A complementary repair method

Abstract

This invention discloses a complementary shaping method. This method adopts a "positive interactive compensation" strategy, which suppresses the springback deformation of the stringer in the vertical axis through springback compensation, and suppresses the warping deformation of the stiffened wall panel in the stringer axis through mold compensation. The two are coupled to significantly reduce the solidification deformation of the stiffened wall panel.

Description

Technical Field

[0001] This invention relates to the field of composite material component manufacturing, and in particular to a complementary modification method. Background Technology

[0002] Composite stiffened panels are widely used in aircraft wings, tail fins, and other components. The anisotropy of the composite material itself, along with the complex layup structure of the stiffened panels, together cause the stiffened panels to exhibit complex hyperbolic curing deformation.

[0003] There are two main types of existing methods to suppress curing deformation of reinforced wall panels: 1) narrowing the process window such as heating and cooling rates to reduce the difference in curing stress inside the reinforced wall panel; 2) adopting mold modification compensation measures to reduce the curing deformation of the reinforced wall panel.

[0004] The first method increases the difficulty of controlling the manufacturing process, prolongs the curing cycle, and may even affect the overall performance of the stiffened panel. The second method can effectively alleviate the curing deformation of the stiffened panel.

[0005] Patent CN202210748618.0, entitled "A Method for Surface Compensation Control of Composite Material T-Shaped Parts," reduces the curing deformation of the stiffened panel by compensating for the springback deformation of the T-shaped stringer. Patent CN202311270504.0, entitled "A Mold Compensation Method for Curing Deformation of Stiffened Panels," suppresses curing deformation by compensating for the curing mold of the stiffened panel. In other words, existing methods divide the stiffened panel into two relatively independent parts: the stringer and the skin, without fully considering their coupling effect. Therefore, the compensation process is complex and the actual effect is unsatisfactory.

[0006] Therefore, there is an urgent need for a complementary modification method that fully considers the curing deformation of the stringers and skin themselves and their coupling effect, simplifies the process, and improves the suppression effect on the curing deformation of the stiffened wall panels. Summary of the Invention

[0007] This invention discloses a complementary shaping method. This method comprehensively considers the curing deformation of the stringer and skin themselves, as well as their coupling effect. It employs a "positive-reciprocal compensation" strategy, using rebound compensation to suppress the springback deformation of the stringer in the vertical axis, and mold compensation to suppress the warping deformation of the stiffened panel in the stringer axis. These two approaches complement each other, achieving a significant reduction in the curing deformation of the stiffened panel. This method is simple, efficient, and effectively suppresses the curing deformation of the stiffened panel.

[0008] A complementary shaping method, in which the shaping sections of the stringer and skin are perpendicular to each other, includes the following steps:

[0009] 1. In the thickest region of each girder, arbitrarily cut a cross-section along the girder axis. Extend the non-bonded bottom edge towards the vertical reinforcement, and extend the non-aligned vertical reinforcement towards the bottom edge. The two intersect at point P1, forming a theoretical angle θ0. With point P1 as the center, fix the non-aligned vertical reinforcement surface and rotate the non-bonded bottom edge surface in the opposite direction of the girder's springback deformation until it forms an angle θ1 with the non-aligned vertical reinforcement surface. The angle of rotation of the non-bonded bottom edge surface is θ, i.e., θ = |θ0 - θ1|. Use θ as the compensation angle for the springback deformation of the girder's curing mold, θ = θ0 / T max +1 / R max , among which, T max R is the highest curing temperature. max The maximum R value on the outer side of the stringer;

[0010] 2. Extend all the long girder of the stiffened panel along the girder axis to both sides until they are the same length as the two ends of the skin. Select the longest girder after extension, and cut the skin of the stiffened panel with the girder axis of this girder. Connect the endpoints P2 and P3 on both sides of the skin at the section to form a straight line L1. Translate the straight line L1 until it is tangent to the section of the skin, with the point of tangency being P4. Draw a perpendicular line L2 from P4 to L1, which intersects the straight line L1 at point P5. Translate the straight line L1 along the perpendicular line L2 in the opposite direction of the warping deformation of the stiffened panel at the section to form the straight line L1. ‘ It intersects the perpendicular line L2 at point P5. ‘ The endpoints on both sides of the skin become P2 ‘ P3 ‘ P5 and P5 ‘ The distance is D, and D = H max / R max +2(W1+W2) / W3, where H max W1 is the maximum thickness of the selected girder, W2 is the reference height of the selected girder's vertical reinforcement, W3 is the reference width of the bottom edge of the selected girder on one side, and W4 is the maximum distance between the selected girder and two adjacent girder units. Let P2 be the maximum thickness of the selected girder. ‘ P3 ‘ Based on P4, a new skin profile curve is constructed at the selected stringer axis.

[0011] 3. Following steps 1-2, construct new skin profile curves at all girder axes;

[0012] 4. Following steps 1-3, construct new skin surfaces based on the new skin profile curves at all stringer axes.

[0013] 5. Following steps 1-4, design the mold required for curing the stiffened wall panel based on the new skin surface.

[0014] Steps 1 and 2 through 5 can be performed in parallel.

[0015] To simplify the process, all stringers can use a uniform compensation angle for springback deformation. In this case, θ0 is the maximum theoretical included angle of all stringers in the stiffened panel, and R... max R is the maximum outer radius of all stringers in the reinforced wall panel.

[0016] To simplify the process, a uniform translation distance D can be used at all truss axis sections. In this case, H max W1 is the maximum thickness among all girder bars, W2 is the maximum vertical reinforcement reference height among all girder bars, W3 is the maximum single-sided bottom edge reference width among all girder bars, and W4 is the maximum distance between any two adjacent girder bars.

[0017] For I-shaped and J-shaped stringers, the compensation angle for the springback deformation of the non-bonded stringer mold is the average value of the compensation angle for the springback deformation of the bonded surface.

[0018] The complementary shaping method of the present invention has the following advantages: 1) It is simple and efficient, as the shaping compensation of the stringer and the skin only considers one direction, which greatly reduces the amount of calculation; 2) It adopts a "positive interactive compensation" strategy to suppress the springback deformation of the stringer in the vertical axis and the warping deformation of the stiffened wall panel in the stringer axis, respectively. The two are orthogonally coupled, which greatly reduces the solidification deformation of the stiffened wall panel and achieves twice the result with half the effort; 3) It can use unified parameters to further simplify the shaping process. Attached Figure Description

[0019] Figure 1 Schematic diagram of T-shaped stiffened wall panel

[0020] Figure 2 Schematic diagram of T-shaped truss

[0021] Figure 3 Schematic diagram of T-shaped stringer springback deformation

[0022] Figure 4 T-shaped long truss modification compensation diagram

[0023] Figure 5 Skin shaping compensation diagram

[0024] Figure 6 I-shaped reinforced wall panel schematic diagram

[0025] The numbers in the diagram are explained as follows: 1 - Skin, 2 - T-shaped girder, 3 - Non-aligned vertical stiffener surface, 4 - Non-bonded bottom edge surface, 5 - Intersection point P1, 6 - Outer radius of the girder, 7 - Non-bonded bottom edge surface after springback deformation, 8 - Non-bonded bottom edge surface after shape correction and compensation, 9 - End point P2 on one side of the skin, 10 - Straight line L1', 11 - Point P5, 12 - Straight line L1, 13 - End point P3 on one side of the skin, 14 - End point P2' on one side of the skin after compensation, 15 - End point P3' on one side of the skin after compensation, 16 - New profile curve, 17 - Vertical line L2, 18 - Point P4, 19 - Point P5', 20 - I-shaped girder. Detailed Implementation

[0026] The curing deformation of the stiffened panel is caused by the girder, the skin, and their coupling effect. Due to the complexity of the structure and the ply, the stiffened panel exhibits hyperbolic curing deformation, which affects its surface accuracy.

[0027] The industry generally uses process measures or mold modification compensation methods to suppress the curing deformation of stiffened panels.

[0028] The main process measures are to reduce the curing residual stress of the stiffened panel and the differences in curing residual stress between different regions by decreasing the heating and cooling rates and adjusting the layup structure, thereby mitigating curing deformation. However, narrowing the process window prolongs the high-temperature process of the composite material, reducing the overall performance of the stiffened panel. Adjusting the layup structure reduces the load-bearing efficiency of the stiffened panel and increases its weight. Furthermore, the effect of process measures in suppressing curing deformation of the stiffened panel is not significant.

[0029] The mold modification and compensation method involves replacing the theoretical surface with a non-theoretical surface in the mold design. After curing, the composite material part deforms from the non-theoretical surface to the theoretical surface, thereby improving the shape accuracy. The core of the mold modification and compensation method is the construction of the non-theoretical surface. For stiffened panels, common methods include compensating for the springback deformation of the stringer or compensating for the overall deformation of the stiffened panel.

[0030] The stiffened panel consists of stringers and skin, both of which undergo solidification deformation. Combined with coupling, this results in complex hyperbolic deformation. Therefore, simply suppressing the deformation of either the stringers or the skin has limited effectiveness. Furthermore, directly using the final solidified deformation as a benchmark involves an extremely cumbersome process of constructing a non-theoretical surface, and the accuracy is low.

[0031] This application employs a "positive-reciprocal compensation" strategy, adopting relatively independent shaping and compensation measures in the vertical girder axis and the girder axis (two orthogonal directions). In the vertical girder axis, the primary focus is on suppressing the springback deformation of the girder. In the girder axis, the primary focus is on suppressing the warping deformation of the stiffened panel. The shaping and compensation measures, each with its own emphasis in the two orthogonal directions, are coupled together to achieve the overall goal of suppressing the solidification deformation of the stiffened panel.

[0032] Both orthogonal directions use pre-estimated compensation parameters based on the structural characteristics of the workpiece, eliminating the need for manufacturing test specimens. To further simplify the process, both orthogonal directions can use their own unified parameters, resulting in a highly efficient implementation.

[0033] The present invention is as follows Figure 1 -6 is shown:

[0034] Example 1, T-shaped reinforced wall panel

[0035] This application uses a T-shaped stiffened wall panel as an example to present a complementary shaping method.

[0036] 1. In the thickest region of each girder 2, arbitrarily cut a cross-section along the girder axis. Extend the non-bonded bottom edge surface 4 towards the vertical reinforcement, and extend the non-aligned vertical reinforcement surface 3 towards the bottom edge. The two intersect at point P15, forming a theoretical angle θ0. With point P15 as the center, fix the non-aligned vertical reinforcement surface 3, and rotate the non-bonded bottom edge surface 4 in the opposite direction of the girder's springback deformation until it forms an angle θ1 with the non-aligned vertical reinforcement surface 3. The angle of rotation of the non-bonded bottom edge surface 4 is θ, i.e., θ = |θ0 - θ1|. Use θ as the compensation angle for the springback deformation of the girder's curing mold, θ = θ0 / T max +1 / R max , among which, T max R is the highest curing temperature. max This represents the maximum R value on the outer side of the stringer.

[0037] 2. Extend all the long girder 2 of the stiffened wall panel along the girder axis to both sides until they are the same length as the two ends of the skin 1. Select the longest girder after extension and cut the skin 1 of the stiffened wall panel along the girder axis. Connect the endpoints P29 and P313 on both sides of the skin at the section to form a straight line L112. Translate the straight line L112 until it is tangent to the section of the skin, with the point of tangency being P418. Draw a perpendicular line L217 from P418 to L112, which intersects the straight line L112 at point P511. Translate the straight line L112 along the perpendicular line L217 in the opposite direction of the warping deformation of the stiffened wall panel at the section to form a straight line L1'10, which intersects the perpendicular line L2 at point P5'19. The endpoints on both sides of the skin become P2'14 and P3'15. The distance between P511 and P5'19 is D, where D = H. max / R max +2(W1+W2) / W3, where H max W1 is the maximum thickness of the selected stringer, W2 is the reference height of the selected stringer reinforcement, W3 is the reference width of the bottom edge of the selected stringer on one side, and W4 is the maximum distance between the selected stringer and the two adjacent stringers. Based on P2'14, P3'15 and P418, a new skin profile curve is constructed at the axis of the selected stringer.

[0038] 3. Following step 2, construct new skin profile curves at all stringer axes.

[0039] 4. Following step 3, construct a new skin surface based on the new skin profile curves at all stringer axes.

[0040] 5. Following step 4, design the mold required for curing the stiffened wall panel based on the new skin surface.

[0041] Steps 1 and 2 through 5 can be performed in parallel.

[0042] Example 2, T-shaped reinforced wall panel

[0043] This application uses a T-shaped stiffened wall panel as an example to present a complementary shaping method.

[0044] 1. In the thickest region of each girder 2, arbitrarily cut a cross-section along the girder axis. Extend the non-bonded bottom edge surface 4 towards the vertical reinforcement, and extend the non-aligned vertical reinforcement surface 3 towards the bottom edge. The two intersect at point P15, forming a theoretical angle θ0. With point P15 as the center, fix the non-aligned vertical reinforcement surface 3, and rotate the non-bonded bottom edge surface 4 in the opposite direction of the girder's springback deformation until it forms an angle θ1 with the non-aligned vertical reinforcement surface 3. The angle of rotation of the non-bonded bottom edge surface 4 is θ, i.e., θ = |θ0 - θ1|. Use θ as the compensation angle for the springback deformation of the girder's curing mold, θ = θ0 / T max +1 / R max Where θ0 is the largest theoretical included angle among all the girder lengths of the stiffened wall panel, and T max R is the highest curing temperature. max The largest outer radius (R) of all the long stringers in the reinforced wall panel.

[0045] 2. Extend all the long girder 2 of the stiffened wall panel along the girder axis to both sides until they are the same length as the two ends of the skin 1. Select the longest girder after extension and cut the skin 1 of the stiffened wall panel along the girder axis. Connect the endpoints P29 and P313 on both sides of the skin at the section to form a straight line L112. Translate the straight line L112 until it is tangent to the section of the skin, with the point of tangency being P418. Draw a perpendicular line L217 from P418 to L112, which intersects the straight line L112 at point P511. Translate the straight line L112 along the perpendicular line L217 in the opposite direction of the warping deformation of the stiffened wall panel at the section to form a straight line L1'10, which intersects the perpendicular line L2 at point P5'19. The endpoints on both sides of the skin become P2'14 and P3'15. The distance between P511 and P5'19 is D, where D = H. max / R max +2(W1+W2) / W3, where H maxW1 is the maximum thickness among all stringers, W2 is the maximum height of the vertical reinforcement reference among all stringers, W3 is the maximum width of the bottom edge reference on one side among all stringers, and W3 is the maximum distance between any two adjacent stringers. Based on P2'14, P3'15 and P418, a new skin profile curve is constructed at the axis of the selected stringer.

[0046] 3. Following step 2, construct new skin profile curves at all stringer axes.

[0047] 4. Following step 3, construct a new skin surface based on the new skin profile curves at all stringer axes.

[0048] 5. Following step 4, design the mold required for curing the stiffened wall panel based on the new skin surface.

[0049] Steps 1 and 2 through 5 can be performed in parallel.

[0050] Example 3, I-shaped reinforced wall panel

[0051] This application takes an I-shaped reinforced wall panel as an example to propose a complementary modification method.

[0052] 1. In the thickest region of each girder 20, arbitrarily cut a section along the girder axis. Extend the non-bonded bottom edge surface 4 towards the vertical reinforcement, and extend the non-aligned vertical reinforcement surface 3 towards the bottom edge. The two intersect at point P15, forming a theoretical angle θ0. With point P15 as the center, fix the non-aligned vertical reinforcement surface 3, and rotate the non-bonded bottom edge surface 4 in the opposite direction of the girder's springback deformation until it forms an angle θ1 with the non-aligned vertical reinforcement surface 3. The angle of rotation of the non-bonded bottom edge surface 4 is θ, i.e., θ = |θ0 - θ1|. Use θ as the compensation angle for the springback deformation of the girder's curing mold, θ = θ0 / T max +1 / R max , among which, T max R is the highest curing temperature. max This represents the maximum R value on the outer side of the stringer.

[0053] 2. For the non-bonded surface of the I-beam, the compensation angle for the springback deformation of the cured mold is the average value of the compensation angle for the springback deformation of the bonded surface, i.e., θ = (θ 左 +θ 右 ) / 2, where θ 左 θ is the compensation angle for the springback deformation of the curing mold on the left side of the adhesive surface. 右 This is the compensation angle for the springback deformation of the curing mold on the right side of the adhesive surface.

[0054] 3. Extend all the long girder 20 of the stiffened wall panel to both sides along the girder axis until they are the same length as the two ends of the skin 1. Select the longest girder after extension and cut the skin 1 of the stiffened wall panel along the girder axis. Connect the endpoints P29 and P313 on both sides of the skin at the section to form a straight line L112. Translate the straight line L112 until it is tangent to the section of the skin, with the point of tangency being P418. Draw a perpendicular line L217 from P418 to L112, which intersects the straight line L112 at point P511. Translate the straight line L112 along the perpendicular line L217 in the opposite direction of the warping deformation of the stiffened wall panel at the section to form a straight line L1'10, which intersects the perpendicular line L2 at point P5'19. The endpoints on both sides of the skin become P2'14 and P3'15. The distance between P511 and P5'19 is D, where D = H. max / R max +2(W1+W2) / W3, where H max W1 is the maximum thickness of the selected stringer, W2 is the reference height of the selected stringer reinforcement, W3 is the reference width of the bottom edge of the selected stringer on one side, and W4 is the maximum distance between the selected stringer and the two adjacent stringers. Based on P2'14, P3'15 and P418, a new skin profile curve is constructed at the axis of the selected stringer.

[0055] 4. Following step 2, construct new skin profile curves at all stringer axes.

[0056] 5. Following step 3, construct a new skin surface based on the new skin profile curves at all stringer axes.

[0057] 6. Following step 4, design the mold required for curing the stiffened wall panel based on the new skin surface.

[0058] Steps 1 and 2 through 5 can be performed in parallel.

[0059] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. It should be noted that any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A complementary modification method, characterized in that... The modified profiles of the stringers and skin are perpendicular to each other, including the following steps: 1-1 In the thickest region of each girder, arbitrarily cut a section along the girder axis. Extend the non-bonded bottom edge towards the vertical reinforcement, and extend the non-aligned vertical reinforcement towards the bottom edge. The two intersect at point P1, forming a theoretical angle θ0. With point P1 as the center, fix the non-aligned vertical reinforcement surface and rotate the non-bonded bottom edge surface in the opposite direction of the girder's springback deformation until it forms an angle θ1 with the non-aligned vertical reinforcement surface. The angle of rotation of the non-bonded bottom edge surface is θ, i.e., θ = |θ0 - θ1|. Use θ as the compensation angle for the springback deformation of the girder's curing mold, θ = θ0 / T max +1 / R max , among which, T max R is the highest curing temperature. max The maximum R value on the outer side of the stringer; 1-2 Extend all the long girder of the stiffened panel along the girder axis to both sides until they are the same length as the two ends of the skin. Select the longest girder after extension, and cut the skin of the stiffened panel with the girder axis of this girder. Connect the endpoints P2 and P3 on both sides of the skin at the section to form a straight line L1. Translate the straight line L1 until it is tangent to the section of the skin, with the point of tangency being P4. Draw a perpendicular line L2 from P4 to L1, which intersects the straight line L1 at point P5. Translate the straight line L1 along the perpendicular line L2 in the opposite direction of the warping deformation of the stiffened panel at the section to form the straight line L1. ‘ It intersects the perpendicular line L2 at point P5. ‘ The endpoints on both sides of the skin become P2 ‘ P3 ‘ P5 and P5 ‘ The distance is D, and D = H max / R max +2(W1+W2) / W3, where H max W1 is the maximum thickness of the selected girder, W2 is the reference height of the selected girder's vertical reinforcement, W3 is the reference width of the bottom edge of the selected girder on one side, and W4 is the maximum distance between the selected girder and two adjacent girder units. Let P2 be the maximum thickness of the selected girder. ‘ P3 ‘ Based on P4, a new skin profile curve is constructed at the selected stringer axis. 1-3 Following steps 1-2, construct new skin profile curves at all stringer axes; 1-4 Following steps 1-3, construct new skin surfaces based on the new skin profile curves at all stringer axes; 1-5 Following steps 1-4, design the mold required for curing the stiffened wall panel based on the new skin surface.

2. The complementary modification method according to claim 1, characterized in that... Steps 1-1 and 1-2 to 1-5 can be performed in parallel.

3. The complementary modification method according to claim 1, characterized in that... To simplify the process, all stringers can use a uniform compensation angle for springback deformation. In this case, θ0 is the maximum theoretical included angle of all stringers in the stiffened panel, and R... max R is the maximum outer radius of all stringers in the reinforced wall panel.

4. The complementary modification method according to claim 1, characterized in that... To simplify the process, a uniform translation distance D can be used at all truss axis sections. In this case, H max W1 is the maximum thickness among all girder bars, W2 is the maximum vertical reinforcement reference height among all girder bars, W3 is the maximum single-sided bottom edge reference width among all girder bars, and W4 is the maximum distance between any two adjacent girder bars.

5. The complementary modification method according to claim 1, characterized in that... For I-shaped and J-shaped stringers, the compensation angle for the springback deformation of the non-bonded stringer mold is the average value of the compensation angle for the springback deformation of the bonded surface.

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