Non-ribbed wing wallboard torsion shape shot peening forming method

Abstract

The invention belongs to the technical field of shot peening forming of aircraft wing wallboards, and particularly relates to a non-ribbed wing wallboard torsion appearance shot peening forming method which comprises the following steps: step 1, carrying out spanwise pre-bending clamping on a torsion appearance area; secondly, chordwise shot peening forming is conducted on the outer surface of the torsion shape area; thirdly, spanwise shot peening forming is conducted on the inner surface of the torsion shape area; fourthly, torsion shape pre-bending clamping is conducted on the torsion shape area; and 5, equal-pressure opposite spraying is conducted on the inner surface and the outer surface of the torsion shape area.

Description

Technical Field

[0001] The invention belongs to the technical field of shot peening forming of aircraft wing panels, and in particular relates to a shot peening forming method for a twisted shape of a wing panel without ribs. Background Art

[0002] Shot peening is a plastic forming method that uses high-speed projectile flow to impact the surface of the part to produce a plastic strain layer on the surface material, thereby causing favorable changes in the microstructure of the layer and introducing a residual compressive stress layer on the surface, thereby causing the part to undergo plastic deformation to obtain the required shape. Shot peening is particularly suitable for processing medium and large aircraft wing panels, especially complex hyperbolic wing panels. At present, most wing panels have a hyperbolic shape, that is, they have both chord and span curvatures, that is, they have both chord and span shapes. Due to the aerodynamic shape requirements of the aircraft wing, the angle of attack of the wing tip is smaller than that of the wing root, which results in the overall torsion of the wing panel. It can be said that almost all complex hyperbolic wing panels have a certain degree of torsion, and the torsion shape is a comprehensive expression of the simultaneous action of the chord and span curvature of the wing panel. At present, for ribbed wall panels, since the whole is a rigid composite structure of web + ribs, the chord shape can be obtained by web shot peening during shot peening, and the span shape can be obtained by rib shot peening. The two are performed independently, so the rib shot peening has little effect on the web shot peening. When the span shape of all ribs meets the requirements, the wall panel has both chord and span hyperbolic shapes, that is, the required torsional shape is obtained. However, for unribbed wall panels, the whole is a single web structure, and the chord and span shapes must be obtained by web shot peening. The current method is to first perform chord shot peening on the web, that is, the outer surface of the wall panel, and then perform span shot peening on the inner surface of the wall panel. Since the torsional shape of the wall panel is most severe at the upper and lower edges, only the thickened strip areas at the upper and lower edges of the wall panel are subjected to span shot peening. The span deformation of the upper and lower edges drives the wall panel to produce overall span deformation. Finally, according to the torsional shape forming principle of the ribbed wall panel, shot peening and correction are performed at the axis of the long girder on the inner surface of the wall panel until the shape of the wall panel meets the requirements under the loading state. Although the above method can produce a certain torsional shape of the wall panel, since the spanwise shot peening area of ​​the inner surface only has two strips on the upper and lower edges, it is impossible to drive the wall panel as a whole to produce the required spanwise deformation, resulting in insufficient torsional shape of the wall panel. After shot peening, it can only be loaded to the limit within the required range. Although it can meet the requirements, there is a large stress when assembling the wall panel, and the assembly coordination is poor, and it often needs to be repaired. At the same time, the correction of the shape on the inner surface of the wall panel will inevitably offset the chordal shape produced by shot peening on the outer surface, and even cause chordal reverse forming. At this time, it is necessary to correct the chordal shape on the outer surface again, and then correct the spanwise shape on the inner surface, gradually approaching until the final shape is reached. However, such repeated corrections can easily cause the wall panel to become unstable due to excessive extension of the material, resulting in irreversible consequences. Therefore, a new and efficient torsional shape shot peening forming method is urgently needed to solve the technical difficulties and risks existing in the torsional shape forming of unreinforced wall panels at present, and further improve the level of shot peening forming technology. Summary of the invention

[0003] Purpose of the invention: In order to solve the above-mentioned problem of shot peening forming of the torsional shape of unreinforced wing panels, the present invention provides a method for shot peening forming of the torsional shape of unreinforced wing panels, by performing chord-wise shot peening forming on the outer surface of the torsional area in the spanwise pre-bending state and performing spanwise shot peening forming on the thickened strip areas at the upper and lower edges of the inner surface, so that the panel obtains the desired chord-wise shape and preliminary spanwise shape, that is, obtains the preliminary torsional shape, then the panel is torsionally pre-bent and clamped, so that the panel produces torsional pre-deformation, that is, generates torsional deformation inducing force, and finally the inner and outer surfaces in the torsional area are subjected to equal pressure spraying, so that the inner surface material of the panel produces spanwise extension in the state that the chord-wise shape of the panel remains unchanged to obtain the desired spanwise shape, and finally the panel obtains the chord-wise and spanwise hyperbolic shape, that is, forms the desired torsional shape. Summary of the invention:

[0005] A method for shot peening a torsion profile of a wing panel without ribs, comprising the following steps:

[0006] Step 1: Pre-bend and clamp the torsion shape area in span direction;

[0007] Step 2: Perform chord-wise shot peening on the outer surface of the torsion shape area;

[0008] Step 3: Shot peening the inner surface of the twisted shape area in the span direction;

[0009] Step 4: Pre-bend and clamp the torsion shape area;

[0010] Step 5: Spray the inner and outer surfaces of the torsion shape area with equal pressure.

[0011] Furthermore, in step 1, in order to improve the deformation capacity of the wall panel in the span direction by shot peening and suppress the "spherical deformation" effect during the chord direction shot peening, the wall panel is pre-bent and clamped in the span direction, and the clamping process is as follows:

[0012] A load-bearing column is set at the left and right boundaries of the torsion area on the inner surface of the wall panel, and a force-applying column is set at 400mm on the outer surface away from the left and right boundaries to form a "four-point" pre-bending clamp, so that the torsional shape area of ​​the wall panel can obtain uniform pre-deformation; the wall panel is pre-bent in the span direction at the same time through the two force-applying columns on the outer surface, so that the wall panel is bent toward the inner surface; further, the span direction curvature of each point on the force-applying column during pre-bending is twice the curvature.

[0013] Furthermore, in step 2, in order to make the outer surface of the wall panel obtain a chord-wise shape that meets the requirements, the outer surface is subjected to chord-wise shot peening, the starting point of the shot peening path is the lower right corner of the part, the starting direction is horizontal to the right and then bends upward, and then rotary shot peening is performed along the direction of maximum curvature or minimum curvature. The shot peening path rotates after exceeding the part boundary by a distance L1; the value range of L1 is 150mm~200mm; the distance between the two shot peening paths is D; the value range of D is 80mm~120mm.

[0014] Furthermore, in step three, in order to obtain the desired spanwise deformation in the torsional shape area of ​​the wall panel and initially form a torsional shape while reducing the impact on the already formed chordal shape, the wall panel is subjected to spanwise shot peening. During shot peening, only the thickened strip area on the inner surface near the upper and lower edges of the torsional shape area of ​​the wall panel is shot peened, and the width of the shot peening strip is L2; ​​the value range of L2 is 80mm to 100mm; the thickened strip area is an area with a thickness not less than H, and the value range of H is ≥6mm.

[0015] Furthermore, in step 4, in order to make the torsion area of ​​the wall panel further obtain the desired torsion shape, the wall panel is pre-bent and clamped in a torsion shape, and the clamping process is as follows:

[0016] A force-applying column is arranged on the inner and outer surfaces of the left boundary of the torsion shape area of ​​the wall panel; a force-applying screw is installed on the inner surface force-applying column at the upper edge of the wall panel, and a force-applying screw is installed on the outer surface force-applying column at the lower edge of the wall panel. The inner and outer surface screws apply force to the wall panel at the same time, so that the left boundary of the torsion area of ​​the wall panel tilts from right to left, and the tilting angle is the same as the torsion angle of the wall panel;

[0017] A force column is arranged on the inner and outer surfaces at a position 400mm inward from the right boundary of the torsion shape area of ​​the wall panel; a force screw is installed on the inner surface force column at a position corresponding to the lower edge of the wall panel, and a force screw is installed on the outer surface force column at a position corresponding to the upper edge of the wall panel. The inner and outer surface screws apply force to the wall panel at the same time, so that the right boundary of the torsion area of ​​the wall panel tilts from left to right, and the inclination angle is the same as the torsion angle of the wall panel.

[0018] Further, the force screw is set at the following position:

[0019] At the left boundary, the position of the force screw on the inner surface force column contacts the upper edge thickened area on the inner surface of the wall panel, that is, 30mm to 40mm away from the upper edge, and the position of the force screw on the outer surface force column contacts the outer surface corresponding to the lower edge thickened area of ​​the wall panel, that is, 20m to 30mm away from the lower edge; at the right boundary, the position of the force screw on the inner surface force column contacts the lower edge thickened area on the inner surface of the wall panel, that is, 20mm to 30mm away from the lower edge, and the position of the force screw on the outer surface force column contacts the outer surface corresponding to the upper edge thickened area of ​​the wall panel, that is, 30m to 40mm away from the upper edge.

[0020] Furthermore, in step five, in order to fully extend the inner and outer surface materials in the torsional shape area of ​​the wall panel, obtain the required torsional deformation and reduce the influence on the formed chordal shape, the inner and outer surfaces in the torsional shape area are subjected to equal pressure shot peening, and 3 to 5 shot peening strips are selected for shot peening; the length direction of the shot peening strip is the same as the chordal curvature direction; the width of the shot peening strip is 80m to 100mm; the strip spacing is 80m to 120mm.

[0021] Furthermore, the parameters of equal pressure spraying are as follows:

[0022] Shot peening medium and size: φ3.18mm~φ4.8mm carburized steel shot; shot peening pressure: 0.25Mpa~0.30Mpa; shot peening flow rate: 8kg / min~12kg / min; shot peening distance: 400mm~500mm; shot peening speed: 4m / min~6m / min.

[0023] The beneficial effects of this application are:

[0024] A torsional shape shot peening method is provided for wing panels without ribs. By sequentially performing chord-wise shot peening on the outer surface of the torsional region and performing span-wise shot peening on the thickened strip areas at the upper and lower edges of the inner surface in a span-wise pre-bending state, the panel obtains a desired chord-wise shape and a preliminary span-wise shape, i.e., a preliminary torsional shape. The panel is then pre-bent and clamped in a torsional shape to generate a torsional deformation inducing force. Finally, equal-pressure shot peening is performed on the inner and outer surfaces in the torsional region to ensure that the chord-wise shape of the outer surface remains unchanged under the action of the torsional deformation inducing force, while the inner surface material is extended in the span-wise direction to promote span-wise deformation. Finally, the panel has a chord-wise and span-wise hyperbolic shape that meets the design requirements, i.e., the desired torsional shape is formed, thereby effectively solving the problems of insufficient torsional shape and large assembly stress in shot peening of panels without ribs, and avoiding the risk of instability during panel correction. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of spanwise pre-bending clamping in the torsion profile area;

[0026] Figure 2 Schematic diagram of chord-wise shot peening of the outer surface of the twisted shape area;

[0027] Figure 3 Schematic diagram of the spanwise shot peening of the inner surface of the twisted shape area;

[0028] Figure 4 Schematic diagram of torsion pre-bending clamping;

[0029] Figure 5 Schematic diagram of spraying on the outer surface in the twisting area;

[0030] Explanation of numbers in the figure: 1. Oblique load-bearing column; 2. Vertical load-bearing column; 3. Vertical force-applying column; 4. Oblique force-applying column; 5. Chordal path; 6. Lower edge thickened strip area; 7. Upper edge thickened strip area; 8. Force screw; 9. Spraying strip area. DETAILED DESCRIPTION

[0031] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0032] The terms "first", "second", etc. in the specification and claims of the present invention are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of the same type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0033] A method for shot peening a torsion profile of a wing panel without ribs, comprising the following steps:

[0034] Step 1: Pre-bend and clamp the twisted shape area in span direction:

[0035] Since the torsion area of ​​the wall panel is in the shape of a "saddle", that is, the spanwise bending is toward the inner surface and the chordwise bending is toward the outer surface, during clamping, firstly, a load-bearing column is set at the left and right boundaries of the torsion area on the inner surface of the wall panel, and then a force-applying column is set at 400mm away from the left and right boundaries of the load-bearing columns on the outer surface, forming a "four-point" pre-bending clamping, so that the torsion area can obtain the required pre-bending amount, and finally, the wall panel is pre-bent in the spanwise direction at the same time through the two force-applying columns on the outer surface, so that the wall panel is bent toward the inner surface. During pre-bending, the pre-bending amount at the force-applying column, that is, the spanwise curvature is twice the required amount.

[0036] Step 2: Shot peening the outer surface of the torsion shape area in the chord direction:

[0037] The outer surface of the torsional shape area of ​​the wall panel is subjected to chordwise shot peening in the spanwise pre-bending state to obtain the desired chordwise shape and suppress the deformation of the shot peening spherical surface, that is, the spanwise reverse deformation of the wall panel is suppressed during chordwise forming. At the same time, in order to make the deformation in the chordwise direction of the wall panel consistent with the torsional deformation trend, shot peening is carried out along the chordwise curvature distribution direction of the wall panel, that is, along the chordal path.

[0038] The starting point of the shot peening path is the lower right corner of the part. The starting direction is horizontal to the right and then bends upward. Then, the shot peening is performed in the direction of maximum curvature or minimum curvature. The shot peening path rotates after exceeding the part boundary by a distance of L1; the value range of L1 is 150mm~200mm; the distance between the two shot peening paths is D; the value range of D is 80mm~120mm.

[0039] Step 3: Shot peening the inner surface of the twisted shape area in the span direction:

[0040] The inner surface of the wall panel is shot peened in the spanwise direction under the spanwise pre-bending state. Since the torsional shape of the wall panel is most severe at the upper and lower edges, and the spanwise shape at the upper and lower edges has no effect on the overall chordwise shape of the wall panel, only the thickened strip area on the inner surface near the upper and lower edges of the torsional shape area of ​​the wall panel is shot peened during the spanwise shot peening. The width of the shot peening strip is L2; ​​the value range of L2 is 80mm~100mm; before shot peening, the adjacent area of ​​the shot peening strip is protected. After shot peening, the wall panel initially obtains the spanwise shape while the overall chordwise shape remains unchanged, that is, the torsional shape of the wall panel is initially formed.

[0041] Step 4: Pre-bend and clamp the torsion shape area:

[0042] A force-applying column is set on the inner and outer surfaces of the left boundary of the torsion shape area of ​​the wall panel, wherein a force-applying screw is installed on the inner surface force-applying column at the thickened area of ​​the upper edge of the wall panel, and the screw is 30mm to 40mm away from the upper edge; a force-applying screw is installed on the outer surface force-applying column at the thickened area of ​​the lower edge of the wall panel, and the screw is 20mm to 30mm away from the lower edge. The inner and outer surface screws apply force to the wall panel at the same time, so that the left boundary of the torsion shape area of ​​the wall panel tilts from right to left, and the tilt angle is the same as the torsion angle of the wall panel; similarly, the inner and outer surfaces at the right boundary of the torsion shape area of ​​the wall panel are Each is provided with one force column, wherein one force screw is installed on the inner surface force column at the thickened area of ​​the lower edge of the wall panel, and the distance between the screw and the lower edge is 20mm to 30mm; one force screw is installed on the outer surface force column at the thickened area of ​​the upper edge of the wall panel, and the distance between the screw and the upper edge is 30mm to 40mm. The inner and outer surface screws simultaneously apply force to the wall panel, so that the right boundary of the torsion area of ​​the wall panel tilts from left to right, and the inclination angle is the same as the torsion angle of the wall panel. At this time, the inclination directions of the left and right boundaries of the wall panel are opposite, so that the wall panel as a whole presents a torsion shape and the torsion angle is twice the requirement.

[0043] Step 5: Spray the inner and outer surfaces of the twisted shape area with equal pressure:

[0044] In the torsional pre-bending clamping state, the inner and outer surfaces of the torsional area are shot peened, with 3 to 5 shot peening strips and a strip spacing of 80m to 120mm. The direction of the shot peening strips is consistent with the direction of the chordal curvature. Since the wall panel already has a chordal shape during the shot peening, if the shot peening parameters of the inner and outer surfaces are inconsistent, that is, there is a shot peening pressure difference, the chordal curvature of the wall panel after shot peening will inevitably change. At the same time, according to the torsional shape forming principle of the ribbed wall panel, the inner surface material must be extended along the span direction while the chordal curvature of the outer surface remains unchanged during forming. Therefore, when the torsional shape area is shot peened, the inner and outer surfaces are subjected to equal pressure difference, so that under the action of the torsional deformation induced force, the wall panel can ensure that the chordal shape of the outer surface remains unchanged, and the inner surface material can be extended along the span direction to promote spanwise deformation, so that the wall panel finally has a chordal-span hyperbolic shape that meets the design requirements, that is, the required torsional shape is formed.

[0045] Example

[0046] like Figure 1-5 As shown, the specific implementation mode of the present invention is described below by taking a typical torsion area of ​​a wing panel without ribs of a certain aircraft as an example.

[0047] 1. Pre-bend and clamp the torsional shape area of ​​the wall panel in the span direction. Since the torsional shape area of ​​the unreinforced wall panel is usually in the shape of a "saddle", that is, the span direction is bent toward the inner surface and the chord direction is bent toward the outer surface, when clamping, first set an inclined load-bearing column 1 and a straight load-bearing column 2 at the left and right boundaries of the torsional shape area on the inner surface of the wall panel, and then set an inclined force column 4 at 400mm from the left boundary on the outer surface, and set a straight force column 3 at 400mm from the right boundary on the outer surface. Finally, the wall panel is pre-bent in the span direction by the straight force column 3 and the inclined force column 4 on the outer surface at the same time, so that the wall panel is bent toward the inner surface. During the pre-bending, the pre-bending amount at the straight force column 3 and the inclined force column 4, that is, the span direction curvature is twice the design requirement, to ensure that the deformation of the wall panel is within the elastic range.

[0048] 2. Shot peening is performed on the outer surface of the torsion shape area of ​​the wall panel in the chord direction. In the spanwise pre-bending state, the outer surface of the torsion shape area of ​​the wall panel is shot peened in the chord direction to obtain the desired chordwise shape and suppress the deformation of the shot peening sphere, that is, suppress the reverse deformation of the wall panel in the spanwise direction during chordwise forming. At the same time, in order to make the deformation in the chord direction of the wall panel consistent with the torsional deformation trend, shot peening is performed along the chordwise curvature distribution direction of the wall panel, that is, along the chordwise path 5.

[0049] 3. Shot peening is performed on the inner surface of the torsion shape area. The inner surface is shot peened in the spanwise direction in the spanwise pre-bending state. Since the torsion shape of the wall panel is most severe at the upper and lower edges, and the spanwise shape at the upper and lower edges has no effect on the overall chordal shape of the wall panel, only the lower edge thickened strip area 6 and the upper edge thickened strip area 7 of the inner surface of the torsion area of ​​the wall panel are shot peened during the spanwise shot peening. The width of the shot peening strip is 80mm. The adjacent areas of the shot peening strip are protected during shot peening. After shot peening, the wall panel initially obtains the spanwise shape while the overall chordal shape state remains unchanged, that is, the torsion shape of the wall panel is initially formed.

[0050] 4. Perform torsional pre-bending clamping on the torsional shape area. An inclined force column 4 is respectively arranged on the inner and outer surfaces at the left boundary of the torsion shape area of ​​the wall panel, wherein a force screw 8 is installed on the inner surface inclined force column 4 at the corresponding upper edge of the wall panel, and a force screw 8 is installed on the outer surface inclined force column 4 at the corresponding lower edge of the wall panel. The inner and outer surface force screws 7 simultaneously apply force to the wall panel, so that the left boundary of the torsion area of ​​the wall panel tilts from right to left, and the inclination angle is the same as the torsion angle of the wall panel; similarly, a straight force column 3 is respectively arranged on the inner and outer surfaces at the right boundary of the torsion shape area of ​​the wall panel, wherein a force screw 8 is installed on the inner surface straight force column 3 at the corresponding lower edge of the wall panel, and a force screw 8 is installed on the outer surface straight force column 3 at the corresponding upper edge of the wall panel. The inner and outer surface force screws 8 simultaneously apply force to the wall panel, so that the right boundary of the torsion area of ​​the wall panel tilts from left to right, and the inclination angle is the same as the torsion angle of the wall panel. At this time, the inclination directions of the left and right boundaries of the wall panel are opposite, so that the wall panel as a whole presents a torsion shape and the torsion angle is twice the required one.

[0051] 5. Perform equal pressure spraying on the inner and outer surfaces of the torsional shape area. In the torsional pre-bending clamping state, spray the inner and outer surfaces of the torsional shape area of ​​the wall panel. Select 3 strips from the 9 spraying strips, and the strip spacing is 120mm. The direction of the 9 spraying strips is consistent with the direction of the chordal curvature. Since the wall panel already has a chordal shape during the spraying, if the shot peening parameters of the inner and outer surfaces are inconsistent, that is, there is a shot peening pressure difference, the chordal curvature of the wall panel after shot peening will inevitably change. At the same time, according to the torsional shape forming principle of the ribbed wall panel, the inner surface material must be extended along the span direction while the chordal curvature of the outer surface remains unchanged during the forming. Therefore, when spraying the torsional shape area, the inner and outer surfaces are subjected to equal pressure, so that under the action of the torsional deformation induction force, the wall panel can not only ensure that the chordal shape of the outer surface remains unchanged, but also extend the inner surface material along the span direction to promote span deformation, and finally make the wall panel have a chordal span hyperbolic shape that meets the design requirements, that is, the required torsional shape is formed.

[0052] Through the implementation of the above steps, the problems of insufficient torsional shape, large assembly stress and easy instability during correction in the shot peening of un-ribbed wing panels have been successfully solved, a technological breakthrough in torsional shape shot peening has been achieved, and the technical gap in conventional shot peening in torsional shape shot peening of un-ribbed wing panels has been filled, greatly improving the technical level of shot peening.

[0053] It should be noted that, in this article, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element. In addition, it should be pointed out that the scope of the method and device in the embodiment of the present invention is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in reverse order according to the functions involved, for example, the described method may be performed in an order different from that described, and various steps may also be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0054] Through the description of the above implementation modes, those skilled in the art can clearly understand that the above implementation modes can be implemented by means of software plus a necessary general hardware platform, and of course by means of hardware, but in many cases the former is a better implementation mode. The above describes the embodiments of the present invention in conjunction with the accompanying drawings, but the present invention is not limited to the above specific implementation modes, which are merely illustrative and not restrictive. Under the enlightenment of the present invention, those skilled in the art can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. A method for shot peening the twisted shape of a wing panel without ribs, characterized in that: The following steps are involved: Step 1: Pre-bend and clamp the torsion shape area in span direction; Step 2: Perform chord-wise shot peening on the outer surface of the torsion shape area; Step 3: Shot peening the inner surface of the twisted shape area in the span direction; Step 4: Pre-bend and clamp the torsion shape area; Step 5: Spray the inner and outer surfaces of the torsion shape area with equal pressure.

2. The method according to claim 1, characterized in that: In step 1, the spanwise pre-bending clamping process is as follows: A load-bearing column is set at the left and right boundaries of the torsion area on the inner surface of the wall panel, and a force-applying column is set at 400mm from the left and right boundaries on the outer surface to form a "four-point" pre-bending clamp; the wall panel is pre-bent in the span direction at the same time through the two force-applying columns on the outer surface, so that the wall panel is bent toward the inner surface.

3. The method according to claim 2, characterized in that: During pre-bending, the spanwise curvature of each point on the force-applying column is twice the curvature.

4. The method according to claim 3, characterized in that: In step 2, the starting point of the shot peening path is the lower right corner of the part, the starting direction is horizontal to the right and then bends upward, and then the shot peening is performed in the direction of maximum curvature or minimum curvature. The shot peening path rotates after exceeding the part boundary by a distance of L1; the value range of L1 is 150mm~200mm; the distance between the two shot peening paths is D; the value range of D is 80mm~120mm.

5. The method according to claim 4, characterized in that: In step three, during spanwise shot peening deformation, only the thickened strip area near the upper and lower edges of the inner surface of the torsion shape area of ​​the wall panel is shot peened, and the width of the shot peening strip is L2; ​​the value range of L2 is 80mm~100mm; the thickened strip area is an area with a thickness not less than H, and the value range of H is ≥6mm.

6. The method according to claim 5, characterized in that: In step 4, the torsional pre-bending clamping process is as follows: A force-applying column is arranged on the inner and outer surfaces of the left boundary of the torsion shape area of ​​the wall panel; a force-applying screw is installed on the inner surface force-applying column at the upper edge of the wall panel, and a force-applying screw is installed on the outer surface force-applying column at the lower edge of the wall panel. The inner and outer surface screws apply force to the wall panel at the same time, so that the left boundary of the torsion area of ​​the wall panel tilts from right to left, and the tilting angle is the same as the torsion angle of the wall panel; A force column is arranged on the inner and outer surfaces at a position 400mm inward from the right boundary of the torsion shape area of ​​the wall panel; a force screw is installed on the inner surface force column at a position corresponding to the lower edge of the wall panel, and a force screw is installed on the outer surface force column at a position corresponding to the upper edge of the wall panel. The inner and outer surface screws apply force to the wall panel at the same time, so that the right boundary of the torsion area of ​​the wall panel tilts from left to right, and the inclination angle is the same as the torsion angle of the wall panel.

7. The method according to claim 6, characterized in that: The force screw is set as follows: At the left boundary, the position of the force screw on the inner surface force column contacts the upper edge thickened area on the inner surface of the wall panel, 30mm to 40mm away from the upper edge, and the position of the force screw on the outer surface force column contacts the outer surface corresponding to the lower edge thickened area of ​​the wall panel, 20m to 30mm away from the lower edge; at the right boundary, the position of the force screw on the inner surface force column contacts the lower edge thickened area on the inner surface of the wall panel, 20mm to 30mm away from the lower edge, and the position of the force screw on the outer surface force column contacts the outer surface corresponding to the upper edge thickened area of ​​the wall panel, 30m to 40mm away from the upper edge.

8. The method according to claim 7, characterized in that: In step five, when equal pressure peening is performed, 3 to 5 shot peening strips are selected; the length direction of the shot peening strip is the same as the chordal curvature direction; the width of the shot peening strip is 80m to 100mm; the strip spacing is 80m to 120mm.

9. The method according to claim 8, characterized in that: The parameters of equal pressure spraying are as follows: Shot peening medium and size: φ3.18mm~φ4.8mm carburized steel shot; shot peening pressure: 0.25Mpa~0.30Mpa; shot peening flow rate: 8kg / min~12kg / min; shot peening distance: 400mm~500mm; shot peening speed: 4m / min~6m / min.

Images