]

[0029] In the formula, The coefficient of thermal expansion of the overall wall panel material.

[0030] Furthermore, in S4, the shell geometry model is discretized using shell elements, and the shell element types include: 3-node linear triangular shell elements, 6-node quadrilateral shell elements, 4-node linear quadrilateral shell elements, or 8-node quadrilateral shell elements.

[0031] Furthermore, in S4, the boundary constraint condition is to constrain six degrees of freedom at a node in the central region of the shell geometry model, the six degrees of freedom including three translational degrees of freedom and three rotational degrees of freedom.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0033] (1) Through systematic standard experiments, this invention establishes a direct and clear quantitative mapping relationship between shot peening process parameters, material thickness and equivalent mechanical load, which overcomes the shortcomings of the existing technology where the load definition is vague, relies on experience or complex simulation, and transforms the complex physical process of shot peening into a design input that can be accurately calculated, providing a reliable quantitative basis for process design and optimization.

[0034] (2) This invention equates the dynamic impact process of a large number of projectiles to a static linear elastic load acting on the shell model, transforming the complex nonlinear transient problem into a simple linear static problem. This reduces the simulation calculation time for meter-scale wall panels from hours to seconds, dramatically improving the calculation efficiency. At the same time, theoretical formulas and experimental calibration ensure a high degree of agreement between the simulation results and experimental data, combining high efficiency and high precision.

[0035] (3) This invention supports rapid virtual testing and iterative optimization of various shot peening schemes, realizes simulation-driven design, can effectively predict shot peening deformation, thereby significantly improving the first-time success rate of the process and reducing trial and error costs. At the same time, the method has a clear principle and is easy to integrate into general finite element software for implementation, and has good versatility and engineering promotion value. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the structure of the inner surface of the integral wall panel in an embodiment of the present invention;

[0037] Figure 2This is a schematic diagram of the structure of the outer surface of the integral wall panel in an embodiment of the present invention;

[0038] Figure 3 This is a schematic diagram of the shot peening area planning implemented on the inner surface of the integral wall panel in an embodiment of the present invention;

[0039] Figure 4 This is a schematic diagram of shot peening area planning implemented on the outer surface of the integral wall panel in an embodiment of the present invention.

[0040] Figure 5 This is a schematic diagram of the finite element mesh obtained after meshing the shell geometric model in an embodiment of the present invention;

[0041] Figure 6 This is a schematic diagram of the finite element mesh obtained after meshing the shell geometry model of test plate A. Detailed Implementation

[0042] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] Example

[0044] This embodiment proposes a finite element modeling method for shot peening forming analysis of integral wall panels, including the following steps:

[0045] S1. Establish the shell geometric model of the integral wall panel. The specific method is as follows:

[0046] S11. Extract the outer surface of the overall wall panel blank as the main body, and extract the geometric mid-surface of each reinforcing rib respectively. The geometric mid-surface is a curved surface located in the middle of the thickness of the reinforcing rib.

[0047] S12. Geometrically assemble the outer surface of the planar slab with the middle surface of each reinforcing rib to form a continuous shell geometric assembly. At the connection points of each segment, ensure that the deformation coordination constraints, i.e., displacement continuity, are met between the segments by using shared nodes or setting binding constraints.

[0048] S13. Set the thickness attributes of each part of the shell geometric assembly to obtain the shell geometric model. The thickness of the shell geometric model is completely consistent with that of the overall wall panel at the corresponding position.

[0049] In this embodiment, the integral wall panel is the 2024-T351 aluminum alloy integral wall panel shown, for reference. Figure 1 and Figure 2The inner surface of the wall panel has a reinforcing rib structure, and the outer surface is a skin surface. For simplicity, in this embodiment, the thickness of the entire wall panel is 6mm, and the height of the reinforcing ribs is 60mm.

[0050] S2. Based on the shot peening forming process, determine the areas on the integral wall panel that need to be shot peened and their corresponding shot peening conditions. The shot peening conditions include the shot peening surface, shot peening parameters, and whether prestress exists. The shot peening surface includes a single-sided shot peening surface or a double-sided shot peening surface.

[0051] The spraying area planning of the integral wall panel in this embodiment is referenced. Figure 3 and Figure 4 The details are as follows:

[0052] The areas to be subjected to double-sided shot peening are:

[0053] Inner surface region ① and its corresponding outer surface region ⑤;

[0054] Inner surface region ④ and its corresponding outer surface region ⑦;

[0055] Regions ② and ③ on the reinforcing rib; it should be noted that regions ② and ③ refer to the portion (i.e., the upper half) of the corresponding reinforcing rib, extending 30mm downwards from the top. During shot peening, both sides of this portion are shot peened. When establishing the shell geometry model, this shot-peening region corresponds to the corresponding segment on the geometric mid-surface of the reinforcing rib.

[0056] The area to be shot peened on one side is the outer surface area ⑥.

[0057] All shot-peened areas on the integral wall panel were not prestressed before shot peening.

[0058] In this embodiment, when performing double-sided shot peening, the shot peening parameters for the inner and outer surfaces are the same: shot flow rate = 12 kg / min, shot diameter = 3.18 mm, shot peening distance = 500 mm, shot peening air pressure = 0.20 MPa, and shot peening velocity = 4 m / min. This area has no prestress before shot peening.

[0059] When performing single-sided shot peening, the shot peening parameters are: shot flow rate = 12 kg / min, shot diameter = 3.18 mm, shot peening distance = 500 mm, shot peening air pressure = 0.25 MPa, and shot peening speed = 2 m / min.

[0060] In this step, the projectile is a cast steel projectile.

[0061] S3. Based on the shot peening conditions, determine the equivalent load in the corresponding region. The specific method is as follows:

[0062] S31. A rectangular plate of the same material and thickness (6mm) as the integral wall panel is used as the test plate. The aspect ratio of the test plate is ≥3, preferably 4~5. The elastic modulus, Poisson's ratio and coefficient of thermal expansion of the material used in the integral wall panel are measured according to GB / T228.1-2021 standard.

[0063] In this embodiment, the test plate is 200mm long and 50mm wide, and the elastic modulus of the 2024-T351 aluminum alloy used in the overall wall panel is measured. Poisson's ratio coefficient of thermal expansion .

[0064] The test plate was shot-peened on one side using the shot-peening parameters used in double-sided shot peening. The bending radius of the plate along the shot-peening direction after shot peening was measured to be 2.83m. In this embodiment, the shot-peening parameters of the inner and outer surfaces of the double-sided shot-peening area are the same, so the bending radius generated by shot peening on both sides is the same.

[0065] Using the same shot peening parameters as when performing single-sided shot peening, another test plate was shot peened on one side, and the bending radius was measured to be 1.53m.

[0066] S32. Calculate the bending stiffness of the integral wall panel in the shot-peened area. :

[0067]

[0068] In the formula, The thickness of the rectangular test plate;

[0069] In this embodiment:

[0070]

[0071] S32. Calculate the equivalent load in each shot peening region:

[0072] S321. For a double-sided shot-peened area, the equivalent load includes the equivalent linear density bending moment and the equivalent thermal load. The linear density bending moment on the side with the greater shot-peening intensity... and the linear density bending moment on the side with lower shot peening intensity They are determined using the following formulas respectively:

[0073]

[0074]

[0075] In the formula The bending radius along the shot peening direction of a rectangular test plate of the same material and thickness as the integral wall panel, under no prestress, after single-sided shot peening with the same shot peening parameters as the side with greater shot peening intensity. The bending radius along the shot peening direction of a rectangular test plate of the same material and thickness as the integral wall panel, under no prestress, after single-sided shot peening with the same shot peening parameters as the side with lower shot peening intensity. The bending radius along the prestress direction is measured by a rectangular test plate made of the same material and thickness as the integral wall panel, after being shot-peened on one side with the same shot-peening parameters as the side with the greater shot-peening intensity, under the same horizontal bending prestress as the integral wall panel. The bending radius along the prestress direction is the radius of a rectangular test plate made of the same material and thickness as the integral wall panel, after being shot peened on one side with the same shot peening parameters as the side with the lower shot peening intensity, under the same horizontal bending prestress as the integral wall panel.

[0076] In this embodiment, the inner and outer surfaces of the double-sided shot-peened areas (areas ①-④) have the same shot-peening parameters (i.e., the same shot-peening intensity), and there is no prestress before shot peening in any of the shot-peened areas. Therefore, for each pair of double-sided shot-peened areas, , .

[0077] because Therefore, the equivalent linear density bending moment .

[0078] The method for calculating the equivalent thermal load is as follows:

[0079]

[0080] Therefore, in this embodiment, shot peening is required in the double-sided shot peening area. The uniform temperature field is used as the equivalent thermal load.

[0081] S321. For a single-sided shot-peened area, the equivalent load is the equivalent linear density bending moment. :

[0082]

[0083] In the formula, The bending radius along the shot peening direction is measured by a rectangular test plate of the same material and thickness as the integral wall panel, after single-sided shot peening with the same parameters without prestress. The bending radius along the prestress direction is the value of a rectangular test plate made of the same material and thickness as the integral wall panel, after being shot peened on one side with the same horizontal bending prestress as the integral wall panel and with the same shot peening parameters.

[0084] In this embodiment Therefore .

[0085] Only an equivalent linear density bending moment needs to be applied to this area; no equivalent thermal load is required.

[0086] S4. Apply the equivalent load to the boundary of the corresponding region of the shell geometry model and apply constraints to establish a finite element model of the overall wall panel shot peening process; specifically including the following sub-steps:

[0087] S41. Discretize the shell geometric model established in S1 to generate, as shown below. Figure 5 The finite element mesh shown in this embodiment is specifically used to discretize the shell geometric model as follows: the shell geometric model is imported into ABAQUS finite element software, and the shell geometric model is meshed using 8-node quadrilateral shell elements (such as S8R elements) with a side length of 15mm.

[0088] S42. Create the material in the finite element software and assign it mechanical properties. In this embodiment, the material is 2024-T351 aluminum alloy, and the parameters are set as follows: elastic modulus... Poisson's ratio coefficient of thermal expansion .

[0089] S43. Apply the equivalent load determined in S3 to the boundary of the region corresponding to the shell geometric model. In this embodiment, the equivalent load is applied to the edge of the element set corresponding to the outer surface region ⑥. The equivalent linear density bending moment. Applying... A uniform temperature field;

[0090] Select a node in the middle of the shell geometry model and constrain all six degrees of freedom to eliminate rigid body displacement. The six degrees of freedom include three translational degrees of freedom and three rotational degrees of freedom.

[0091] S44. Create a static general analysis step in the finite element software and submit the calculation.

[0092] To verify the effectiveness of the modeling method of the present invention, rectangular test plates A and B, both made of 2024-T351 aluminum alloy, were used to conduct shot peening experiments. The dimensions of test plate A were 200 mm long, 50 mm wide, and 6 mm thick, and the dimensions of test plate B were 200 mm long, 50 mm wide, and 8 mm thick. Cast steel shot was used.

[0093] First, test plates A and B were shot-peened on one side using a shot peening machine. The shot peening parameters used were: shot flow rate = 12 kg / min, shot diameter = 3.18 mm, shot peening distance = 500 mm, and shot peening air pressure = 0.25 MPa. The shot-peened areas of test plates A and B had no prestress before shot peening. Different shot coverage rates were obtained by changing the shot peening speed of the machine (v = 2, 4, 6, 8 m / min). The bending radius of test plates A and B after shot peening under each experimental condition was measured.

[0094] Following the process described in the above embodiments, finite element modeling was performed on the shot peening forming process of test plate A and test plate B respectively, and the bending radius of test plate A and test plate B under the corresponding experimental conditions was calculated. Figure 6 The finite element mesh obtained after discretizing the shell geometry model of test plate A is shown.

[0095] The bending radius measured after shot peening of the machine tool and the bending radius calculated by the finite element model are shown in Table 1.

[0096] Table 1. Experimental and simulation results of shot peening forming on the test plate.

[0097]

[0098] As can be seen from Table 1, for specimens of different thicknesses and process conditions with different shot peening intensities, the bending radius calculated by the finite element model established by the method of this invention is completely consistent with the experimentally measured bending radius within the range of the investigated accuracy (0.01m). Therefore, the finite element modeling method proposed in this invention can accurately quantify the mapping relationship between shot peening process parameters and structural deformation, and realize high-precision prediction of shot peening forming results.

[0099] The specific embodiments of the present invention are provided to enable those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention.

[0100] It should be understood that the present invention is not limited to the content already described above, and various modifications and changes can be made without departing from its scope. The scope of the present invention is limited only by the appended claims.

Claims

1. A finite element modeling method for shot peening forming analysis of integral wall panels, characterized in that, Includes the following steps: S1. Establish the shell geometric model of the integral wall panel, wherein the thickness of the shell geometric model is consistent with the thickness of the corresponding position of the integral wall panel; S2. Based on the shot peening forming process, determine the area on the integral wall panel that needs to be shot peened and its corresponding shot peening conditions. The shot peening conditions include at least the shot peening surface, shot peening parameters, and whether prestress exists. S3. Based on the shot peening conditions, determine the equivalent load for the corresponding area. The equivalent load includes at least one of equivalent linear density bending moment and equivalent thermal load. The equivalent linear density bending moment is used to simulate the bending deformation of the integral wall panel during the shot peening process, and the equivalent thermal load is used to simulate the elongation deformation of the integral wall panel during the shot peening process. S4. Apply the equivalent load to the boundary or element of the corresponding region of the shell geometry model and apply constraints to establish a finite element model of the overall wall panel shot peening forming.

2. The finite element modeling method for shot peening forming analysis of integral wall panels according to claim 1, characterized in that, In S1, the shell geometric model is composed of the outer surface of the integral wall panel slab and the geometric mid-surface of the reinforcing rib, and the deformation coordination constraints are satisfied at the connection between the segments.

3. The finite element modeling method for shot peening forming analysis of integral wall panels according to claim 1, characterized in that, In S2, the shot-peened surface includes a single-sided shot-peened surface or a double-sided shot-peened surface.

4. The finite element modeling method for shot peening forming analysis of integral wall panels according to claim 3, characterized in that, In S3, for regions where the shot-peened surface is a single-sided shot-peened surface, the equivalent linear density bending moment... Determined by the following formula: In the formula, This refers to the bending stiffness of the entire wall panel in the shot-peened area. The bending radius along the shot peening direction is measured by a rectangular test plate of the same material and thickness as the integral wall panel, after single-sided shot peening with the same parameters without prestress. The bending radius along the prestress direction is measured by a rectangular test plate made of the same material and thickness as the integral wall panel, after being shot-peened on one side with the same horizontal bending prestress as the integral wall panel and with the same shot-peening parameters. Let be the Poisson's ratio of the rectangular test plate material.

5. The finite element modeling method for shot peening forming analysis of integral wall panels according to claim 4, characterized in that, Bending stiffness Calculated using the following formula: In the formula, The thickness of the rectangular test plate. Let be the elastic modulus of the rectangular test plate material.

6. The finite element modeling method for shot peening forming analysis of integral wall panels according to claim 3, characterized in that, In S3, for regions where the shot-peened surface is a double-sided shot-peened surface, the linear density bending moment on the side with higher shot-peening intensity is... and the linear density bending moment on the side with lower shot peening intensity They are determined using the following formulas respectively: In the formula The bending radius along the shot peening direction of a rectangular test plate of the same material and thickness as the integral wall panel, under no prestress, after single-sided shot peening with the same shot peening parameters as the side with greater shot peening intensity. The bending radius along the shot peening direction of a rectangular test plate of the same material and thickness as the integral wall panel, under no prestress, after single-sided shot peening with the same shot peening parameters as the side with lower shot peening intensity. The bending radius along the prestress direction is measured by a rectangular test plate made of the same material and thickness as the integral wall panel, after being shot-peened on one side with the same shot-peening parameters as the side with the greater shot-peening intensity, under the same horizontal bending prestress as the integral wall panel. The bending radius along the prestress direction is the radius of a rectangular test plate made of the same material and thickness as the integral wall panel, after being shot peened on one side with the same shot peening parameters as the side with the lower shot peening intensity, under the same horizontal bending prestress as the integral wall panel.

7. The finite element modeling method for shot peening forming analysis of integral wall panels according to claim 6, characterized in that, For regions where the shot-peened surface is double-sided, the equivalent linear density bending moment Calculated using the following formula: 。 8. The finite element modeling method for shot peening forming analysis of integral wall panels according to claim 6, characterized in that, For areas where the shot-peened surface is double-sided, the equivalent thermal load also needs to be applied, and the temperature change corresponding to the equivalent thermal load is... Determined by the following formula: In the formula, The coefficient of thermal expansion of the overall wall panel material.

9. The finite element modeling method for shot peening forming analysis of integral wall panels according to claim 1, characterized in that, In S4, the shell geometry model is discretized using shell elements. The shell element types include: 3-node linear triangular shell elements, 6-node quadratic triangular shell elements, 4-node linear quadrilateral shell elements, or 8-node quadrilateral shell elements.

10. The finite element modeling method for shot peening forming analysis of integral wall panels according to claim 1, characterized in that, In S4, the boundary constraint condition is to constrain six degrees of freedom at a node in the middle region of the shell geometry model, including three translational degrees of freedom and three rotational degrees of freedom.

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