Stress boundary determination method for large wing assembly tooling flag

Abstract

The invention discloses a tool flag stress boundary determination method for large wing assembly, which comprises the following steps of: 1, establishing a tool flag three-dimensional geometric model in a large wing assembly tool, performing simplification processing to obtain a tool flag simplified model, and determining a wing model mass center point in the simplified model; 2, mechanical boundary conditions are set for the simplified tool flag model; step 3, establishing a constraint equation according to the simplified tool flag model and the centroid point of the wing model; 4, applying a concentrated load to the centroid point of the wing model of the simplified tooling flag model to solve the displacement field and stress field results of the simplified tooling flag model under the concentrated load so as to judge whether the design rigidity of the simplified tooling flag model meets the requirement or not; and step 5, solving a stress field result of the tool flag simplification model under concentrated load for the tool flag simplification model meeting the rigidity design requirement obtained in the step 4, and calculating a stress boundary of each tool flag in the tool flag simplification model. According to the technical scheme provided by the embodiment of the invention, the problems that the stress of the designed tooling flags is inaccurate, the distribution positions and quantity of the tooling flags obtained based on the stress are unreasonable, and the working efficiency is low due to the fact that a traditional design mode aiming at the stress boundary of the tooling flags does not consider a real space distribution form of the tooling flags and has a large difference from an actual situation are solved. Therefore, the problem that the whole wing tool deforms due to the fact that the local tool flag is stressed greatly is solved.

Description

Technical Field

[0001] The invention relates to the field of wing assembly technology, but is not limited to it, and in particular to a method for determining a force boundary of a large wing assembly tooling flag. Background Art

[0002] During the assembly of large wings, the tooling flags on the assembly tooling directly affect the positioning accuracy and efficiency. In order to prevent the assembly accuracy from decreasing due to the deformation of the tooling flag structure during the use of the tooling, it is necessary to calculate the force of each tooling flag, that is, to determine its force boundary. In this way, the distribution position and number of tooling flags can be evaluated to avoid the deformation of the entire wing tooling due to the unreasonable design position and number of tooling flags, which may cause the local tooling flags to be subjected to large forces.

[0003] The traditional design method for the stress boundary of the tooling flag is to obtain the stress boundary of each tooling flag by averaging the wing weight divided by the number of tooling flags. The actual spatial distribution of the tooling flags is not taken into account, which is quite different from the actual situation. As a result, the designed tooling flag stress is inaccurate, and the distribution position and number of the tooling flags obtained based on this are unreasonable. Summary of the invention

[0004] Purpose of the present invention: In order to solve the above-mentioned technical problems, an embodiment of the present invention provides a method for determining the force boundary of a tooling flag for large-scale wing assembly, so as to solve the problem that the traditional design method for the force boundary of the tooling flag does not take into account the actual spatial distribution form of the tooling flag, which is quite different from the actual situation, resulting in inaccurate force on the designed tooling flag, and the tooling flag distribution position and quantity obtained based on this are unreasonable, which in turn causes the local tooling flag to be subjected to large force, causing the deformation of the entire wing tooling.

[0005] Technical solution of the present invention: In a first aspect, an embodiment of the present invention provides a method for determining a force boundary of a tooling flag for assembling a large wing, comprising:

[0006] Step 1: Establish a three-dimensional geometric model of the tooling flag in the large-scale wing assembly tooling, obtain a simplified model of the tooling flag through simplification, and determine the centroid of the wing model in the simplified model;

[0007] Step 2, setting mechanical boundary conditions for the simplified model of the tooling flag;

[0008] Step 3, establishing constraint equations based on the simplified model of the tooling flag and the centroid of the wing model;

[0009] Step 4: by applying a concentrated load at the centroid of the wing model of the simplified model of the tooling flag, the displacement field and stress field results of the simplified model of the tooling flag under the concentrated load are solved to determine whether the design stiffness of the simplified model of the tooling flag meets the requirements;

[0010] Step 5: For the simplified model of the tooling flag obtained in step 4 that meets the stiffness design requirements, solve the stress field results of the simplified model of the tooling flag under the concentrated load, and calculate the force boundary of each tooling flag in the simplified model of the tooling flag.

[0011] Optionally, in the above-mentioned method for determining the force boundary of a tooling flag for assembling a large wing, the step 1 comprises:

[0012] Step 1-1, using CAD software to establish a three-dimensional geometric model of a tooling flag in a large wing assembly, and in the three-dimensional geometric model of the tooling flag, by deleting all parts except the wing tooling flag 1, bolt hole 2, and tooling flag rib 3 in each tooling flag model, a simplified model of the tooling flag is formed;

[0013] Step 1-2, set the center of mass point of the wing model in the simplified model of the tooling flag, and use the center of mass point to replace the entire wing model. The spatial coordinates of the center of mass point are consistent with the center of gravity of the wing model.

[0014] Optionally, in the above-mentioned method for determining the force boundary of a tooling flag for large wing assembly, the simplified model of the tooling flag obtained in step 1-1 has the following requirements:

[0015] The simplified model of the tooling flag is required to be the same as the length, width and height of each tooling flag in the actual wing assembly, and the distribution position, size, bolt hole position and bolt hole radius of each tooling flag in the simplified model are required to be consistent with those of each tooling flag in the wing assembly.

[0016] Optionally, in the above-mentioned method for determining the force boundary of a tooling flag for assembling a large wing, the step 2 comprises:

[0017] Step 2-1, according to the material type of the tooling flag, set the Young's modulus, Poisson's ratio, and material density of the tooling flag;

[0018] Step 2-2, setting 6-DOF constraints at the bolt hole positions of each tooling flag in the simplified tooling flag model as mechanical boundary conditions of the simplified tooling flag model.

[0019] Optionally, in the above-mentioned method for determining the force boundary of a tooling flag for assembling a large wing, the step three comprises:

[0020] Based on the position of the centroid of the wing model in the simplified model of the tooling flag, the constraint equations for the centroid of the wing model and the upper surface of the tooling flag are established as follows:

[0021]

[0022] Among them, u1, u2, and u3 represent the three displacement components of the wing heading, span direction, and gravity direction respectively; the superscripts F and w represent the tooling flag and the center of mass of the wing model respectively.

[0023] Optionally, in the above-mentioned method for determining the force boundary of a tooling flag for assembling a large wing, the step 4 comprises:

[0024] Step 4-1, dividing the simplified model of the tooling flag into grid units, wherein the maximum length, width and height of the grid units in the simplified model of the tooling flag shall not exceed 10% of the length, width and height of the tooling flag;

[0025] Step 4-2, in the finite element software, according to the design results of the wing model, a concentrated load is applied to the center of mass of the wing model, and the static solution method is used to calculate the displacement field and stress field results of the simplified model of the tooling flag under the concentrated load; and the maximum values ​​of the three displacement components u of the simplified model of the tooling flag in the heading direction, span direction, and gravity direction are obtained. 1,max 、u 2,max 、u 3,max ;

[0026] Step 4-3: Set the maximum values ​​of the three displacement components u of the simplified model of the tooling flag 1,max 、u 2,max 、u 3,max Compare with the design allowable values ​​[u1], [u2], [u3] to determine whether the design stiffness of the simplified model of the tooling flag meets the requirements.

[0027] Optionally, in the above-mentioned method for determining the force boundary of the tooling flag for large wing assembly, the method for judging whether the design stiffness of the simplified model of the tooling flag meets the requirements in step 4-3 is:

[0028] When the maximum values ​​of the three displacement components of the simplified model of the tooling flag are all less than the design allowable values, it is judged that the stiffness design of the simplified model of the tooling flag meets the requirements;

[0029] When the maximum value of at least one displacement component of the simplified model of the tooling flag is greater than or equal to the corresponding design allowable value, it is determined that the deformation of the simplified model of the tooling flag is out of tolerance; the following processing is performed:

[0030] By increasing the number of tooling flags in the current simplified tooling flag model, or increasing the thickness or height of the tooling flags, or changing the distribution position of the tooling flags; repeating steps 4-1 to 4-3 until the maximum values ​​of the three displacement components of the simplified tooling flag model are calculated to be less than the design allowable values, the simplified tooling flag model is used as a model for determining the force boundary.

[0031] Optionally, in the above-mentioned method for determining the force boundary of a tooling flag for assembling a large wing, the step five comprises:

[0032] Step 5-1, based on the stress field results of the simplified model of the tooling flag that meets the stiffness design requirements under concentrated load, integrate the contact stress to obtain the support reaction force F of a single tooling flag in the simplified model of the tooling flag in the heading, span, and gravity directions. x 、F y 、F z :

[0033]

[0034] Among them, σ 11 , σ 22 , σ 33 is the stress component of one of the grid cells along the x, y, and z directions, and A is the inner surface area of ​​the bolt hole of the tooling flag;

[0035] Step 5-2, repeat step 5-1, and calculate the support reaction force F of each tooling flag in the heading direction, span direction, and gravity direction in turn. x 、F y 、F z , that is, to obtain the force boundary of the tooling flag in the large wing assembly.

[0036] In a second aspect, an embodiment of the present invention further provides a computer-readable storage medium, including: a memory and a processor;

[0037] Wherein, the memory is used to store a computer-readable program;

[0038] The processor is used to implement the method for determining the force boundary of the tooling flag for large wing assembly as described in any one of the above items when executing the computer-readable program.

[0039] Beneficial effects of the present invention: The embodiment of the present invention provides a method for determining the force boundary of a tooling flag for large-scale wing assembly. Specifically, it is a method for calculating the force magnitude of each tooling flag in the wing assembly tooling, thereby evaluating the distribution position and quantity of the tooling flags. The technical solution provided by the embodiment of the present invention calculates the force state of each tooling flag in the wing assembly tooling by considering factors such as the geometric form of the tooling flag, the material type, the deadweight of the tooling flag, and the force and moment balance, and obtains the force boundary of all tooling flags; based on the calculated force boundary, on the one hand, it can be evaluated whether the number, geometric size, and structural form of the tooling flag can meet the deformation requirements of each stage of the assembly process; on the other hand, according to the force boundary, the position, quantity, and material of the tooling flag can be optimized and designed, and the rigidity of the large-scale wing tooling flag structure can be further improved, and the phenomenon of precision reduction caused by tooling precision deformation due to insufficient tooling flag rigidity can be prevented. The method for determining the force boundary of the tooling flag provided by the present invention is a fast and effective calculation method. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The accompanying drawings are used to provide a further understanding of the technical solution of the present invention and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present invention and do not constitute a limitation on the technical solution of the present invention.

[0041] Figure 1 A flow chart of a method for determining a force boundary of a large wing assembly tooling flag proposed by the present invention;

[0042] Figure 2 A schematic diagram of a finite element model of a wing assembly tooling flag and a wing product centroid in a method for determining a force boundary provided in an embodiment of the present invention;

[0043] Figure 3 A schematic diagram of a mesh unit model of a finite element in a method for determining a force boundary provided in an embodiment of the present invention;

[0044] Figure 4 A schematic diagram of a stress field result calculated in a method for determining a force-bearing boundary provided in an embodiment of the present invention;

[0045] Figure 5 A schematic diagram of the heading direction, span direction, and support reaction force along the gravity direction of each tooling flag calculated in the force boundary determination method provided in an embodiment of the present invention.

[0046] Description of reference numerals:

[0047] 1. Tooling flag; 2. Bolt hole; 3. Tooling flag rib; 4. Tooling flag end face; 5. Centroid of wing product; 6. Grid unit. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solution and advantages of the present invention more clear, the embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other arbitrarily without conflict.

[0049] The above background technology has explained the important role of each tooling flag in the assembly process of large wings, and the necessity of determining the force boundary of each tooling flag. However, the traditional design method for the force boundary of the tooling flag does not take into account the actual spatial distribution of the tooling flag, which is quite different from the actual situation, resulting in inaccurate force of the designed tooling flag, and the distribution position and number of the tooling flag obtained based on this are unreasonable.

[0050] In view of the above problems, an embodiment of the present invention proposes a method for determining the force boundary of tooling flags for large wing assembly, by calculating the force magnitude of each tooling flag in the wing assembly tooling, and evaluating the distribution position and quantity of the tooling flags.

[0051] The present invention provides the following specific embodiments which can be combined with each other. The same or similar concepts or processes may not be described in detail in some embodiments.

[0052] Figure 1 The flow chart of a method for determining the force boundary of a large wing assembly tooling flag proposed by the present invention. The method for determining the force boundary of a large wing assembly tooling flag provided by an embodiment of the present invention comprises the following steps:

[0053] Step 1: Establish a three-dimensional geometric model of the tooling flag in the large-scale wing assembly tooling, obtain a simplified model of the tooling flag through simplification, and determine the centroid of the wing model in the simplified model;

[0054] Step 2, setting mechanical boundary conditions for the simplified model of the tooling flag;

[0055] Step 3, establishing constraint equations based on the simplified model of the tooling flag and the centroid of the wing model;

[0056] Step 4: by applying a concentrated load at the centroid of the wing model of the simplified model of the tooling flag, the displacement field and stress field results of the simplified model of the tooling flag under the concentrated load are solved to determine whether the design stiffness of the simplified model of the tooling flag meets the requirements;

[0057] Step 5: For the simplified model of the tooling flag obtained in step 4 that meets the stiffness design requirements, solve the stress field results of the simplified model of the tooling flag under the concentrated load, and calculate the force boundary of each tooling flag in the simplified model of the tooling flag.

[0058] In one implementation of the embodiment of the present invention, the implementation process of the above step 1 may include:

[0059] Step 1-1, using CAD software to establish a three-dimensional geometric model of a tooling flag in a large wing assembly, and in the three-dimensional geometric model of the tooling flag, by deleting all parts except the wing tooling flag 1, bolt hole 2, and tooling flag rib 3 in each tooling flag model, a simplified model of the tooling flag is formed;

[0060] Step 1-2, set the center of mass point of the wing model in the simplified model of the tooling flag, and use the center of mass point to replace the entire wing model. The spatial coordinates of the center of mass point are consistent with the center of gravity of the wing model.

[0061] In the specific implementation of this implementation, the simplified model of the tooling flag is obtained in step 1-1, which has the following requirements:

[0062] The simplified model of the tooling flag is required to be the same as the length, width and height of each tooling flag in the actual wing assembly, and the distribution position, size, bolt hole position and bolt hole radius of each tooling flag in the simplified model are required to be consistent with those of each tooling flag in the wing assembly.

[0063] In one implementation of the embodiment of the present invention, the implementation process of the above step 2 may include:

[0064] Step 2-1, according to the material type of the tooling flag, set the Young's modulus, Poisson's ratio, and material density of the actual tooling flag;

[0065] Step 2-2, setting 6-DOF constraints at the bolt hole positions of each tooling flag in the simplified tooling flag model as mechanical boundary conditions of the simplified tooling flag model.

[0066] In one implementation of the embodiment of the present invention, the implementation process of the above step three may include:

[0067] Based on the position of the centroid of the wing model in the simplified model of the tooling flag, the constraint equations for the centroid of the wing model and the upper surface of the tooling flag are established as follows:

[0068]

[0069] Among them, u1, u2, and u3 represent the three displacement components of the wing in the heading, span, and gravity directions, respectively; the superscripts F and w represent the tooling flag and the center of mass of the wing model, respectively.

[0070] In one implementation of the embodiment of the present invention, the implementation process of the above step 4 may include:

[0071] Step 4-1, dividing the simplified model of the tooling flag into grid units, wherein the maximum length, width and height of the grid units in the simplified model of the tooling flag shall not exceed 10% of the length, width and height of the tooling flag;

[0072] Step 4-2, input the mechanical boundary conditions and constraint equations into the finite element software, apply concentrated loads at the center of mass of the wing model according to the design results of the wing model, and solve it by the statics solution method to calculate the displacement field and stress field results of the simplified model of the tooling flag under the concentrated load; and obtain the maximum values ​​of the three displacement components u of the simplified model of the tooling flag in the heading direction, span direction, and gravity direction. 1,max 、u 2,max 、u 3,max ;

[0073] Step 4-3: Set the maximum values ​​of the three displacement components u of the simplified model of the tooling flag 1,max 、u 2,max 、u 3,max Compare with the design allowable values ​​[u1], [u2], [u3] to determine whether the design stiffness of the simplified model of the tooling flag meets the requirements.

[0074] In the specific implementation of this implementation, the method of judging whether the design stiffness of the simplified model of the tooling flag meets the requirements in step 4-3 is:

[0075] When the maximum values ​​of the three displacement components of the simplified model of the tooling flag are all less than the design allowable values, it is judged that the stiffness design of the simplified model of the tooling flag meets the requirements;

[0076] When the maximum value of at least one displacement component of the simplified model of the tooling flag is greater than or equal to the corresponding design allowable value, it is determined that the deformation of the simplified model of the tooling flag is out of tolerance; the following processing is performed:

[0077] By increasing the number of tooling flags in the current simplified tooling flag model, or increasing the thickness or height of the tooling flags, or changing the distribution position of the tooling flags; repeating steps 4-1 to 4-3 until the maximum values ​​of the three displacement components of the simplified tooling flag model are calculated to be less than the design allowable values, the simplified tooling flag model is used as a model for determining the force boundary.

[0078] In one implementation of the embodiment of the present invention, the implementation process of the above step 5 may include:

[0079] Step 5-1, based on the stress field results of the simplified model of the tooling flag that meets the stiffness design requirements under concentrated load, integrate the contact stress to obtain the support reaction force F of a single tooling flag in the simplified model of the tooling flag in the heading, span, and gravity directions. x 、F y 、F z :

[0080]

[0081] Among them, σ 11 , σ 22 , σ 33 is the stress component of one of the grid cells along the x, y, and z directions, and A is the inner surface area of ​​the bolt hole of the tooling flag;

[0082] Step 5-2, repeat step 5-1, and calculate the support reaction force F of each tooling flag in the heading direction, span direction, and gravity direction in turn. x 、F y 、F z , that is, to obtain the force boundary of the tooling flag in the large wing assembly.

[0083] The method for determining the force boundary of the large-scale wing assembly tooling flag provided by the embodiment of the present invention is, specifically, a method for calculating the force magnitude of each tooling flag in the wing assembly tooling, thereby evaluating the distribution position and quantity of the tooling flag. The technical solution provided by the embodiment of the present invention calculates the force state of each tooling flag in the wing assembly tooling by considering factors such as the geometric form of the tooling flag, the material type, the deadweight of the tooling flag, and the force and moment balance, and obtains the force boundary of all tooling flags; based on the calculated force boundary, on the one hand, it can be evaluated whether the number, geometric size, and structural form of the tooling flag can meet the deformation requirements of each stage of the assembly process; on the other hand, according to the force boundary, the position, quantity, and material of the tooling flag can be optimized and designed, and the rigidity of the large-scale wing tooling flag structure can be further improved to prevent the phenomenon of precision reduction caused by tooling precision deformation due to insufficient rigidity of the tooling flag. The method for determining the force boundary of the tooling flag provided by the present invention is a fast and effective calculation method.

[0084] Based on the force boundary determination method for a large wing assembly tooling flag provided in the above-mentioned embodiment of the present invention, an embodiment of the present invention further provides a computer-readable storage medium, including: a memory and a processor.

[0085] Wherein, the memory is used to store a computer-readable program;

[0086] The processor is used to implement the method for determining the force boundary of the tooling flag for large wing assembly as described in any one of the above items when executing the computer-readable program.

[0087] The following is a schematic illustration of an implementation example of the method for determining the force boundary of a large wing assembly tooling flag provided by an embodiment of the present invention.

[0088] Implementation Example

[0089] Reference Figures 1 to 5 As shown, the method for determining the force boundary of a large wing assembly tooling flag provided in this implementation example is implemented by the following steps:

[0090] Step 1: Establish a three-dimensional geometric model of the tooling flag in the large-scale wing assembly tooling, obtain a simplified model of the tooling flag through simplification, and determine the centroid of the wing model in the simplified model;

[0091] Step 2, setting mechanical boundary conditions for the simplified model of the tooling flag obtained in step 1;

[0092] Step 3, establishing constraint equations based on the simplified model of the tooling flag and the centroid of the wing model;

[0093] Step 4: by applying a concentrated load at the centroid of the wing model of the simplified model of the tooling flag, the displacement field and stress field results of the simplified model of the tooling flag under the concentrated load are solved to determine whether the design stiffness of the simplified model of the tooling flag meets the requirements;

[0094] Step 5: For the simplified model of the tooling flag obtained in step 4 that meets the stiffness design requirements, solve the stress field results of the simplified model of the tooling flag under the concentrated load, and calculate the force boundary of each tooling flag in the simplified model of the tooling flag.

[0095] In this implementation example, the implementation method of establishing a reasonably simplified finite element model of the assembly tooling flag in the above step 1 is as follows:

[0096] Step 1-1, using CAD software CATIA V5 R28 to establish a three-dimensional geometric model of a large wing assembly tooling flag, wherein all parts except the wing tooling flag 1, bolt hole 2, and tooling flag rib 3 in the large wing assembly tooling flag model are deleted to form a simplified tooling flag model.

[0097] In this step, it is required to ensure that the simplified model of the tooling flag is the same as the actual length, width and height of the original wing assembly tooling flag, and the distribution position, size, bolt hole position and bolt hole radius of the tooling flag in the simplified model are consistent with the actual wing tooling flag.

[0098] Step 1-2, establish the center of mass point 5 of the wing product in the simplified model of the tooling flag, and use the center of mass point to replace the entire wing model. The spatial coordinates of the center of mass point are consistent with the actual wing. In this implementation example, the coordinates of the center of mass point are (3000, 1200, 1000), and the wing mass is 1060kg. Figure 2 , which is a schematic diagram of a finite element model of a wing assembly tooling flag and a wing product centroid in a force boundary determination method provided in an embodiment of the present invention; Figure 2 The tooling flag 1, bolt hole 2, tooling flag rib 3, tooling flag end face 4, and wing product centroid 5 are shown in the figure.

[0099] In this implementation example, the implementation method of establishing a reasonable and simplified mechanical boundary condition in the above step 2 includes the following steps:

[0100] Step 2-1, according to the material type of the wing tooling flag, set the Young's modulus, Poisson's ratio, and material density of the actual tooling flag;

[0101] In this implementation example, for example, the Young's modulus and Poisson's ratio of the actual wing tooling flag are 210 GPa and 0.30 respectively, and the material density is 7.8×10-9 t / mm3.

[0102] Step 2-2, constraining 6 degrees of freedom at the bolt hole positions of each tooling flag in the simplified tooling flag model as the mechanical boundary conditions of the simplified tooling flag model.

[0103] In this implementation example, the method of establishing the constraint equation in the above step 3 is: based on the position of the centroid of the wing model in the simplified model of the tooling flag, the constraint equation is established for the centroid of the wing model and the upper surface of the tooling flag according to the following formula (1):

[0104]

[0105] Among them, u1, u2, and u3 represent the three displacement components of the wing heading, span direction, and gravity direction respectively; the superscripts F and w represent the tooling flag and the product center of mass respectively.

[0106] In this implementation example, the implementation process of solving the displacement field and stress field results of the simplified model of the tooling flag under the concentrated load in the above step 4 includes the following steps:

[0107] Step 4-1, divide the simplified model of the tooling flag into grid units, and the maximum length, width and height of the grid unit 6 in the simplified model of the tooling flag shall not exceed 10% of the length, width and height of the tooling flag; Figure 3 , which is a schematic diagram of a mesh unit model of a finite element in a force boundary determination method provided in an embodiment of the present invention.

[0108] Step 4-2, in ABAQUS 6.13 finite element software, based on the wing product design results, a concentrated load value is applied to the center of mass of the wing product. The load is 1060kg of the wing mass, and the gravity acceleration is 9.8N / kg. The statics solution method is used to calculate the displacement field and stress field results of the large wing assembly tooling flag under the concentrated load; Figure 4 , which is a schematic diagram of the stress field results calculated in the force boundary determination method provided in an embodiment of the present invention.

[0109] In step 4-2, the maximum values ​​of the three displacement components u of the wing assembly tooling flag heading, span direction, and along the gravity direction are obtained by the above-mentioned solution method. 1,max 、u 2,max 、u 3,max They are 0.002mm, 0.001mm and 0.005mm respectively.

[0110] Step 4-3, design the maximum allowable deformation values ​​[u1] = 0.1mm, [u2] = 0.1mm, [u3] = 0.2mm, and the maximum values ​​of the three displacement components of the wing assembly tooling flag heading, span direction, and along the gravity direction are u 1,max 、u 2,max 、u 3,maxIt is smaller than the maximum deformation value allowed by the design, indicating that the tooling flag design meets the requirements.

[0111] In this implementation example, the above step 5 solves the stress field result of the simplified model of the tooling flag under the concentrated load, and the implementation process of calculating the force boundary of each tooling flag in the simplified model of the tooling flag includes the following steps:

[0112] Step 5-1, integrate the contact stress by the following formula (2) to obtain the ground reaction force F in the ground model on any tooling flag in the simplified model in the heading direction, span direction, and along the gravity direction: x 、F y 、F z for:

[0113]

[0114] Among them, σ 11 , σ 22 , σ 33 is the stress component of a grid unit along the x, y, and z directions, and A is the inner surface area of ​​the bolt hole of the tooling flag;

[0115] Step 5-2, repeat step 5-1, and calculate the heading, span direction, and support reaction force F along the gravity direction of each tooling flag in turn. x 、F y 、F z ;like Figure 5 As shown, it is a schematic diagram of the heading direction, span direction, and support reaction force along the gravity direction of each tooling flag calculated in the force boundary determination method provided in an embodiment of the present invention.

[0116] Although the embodiments disclosed in the present invention are as above, the contents are only embodiments adopted to facilitate understanding of the present invention and are not intended to limit the present invention. Any technician in the field to which the present invention belongs can make any modifications and changes in the form and details of implementation without departing from the spirit and scope disclosed in the present invention, but the patent protection scope of the present invention shall still be subject to the scope defined in the attached claims.

Claims

1. A method for determining the force boundary of a tooling flag for large wing assembly, characterized in that: The following steps are involved: Step 1: Establish a three-dimensional geometric model of the tooling flag in the large-scale wing assembly tooling, obtain a simplified model of the tooling flag through simplification, and determine the centroid of the wing model in the simplified model; Step 2, setting mechanical boundary conditions for the simplified model of the tooling flag; Step 3, establishing constraint equations based on the simplified model of the tooling flag and the centroid of the wing model; Step 4: by applying a concentrated load at the centroid of the wing model of the simplified model of the tooling flag, the displacement field and stress field results of the simplified model of the tooling flag under the concentrated load are solved to determine whether the design stiffness of the simplified model of the tooling flag meets the requirements; Step 5: For the simplified model of the tooling flag obtained in step 4 that meets the stiffness design requirements, solve the stress field results of the simplified model of the tooling flag under the concentrated load, and calculate the force boundary of each tooling flag in the simplified model of the tooling flag.

2. A method for determining the force boundary of a tooling flag for large wing assembly according to claim 1, characterized in that: The step one comprises: Step 1-1, using CAD software to establish a three-dimensional geometric model of a tooling flag in a large wing assembly, and in the three-dimensional geometric model of the tooling flag, by deleting all parts except the wing tooling flag (1), bolt holes (2), and tooling flag ribs (3) in each tooling flag model, a simplified model of the tooling flag is formed; Step 1-2, set the center of mass point of the wing model in the simplified model of the tooling flag, and use the center of mass point to replace the entire wing model. The spatial coordinates of the center of mass point are consistent with the center of gravity of the wing model.

3. The method for determining the force boundary of a tooling flag for large wing assembly according to claim 2, characterized in that: The simplified model of the tooling flag obtained in step 1-1 has the following requirements: The simplified model of the tooling flag is required to be the same as the length, width and height of each tooling flag in the actual wing assembly, and the distribution position, size, bolt hole position and bolt hole radius of each tooling flag in the simplified model are required to be consistent with those of each tooling flag in the wing assembly.

4. The method for determining the force boundary of a tooling flag for large wing assembly according to claim 1, characterized in that: The second step comprises: Step 2-1, according to the material type of the tooling flag, set the Young's modulus, Poisson's ratio, and material density of the actual tooling flag; Step 2-2, setting 6-DOF constraints at the bolt hole positions of each tooling flag in the simplified tooling flag model as mechanical boundary conditions of the simplified tooling flag model.

5. The method for determining the force boundary of a tooling flag for large wing assembly according to claim 1, characterized in that: The step three comprises: Based on the position of the centroid of the wing model in the simplified model of the tooling flag, the constraint equations for the centroid of the wing model and the upper surface of the tooling flag are established as follows: Among them, u1, u2, and u3 represent the three displacement components of the wing in the heading, span, and gravity directions, respectively; the superscripts F and w represent the tooling flag and the center of mass of the wing model, respectively.

6. The method for determining the force boundary of a tooling flag for large wing assembly according to claim 1, characterized in that: The fourth step comprises: Step 4-1, dividing the simplified model of the tooling flag into grid units, wherein the maximum length, width and height of the grid units in the simplified model of the tooling flag shall not exceed 10% of the length, width and height of the tooling flag; Step 4-2, input the mechanical boundary conditions and constraint equations into the finite element software, apply concentrated loads at the center of mass of the wing model according to the design results of the wing model, and solve it by the statics solution method to calculate the displacement field and stress field results of the simplified model of the tooling flag under the concentrated load; and obtain the maximum values ​​of the three displacement components u of the simplified model of the tooling flag in the heading direction, span direction, and gravity direction. 1,max 、u 2,max 、u 3,max ; Step 4-3: Set the maximum values ​​of the three displacement components u of the simplified model of the tooling flag 1,max 、u 2,max 、u 3,max Compare with the design allowable values ​​[u1], [u2], [u3] to determine whether the design stiffness of the simplified model of the tooling flag meets the requirements.

7. A method for determining the force boundary of a tooling flag for large wing assembly according to claim 6, characterized in that: The method for judging whether the design stiffness of the simplified model of the tooling flag meets the requirements in step 4-3 is: When the maximum values ​​of the three displacement components of the simplified model of the tooling flag are all less than the design allowable values, it is judged that the stiffness design of the simplified model of the tooling flag meets the requirements; When the maximum value of at least one displacement component of the simplified model of the tooling flag is greater than or equal to the corresponding design allowable value, it is determined that the deformation of the simplified model of the tooling flag is out of tolerance; the following processing is performed: By increasing the number of tooling flags in the current simplified tooling flag model, or increasing the thickness or height of the tooling flags, or changing the distribution position of the tooling flags; repeating steps 4-1 to 4-3 until the maximum values ​​of the three displacement components of the simplified tooling flag model are calculated to be less than the design allowable values, the simplified tooling flag model is used as a model for determining the force boundary.

8. A method for determining the force boundary of a tooling flag for large wing assembly according to any one of claims 1 to 7, characterized in that: The step five comprises: Step 5-1, based on the stress field results of the simplified model of the tooling flag that meets the stiffness design requirements under concentrated load, integrate the contact stress to obtain the support reaction force F of a single tooling flag in the simplified model of the tooling flag in the heading, span, and gravity directions. x 、F y 、F z : Among them, σ 11 , σ 22 , σ 33 is the stress component of one of the grid cells along the x, y, and z directions, and A is the inner surface area of ​​the bolt hole of the tooling flag; Step 5-2, repeat step 5-1, and calculate the support reaction force F of each tooling flag in the heading direction, span direction, and gravity direction in turn. x 、F y 、F z , that is, to obtain the force boundary of the tooling flag in the large wing assembly.

9. A computer-readable storage medium, characterized in that: include: Memory and processor; Wherein, the memory is used to store a computer-readable program; The processor is used to implement the method for determining the force boundary of a tooling flag for large wing assembly according to any one of claims 1 to 8 when executing a computer-readable program.

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