An aircraft skin assembly deformation suppression method based on stress field regulation

Abstract

The application provides an aircraft skin assembly deformation inhibition method based on stress field regulation, and belongs to the technical field of aircraft assembly. The method comprises the following steps: collecting skin parameters and riveting parameters, and setting a trigger condition; for the skin meeting the trigger condition, a three-dimensional stress displacement field model is established based on the thin plate theory, and a non-riveting area displacement field distribution diagram and a stress gradient distribution diagram are obtained through simulation calculation; a high-risk area determination model is established, and a high-risk area prone to deformation is demarcated according to the stress gradient through simulation calculation; a tape laying scheme is determined and the tape is laid in the high-risk area; the skin is subjected to riveting operation, and the real-time pretension is monitored, the real-time pretension is divided into intervals, and corresponding adjustment measures are taken according to the real-time pretension, and the riveting operation is continued and the skin assembly is completed. By using the method, the deformation of the non-riveting area of the skin can be controlled within a very small range, and the high-precision requirement of the aircraft assembly is met.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of aircraft assembly and relates to a method for inhibiting deformation of aircraft skin assembly based on stress field regulation. BACKGROUND

[0002] In existing aircraft skin assembly, the control method for deformation of non-connection area after riveting mainly includes:

[0003] (1) Traditional process compensation method: temporary counterweight or local heating is added in the deformation area through artificial experience, but there are problems such as low efficiency (single piece time consumption ≥ 2h), unstable effect (bulge height fluctuation exceeds ±0.5mm) and the like.

[0004] (2) Structural reinforcement method: the invention patent with publication number US20180105221A1 proposes to control deformation by increasing reinforcing rivets, which can reduce 15%-20% deformation, but leads to structural weight increase (about 3.5kg / m 2 ) and stress concentration.

[0005] (3) Active control method: the invention patent with publication number EP3561081B1 uses piezoelectric actuators to apply reverse deformation, but needs a complex control system (cost increase of 12000 dollars per station) and has high temperature sensitivity (efficiency decreases by 40% at 80℃).

[0006] Most of the existing process optimization methods are based on experience and trial and error, lack comprehensive and in-depth analysis of the stress field inside the skin, and cannot accurately predict the specific position and degree of bulge or depression of the skin in the non-riveting area under different riveting parameters and skin structure combinations. This makes the preventive measures lack of pertinence and difficult to fundamentally solve the deformation problem. The main problems include:

[0007] (1) Lack of quantitative analysis of skin stress field, intervention measures are disconnected from the mechanical mechanism;

[0008] (2) The stiffness matching problem has not been solved, and the additional structure easily causes secondary stress concentration;

[0009] (3) The control precision is insufficient (angle deviation > 30°, tension fluctuation > 20%). SUMMARY

[0010] In order to solve the above problems existing in the prior art, the application provides a kind of aircraft skin assembly deformation inhibition method based on stress field regulation. According to the skin material, trigger condition and corresponding critical stress gradient value are determined, when the trigger condition is met, three-dimensional stress displacement field modeling is triggered, when the adjacent stress gradient value is exceeded, it is determined as a high-risk area, the skin deformation amplitude is calculated to determine the adhesive tape laying scheme and lay adhesive tape, the pre-tension during riveting is monitored in real time, and secondary stacking can be carried out when the limit is exceeded. By using the method of the application, the deformation of the non-riveting area of the skin can be controlled within a very small range, meeting the high-precision requirements of aircraft assembly.

[0011] The technical scheme of the application is as follows:

[0012] A kind of aircraft skin assembly deformation inhibition method based on stress field regulation, comprising: collecting related parameters of skin to be assembled and riveting parameters, and setting trigger condition;For the skin that meets the trigger condition, a three-dimensional stress displacement field model is established based on the thin plate theory, and the non-riveting area displacement field distribution map and stress gradient distribution map are obtained by simulation calculation;A high-risk area determination model is established, and the high-risk area prone to deformation is divided according to the stress gradient by simulation calculation;The adhesive tape laying scheme is determined and laid in the high-risk area;Riveting operation is carried out on the skin, and real-time pre-tension is monitored, real-time pre-tension interval is divided, and corresponding adjustment measures are taken according to real-time pre-tension, riveting operation is continued and skin assembly is completed. Specifically, the steps include:

[0013] Step 1, data collection:

[0014] The material properties, skin thickness h and riveting parameters of the skin to be assembled are collected, wherein the material properties of the skin include elastic modulus E and Poisson's ratio v (the ratio of skin transverse shrinkage to longitudinal stretching), and the riveting parameters include riveting pitch and riveting force of various fasteners required by the skin to be assembled.

[0015] Step 2, determine trigger condition:

[0016] The trigger condition is set according to the historical experience data of various skins, including riveting pitch trigger value and skin thickness trigger value, and the corresponding trigger condition is selected according to the type of skin to be assembled. If the riveting pitch of the skin to be assembled is greater than the riveting pitch trigger value or the skin thickness is less than the skin thickness trigger value, it is determined that the trigger condition is met, and step 3 is executed. For the skin that does not meet the trigger condition, the riveting assembly process is directly entered, and the riveting assembly operation is completed.

[0017] Step 3, establish three-dimensional stress displacement field model and perform simulation:

[0018] In the aircraft coordinate system (i.e. the aircraft heading as the X-axis, the wing span as the Y-axis, and the X-Y plane normal as the Z-axis to establish the coordinate system), the three-dimensional stress displacement field control equation is established based on the thin plate theory as formula (1) (fourth-order partial differential equation), and the three-dimensional stress displacement field model is established based on the three-dimensional stress displacement field control equation to describe the deformation of the skin under the action of riveting force and internal stress:

[0019]

[0020] In the formula, D is the stiffness of the skin, that is, the ability of the skin itself to resist bending deformation, which is calculated according to ; w is the deflection function, that is, the vertical displacement of the skin at any position (x, y) under the action of load; q(x, y) is the transverse load at position (x, y), that is, the distributed force acting on the surface of the skin and perpendicular to the surface of the skin to drive the deformation; N x is the normal stress in the X direction; N y is the normal stress in the Y direction; N xy is the shear stress in the X-Y plane; and respectively represent the curvature change of the X direction and the Y direction of the skin caused by the load, and the positive curvature represents the skin protrusion, and the negative curvature represents the skin depression; and respectively represent the correction of the skin stiffness by the in-plane stress, and the in-plane stress includes N x and N y .

[0021] In formula (1), the left side of the equation represents the inhibition ability of the skin stiffness to the deformation, and the right side of the equation represents the external factors driving the deformation of the skin, including the transverse load and the in-plane stress, both of which together determine the final deformation and stress distribution of the skin, so formula (1) reflects the dynamic balance between the skin stiffness and the external load.

[0022] The boundary conditions of the three-dimensional stress displacement field model are set, specifically: ① the skin thickness is less than the skin thickness trigger value, ② the riveting interval is greater than or equal to the riveting interval trigger value, ③ the riveting force range boundary is set according to the skin type, and the riveting force of each fastener collected in step 1 needs to be within the riveting force range boundary. When any of the above conditions is not met, the three-dimensional stress displacement field model is invalid. When conditions ① or ② are not met, it means that the skin to be assembled can directly enter the riveting assembly process. For the skin to be riveted that does not meet condition ③, the skin deformation inhibition cannot be realized by the method.

[0023] The three-dimensional stress displacement field model is simulated by a finite element analysis software, and formula (1) is solved to calculate the displacement (representing the deformation) and stress gradient of each position in the non-riveting area of the skin to be assembled, and the displacement field distribution diagram and the stress gradient distribution diagram of the non-riveting area are obtained.

[0024] Step 4, mark the high-risk area:

[0025] According to the skin material properties collected in step 1, select the critical stress gradient, which is determined according to historical experience values of different types of aircraft skin product attributes, wherein the stress gradient refers to the rate of change of stress with space, which is a key indicator for judging local deformation risk. Build a high-risk area judgment model for easy deformation:

[0026]

[0027] In the formula, σ x and σ y are the micro-directional stresses of any position (x, y) on the skin in the X and Y directions, respectively, σ x and N x have the following relationship: σ y and N y have the following relationship:

[0028] Through finite element analysis software to simulate the high-risk area judgment model, the area exceeding the critical stress gradient of the skin to be assembled in the stress gradient distribution map is marked as a high-risk area prone to deformation and marked as red.

[0029] Step 5, adhesive tape laying parameter design and adhesive tape laying:

[0030] According to formula (1), by adjusting the in-plane stress, the equivalent bending resistance of the skin can be dynamically adjusted, so that the skin shows stronger anti-deformation and anti-buckling performance under external load. The in-plane stress can be adjusted by laying adhesive tape on the skin surface, that is, by adjusting the pre-tightening force F pre to suppress skin deformation. This control method is not to increase the stiffness D of the skin itself, but to achieve deformation suppression through mechanical balance.

[0031] According to the simulation results in step 3, determine the range of required pre-tightening force F pre , and then determine the selection range of required adhesive tape pre-tension σ pre , select the appropriate type of adhesive tape within the range.

[0032] Use formula (3) to calculate the adhesive tape width b:

[0033]

[0034] Determine the adhesive tape laying direction according to the energy functional minimization principle:

[0035]

[0036] In the formula, θ is the laying angle, that is, the angle between the tape laying direction and the X-axis; τ xy This refers to the microscopic shear force in the XY plane.

[0037] Determine the tape laying plan based on the tape width and tape laying direction. Lay the tape in the high-risk area marked in step 4 according to the tape laying plan. The laying process is as follows: mark the adhesive position and direction of the tape on the surface of the skin to be assembled, and use manual laying or adhesive equipment to accurately lay the tape in the high-risk area.

[0038] Step 6, Real-time stress monitoring and graded control:

[0039] Strain gauges are arrayed and attached to adhesive tape laid in high-risk areas. During the riveting operation of the skin to be assembled, strain gauges are used to collect the skin displacement in real time during the riveting process, and σ is calculated based on the skin displacement. x σ y and τ xy Based on the principle of equivalent stress, the real-time pretension is calculated using formula (5).

[0040]

[0041] Divide the real-time pretensioning into graded intervals and take corresponding adjustment measures:

[0042] 1) such as The riveting operation continues in the current state until the skin assembly is completed, where σ yield This represents the yield strength of the skin material.

[0043] 2) such as Then pause the riveting operation and press [button / button]. Reselect σ pre For higher-value tape types, ΔT is the pretension adjustment amount; Kp is the proportional coefficient, which is empirical data; after removing the laid tape, σ pre Higher-value tape was laid in the high-risk area according to the original laying plan. After the tape was re-laid, the riveting operation continued, and the skin assembly was finally completed.

[0044] 3) such as If this happens, the riveting operation is paused. In the high-risk area, a second layer of tape is laid over the existing tape, following the direction of the principal stress, which is calculated using simulation in step 3. After the second layer of tape is laid, the riveting operation continues, ultimately completing the skin assembly.

[0045] The beneficial effects of this invention are as follows:

[0046] (1) Effectively suppress deformation: By accurately analyzing the three-dimensional stress displacement field before assembly and reasonably formulating and implementing the adhesive tape laying scheme, the invention can significantly reduce the probability of bulging or depression in the non-riveted area of the aircraft skin after rivet assembly. A large amount of experimental data and actual application cases show that after using the invention method, the deformation of the non-riveted area of the skin can be controlled within a very small range, meeting the high precision requirements of aircraft assembly.

[0047] (2) Improve assembly quality and efficiency: Since the invention can predict and prevent deformation problems in advance, it avoids a lot of rework and delays caused by traditional post-detection and repair. In actual production, it can reduce the adjustment and repair time in the assembly process, improve the overall assembly efficiency, and at the same time improve the assembly quality of the aircraft, ensuring the integrity and safety of the aircraft structure.

[0048] (3) Reduce costs: The invention reduces assembly rework and scrap caused by skin deformation, reducing material and labor costs. In addition, by optimizing the adhesive tape laying scheme and selecting the appropriate laying method, the material usage is reasonably controlled under the premise of ensuring the effect, further reducing the cost.

[0049] (4) Enhance adaptability and versatility: By adjusting the input parameters of the three-dimensional stress displacement field model and the parameters in the calculation formula related to the adhesive tape laying scheme, the invention can be applied to the skin assembly of large civil aircraft of different models and structures, and can provide personalized deformation suppression solutions for various complex assembly situations, with wide application prospects.

[0050] In summary, the invention triggers stress displacement field modeling from geometric and mechanical conditions, realizes adhesive tape laying scheme design and tension dynamic regulation, forms a complete closed loop, reduces the skin bulging height by 75%-82% (from typical deformation value 0.5-1.2mm to 0.03-0.05mm), improves stress uniformity: coefficient of variation from 0.38 to 0.12, greatly improves the efficiency and quality of aircraft assembly skin assembly riveting. BRIEF DESCRIPTION OF DRAWINGS

[0051] Figure 1 The flowchart of the invention scheme.

[0052] Figure 2 The displacement field distribution diagram of the non-riveted area, wherein (a) is the displacement field distribution diagram of the non-riveted area, and (b) is the rivet point position diagram.

[0053] Figure 3 High-risk identification area view. DETAILED DESCRIPTION

[0054] The technical solutions of the present application will be described clearly and completely below. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments of the present application, all other embodiments improved or adjusted by those skilled in the art belong to the protection scope of the present application.

[0055] The present application is described clearly and completely by taking the aluminum alloy skin of a certain type of aircraft as an example.

[0056] An aircraft skin assembly deformation inhibition method based on stress field regulation, as shown in the flowchart Figure 1 The method comprises the following steps.

[0057] Step 1: Data collection

[0058] The material properties, skin thickness h and riveting parameters of the aluminum alloy skin are collected, wherein the material properties of the skin include the elastic modulus E and the Poisson's ratio v, and the riveting parameters include the riveting spacing and the riveting force of various fasteners.

[0059] Step 2: Determine the trigger condition

[0060] The trigger condition is set according to the historical experience data of various skins. The aircraft skin is a thin plate type part. According to the historical test data of the aluminum alloy skin, when the riveting point spacing is greater than 50 mm or the skin thickness is less than 2 mm, the skin support stiffness will decrease by 40%, and deformation is prone to occur. The trigger condition is set as shown in Table 1:

[0061] Table 1: Trigger condition

[0062]

[0063] If the riveting spacing of the aluminum alloy skin is > 50 mm or the skin thickness is < 2 mm, it is determined that the trigger condition is met, and step 3 is performed. For the aluminum alloy skin that does not meet the trigger condition, it directly enters the riveting assembly process and completes the riveting assembly operation.

[0064] Step 3: Establish a three-dimensional stress displacement field model and perform simulation

[0065] A three-dimensional stress displacement field control equation is established based on the thin plate theory, as shown in equation (1).

[0066] In the aircraft coordinate system (i.e. the aircraft heading is taken as the X axis, the wing span is taken as the Y axis, and the X-Y plane normal is taken as the Z axis to establish the coordinate system), a three-dimensional stress displacement field control equation is established based on the thin plate theory, i.e. the thin plate equation as shown in equation (1). A three-dimensional stress displacement field model is established based on the three-dimensional stress displacement field control equation, which is used to describe the deformation of the skin under the action of riveting force and internal stress.

[0067] The left side of the equation in formula (1) represents the ability of the skin stiffness to inhibit deformation, and the right side of the equation represents external factors that drive the deformation of the skin, including transverse load and in-plane stress, which together determine the final deformation and stress distribution of the skin, so formula (1) embodies the dynamic balance between the stiffness of the skin and the external load.

[0068] The boundary conditions of the three-dimensional stress displacement field model are set, specifically: ① the skin thickness is less than 2 mm, ② the riveting interval is greater than 50 mm, ③ the lower boundary of the riveting force range of the aluminum alloy skin is set to 1.25 KN, and the upper boundary is set to 6.8 KN, and the riveting force of each fastener collected in step 1 needs to be greater than or equal to 1.25 KN and less than or equal to 6.8 KN; if any of the above conditions is not met, the three-dimensional stress displacement field model is invalid, if conditions ① or ② are not met, it means that the aluminum alloy skin can directly enter the riveting assembly process, and for the aluminum alloy skin that does not meet condition ③, the skin deformation cannot be inhibited by the method.

[0069] In order to simplify the three-dimensional stress displacement field model, in this embodiment, the skin curvature is ignored, the aluminum alloy skin is simplified as a flat plate, and the riveting state in the model is simplified as a symmetric riveting in a rectangular shape, that is, the riveting points in each riveting area are simplified as a rectangular distribution (such as Figure 2 (b) in the middle), then where A is the unit cross-sectional area, and A = h; since N x = N y , the shear forces in the X and Y directions cancel each other out, so N xy = 0, that is, no shear stress is generated in the X-Y plane.

[0070] The three-dimensional stress displacement field model is simulated by a finite element analysis software, and formula (1) is solved to calculate the displacement and stress gradient of each position in the non-riveting area of the aluminum alloy skin, and the displacement field distribution diagram (such as Figure 2 (a) in the middle) and the stress gradient distribution diagram are obtained.

[0071] Step 4, mark the high-risk area:

[0072] According to the material properties of the aluminum alloy skin collected in step 1, the critical stress gradient is selected, and the critical stress gradient is determined according to the historical experience value of different types of aircraft skin product properties. The critical stress gradient values of the aluminum alloy skin and the carbon fiber composite material skin are shown in Table 2. When the stress gradient of a certain area exceeds the critical stress gradient, it indicates that there is severe stress concentration in this area, which is easy to cause bulging or depression:

[0073] Table 2: Critical stress gradient

[0074] Material Type Critical Stress Gradient (MPa / mm) Aluminum Alloy 25 Carbon Fiber Composite 35

[0075] A high-risk area determination model for easy deformation is constructed as follows by using the critical stress gradient of the aluminum alloy skin:

[0076]

[0077] The high-risk area determination model is simulated by a finite element analysis software. The area exceeding the critical stress gradient of the aluminum alloy skin in the stress gradient distribution map is marked as a high-risk area for easy deformation and is marked in red, as shown in Figure 3 .

[0078] Step 5, adhesive tape laying parameter design and adhesive tape laying:

[0079] According to formula (1), the equivalent bending resistance of the skin can be dynamically adjusted by adjusting the in-plane stress, so that the skin exhibits stronger anti-deformation and anti-buckling performance under external load. The in-plane stress can be adjusted by laying adhesive tape on the skin surface, that is, by adjusting the pre-tightening force F pre exerted on the skin after laying the adhesive tape to suppress the deformation of the skin. This adjustment method does not increase the stiffness D of the skin itself, but achieves deformation suppression through mechanical balance.

[0080] According to the simulation results in step 3, the range of the required pre-tightening force F pre is determined, and the selection range of the required adhesive tape pre-tension σ pre is determined as σ pre ∈ [5, 15] MPa. In this range, an aluminum alloy platinum adhesive tape is selected.

[0081] The adhesive tape width b is calculated as 400 mm using formula (3).

[0082] According to the energy functional minimization principle, the laying angle θ is calculated using formula (4) to determine the adhesive tape laying direction. Since the riveting state in the three-dimensional stress displacement field model is simplified to a symmetric riveting in a rectangular shape, τ xy = 0, and the laying angle θ can be simplified to 45°.

[0083] The adhesive tape laying scheme is determined according to the adhesive tape width and the adhesive tape laying direction. The adhesive tape is accurately laid in the high-risk area determined in step 4 by marking the adhesive tape sticking position and direction on the surface of the aluminum alloy skin and using manual laying.

[0084] Step 6, real-time stress monitoring and hierarchical control:

[0085] The strain gauges are arrayed and stuck on the adhesive tape laid in the high-risk area. The displacement of the skin during the riveting operation is collected in real time by the strain gauges, with a sampling rate of 1 kHz. According to the displacement of the skin, σ x , σ y , and τxy According to the equivalent stress principle, the real-time pre-tension is calculated by formula (5)

[0086] The real-time pre-tension interval is divided, and the corresponding adjustment measures are taken:

[0087] 1) If The current state is maintained to continue the riveting operation, and the σ yield of the aluminum alloy skin is 325 MPa.

[0088] 2) If The riveting operation is suspended, and the σ is reselected, and the σ pre of the adhesive tape is higher, wherein the Kp of the aluminum alloy skin is generally selected as 0.4; the laid adhesive tape is removed, and the adhesive tape with higher σ pre is laid in the high-risk area according to the original laying scheme. After the adhesive tape is re-laid, the riveting operation is continued, and the skin assembly is finally completed.

[0089] 3) If The riveting operation is suspended, and the aluminum alloy adhesive tape is also used on the laid adhesive tape in the high-risk area, and the second layer of adhesive tape is laid along the principal stress direction, which is obtained by simulation and calculation in step 3. After the second layer of adhesive tape is laid, the riveting operation is continued, and the skin assembly is finally completed.

[0090] In this embodiment, the real-time pre-tension In interval 2), the adjustment measure of replacing the adhesive tape is adopted, and the laid aluminum alloy adhesive tape is replaced with a carbon fiber reinforced epoxy adhesive tape, which has higher elastic modulus and stronger inhibitory effect.

[0091] After the riveting process of the aluminum alloy skin is inhibited by the method of this embodiment, the surface waviness is checked, and the quality meets the tolerance requirement of 0.015 mm.

[0092] The above-described embodiments only express the implementation of the present application, but cannot be interpreted as a limitation on the scope of the present application. It should be noted that for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the scope of protection of the present application.

Claims

1. An aircraft skin assembly deformation suppression method based on stress field regulation, characterized in that, The method comprises the following steps: Collecting parameters related to the skin to be assembled and riveting parameters, and setting a triggering condition; For the skin meeting the triggering condition, a three-dimensional stress displacement field model is established based on the thin plate theory, and a non-riveting area displacement field distribution map and a stress gradient distribution map are obtained through simulation calculation; A high-risk area determination model is established, and the high-risk area prone to deformation is determined according to the stress gradient through simulation calculation; The adhesive tape laying scheme is determined and the adhesive tape is laid in the high-risk area; The riveting operation is performed on the skin, the real-time pre-tension is monitored, the real-time pre-tension classification interval is divided, and corresponding adjustment measures are taken according to the real-time pre-tension, the riveting operation is continued and the skin assembly is completed; In the aircraft coordinate system, a three-dimensional stress displacement field control equation is established based on the thin plate theory as formula (1), and a three-dimensional stress displacement field model is established based on the three-dimensional stress displacement field control equation; where D is the skin stiffness; w is the deflection function, i.e. the vertical displacement of the skin at any location (x, y) under load; q(x, y) is the transverse load at location (x, y); N x is the normal stress in the X direction; N y is the normal stress in the Y direction; N xy is the shear stress in the X-Y plane; and represent the change in curvature of the skin in the X and Y directions, respectively, caused by the load; and represent the modification of the skin stiffness by the in-plane stresses, which include N x and N y ; equation (1) embodies the dynamic balance between the skin stiffness and the external load; According to formula (1), the equivalent bending resistance of the skin can be dynamically adjusted by adjusting the in-plane stress, and the in-plane stress can be adjusted by laying adhesive tape on the surface of the skin, i.e. by adjusting the pre-tightening force F applied to the skin after laying the adhesive tape pre suppressing deformation of the skin; According to the displacement field distribution map and the stress gradient distribution map of the non-riveting area, the required pre-tightening force F is determined pre , and the selection range of the required adhesive tape pre-tension σ pre is determined, the applicable adhesive tape type is selected in the range, the adhesive tape width and the adhesive tape laying direction are calculated to determine the adhesive tape laying scheme, and the adhesive tape is laid in the high-risk area according to the adhesive tape laying scheme. During the riveting operation on the skin to be assembled, the displacement of the skin is collected in real time by using a strain gauge, and the real-time pretension is calculated according to the equivalent stress principle The real-time pre-tension classification interval is divided, and corresponding adjustment measures are taken: 1) as The riveting operation is continued until the completion of the skin assembly, where σ yield represents the yield strength of the skin material; 2) as the riveting operation is suspended, σ pre is higher; the already laid adhesive tape is removed and the adhesive tape with a higher σ pre value is laid in the high-risk area according to the original laying plan; the riveting operation is continued and the skin assembly is finally completed; 3) as If the result is not satisfied, riveting operation is suspended, and the second layer of adhesive tape is laid along the principal stress direction in the high-risk area, which is calculated by the simulation in step 3; the riveting operation is continued, and the skin assembly is finally completed.

2. The method of claim 1, wherein, Specifically, the method comprises the following steps: Step 1, data collection: Collect the material properties, skin thickness h and riveting parameters of the skin to be assembled, wherein the material properties of the skin include the elastic modulus E and the Poisson's ratio v, and the riveting parameters include the riveting pitch and the riveting force of various fasteners required by the skin to be assembled; Step 2, determine the triggering condition: Set the triggering condition, which includes the riveting pitch triggering value and the skin thickness triggering value. If the riveting pitch of the skin to be assembled is greater than the riveting pitch triggering value or the skin thickness is less than the skin thickness triggering value, it is determined that the triggering condition is met, and step 3 is executed; if the triggering condition is not met, the riveting assembly process is directly entered, and the riveting assembly operation is completed; Step 3, establish a three-dimensional stress displacement field model and perform simulation: Set the boundary conditions of the three-dimensional stress displacement field model; simulate the three-dimensional stress displacement field model, and solve formula (1) to calculate the displacement and stress gradient of each position in the non-riveting area of the skin to be assembled, and obtain the non-riveting area displacement field distribution map and the stress gradient distribution map; Step 4, mark the high-risk area: Determine the critical stress gradient, and construct a high-risk area determination model prone to deformation: where σx and σy are the microscopic directional stresses in the X and Y directions, respectively, at any location (x, y) on the skin. x and σy y are the microscopic directional stresses in the X and Y directions, respectively, at any location (x, y) on the skin. Simulate the high-risk area determination model, and mark the area in the stress gradient distribution map that exceeds the critical stress gradient of the skin to be assembled as the high-risk area prone to deformation; Step 5, adhesive tape laying parameter design and adhesive tape laying; Step 6, real-time stress monitoring and classification control.

3. The method of claim 2, wherein, The skin stiffness is calculated according to Step 3.

4. The method of claim 2, wherein, In step 3, the boundary conditions of the three-dimensional stress displacement field model include: ① the skin thickness is less than the skin thickness triggering value, ② the riveting pitch is greater than the riveting pitch triggering value, ③ the riveting force range boundary is set according to the skin type, and the riveting force of each fastener collected in step 1 needs to be within the riveting force range boundary; when any of the above conditions is not met, the three-dimensional stress displacement field model is invalid.

5. The method of claim 2, wherein, The relationship between σ x and N x is: The relationship between σ y and N y is:

6. The method of claim 2, wherein, In step 5, the adhesive tape width b is calculated using formula (3): The adhesive tape laying direction is determined according to the energy functional minimization principle: In the formula, θ is a laying angle, that is, an included angle between the laying direction of the adhesive tape and the X axis, τ xy is a micro-shear force in the X-Y plane.

7. The method of claim 2, wherein, In step 5, the adhesive tape laying process is as follows: mark the adhesive tape sticking position and direction on the surface of the skin to be assembled, and lay the adhesive tape in the high-risk area by manual laying or sticking equipment.

8. The method of claim 2, wherein, In step 6, the strain gauge calculates σ x , σ y and τ xy using the displacement of the skin collected in real time, and then calculates the real-time pretension force using formula (5) 9. The method of claim 2, wherein, In step 6, according to reselect σ pre the adhesive tape type with a higher value, where ΔT is a pretension adjustment amount and Kp is a proportional coefficient.

10. The method of claim 2, wherein, The three-dimensional stress displacement field model can simplify the skin into a flat plate ignoring the skin curvature, and simplify the riveting state into a symmetric riveting of rectangular shape, so that N x = N y , that is, the shear forces in the X direction and the Y direction cancel each other out, so that N xy = 0, that is, no shear stress is generated in the X-Y plane.

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