A method for determining the force boundary of a large wing assembly tooling flag

Abstract

This invention discloses a method for determining the force boundary of a tooling flag used in large wing assembly, comprising: Step 1, establishing a three-dimensional geometric model of the tooling flag in the large wing assembly tooling, and obtaining a simplified model of the tooling flag through simplification processing, and determining the center of mass 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 center of mass of the wing model; Step 4, applying a concentrated load to the center of mass of the wing model in the simplified model of the tooling flag, and solving for the displacement field and stress field results of the simplified model of the tooling flag under the concentrated load, in order to determine whether the design stiffness of the simplified model of the tooling flag meets the requirements; Step 5, solving for the stress field results of the simplified model of the tooling flag under the concentrated load on the simplified model of the tooling flag obtained in Step 4 that meets the stiffness design requirements, and calculating the force boundary of each tooling flag in the simplified model of the tooling flag. The technical solution provided by the embodiments of the present invention solves the problem that the traditional design method for the stress boundary of the tooling flag does not take into account the actual spatial distribution of the tooling flag, resulting in a large difference from the actual situation. This leads to inaccurate stress on the designed tooling flag, unreasonable distribution position and quantity of the tooling flag, and consequently, excessive stress on local tooling flags, causing deformation of the entire wing tooling.

Description

Technical Field

[0001] This invention relates to, but is not limited to, the field of wing assembly technology, and particularly to a method for determining the force boundary of a tooling flag used in the assembly of large wings. Background Technology

[0002] In the assembly of large airfoils, the tooling flags on the assembly fixtures directly affect positioning accuracy and efficiency. To prevent a decrease in assembly accuracy due to deformation of the tooling flags during use, it is necessary to calculate the force on each tooling flag, i.e., determine its force boundary. This allows for the evaluation of the distribution and quantity of the tooling flags, avoiding situations where unreasonable design placement and quantity of the flags lead to excessive localized stress on the flags, thereby causing deformation of the entire airfoil fixture.

[0003] The traditional design method for the stress boundary of the work flags only calculates the stress boundary of each work flag by dividing the wing weight by the number of work flags, without considering the actual spatial distribution of the work flags. This results in a significant difference from the actual situation, leading to inaccurate stress on the designed work flags and unreasonable distribution positions and numbers of work flags. Summary of the Invention

[0004] The purpose of this invention is to solve the above-mentioned technical problems. This invention provides a method for determining the stress boundary of tooling flags for large wing assembly. This method addresses the problem that traditional design methods for the stress boundary of tooling flags do not consider the actual spatial distribution of tooling flags, resulting in significant differences from the actual situation. Consequently, the designed stress on the tooling flags is inaccurate, and the resulting distribution position and quantity of tooling flags are unreasonable. This leads to excessive stress on local tooling flags, causing deformation of the entire wing tooling.

[0005] The technical solution of the present invention: In a first aspect, embodiments of the present invention provide a method for determining the force boundary of a tooling flag used in the assembly of large airfoils, comprising:

[0006] Step 1: Establish a three-dimensional geometric model of the tooling flag in the large wing assembly tooling, and obtain a simplified model of the tooling flag through simplification processing. Determine the center of mass of the wing model in the simplified model.

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

[0008] Step 3: Establish constraint equations based on the simplified model of the tooling flag and the center of mass of the wing model;

[0009] Step 4: By applying a concentrated load to the center of mass of the wing model of the simplified tooling flag model, the displacement field and stress field results of the simplified tooling flag model under the concentrated load are obtained to determine whether the design stiffness of the simplified tooling flag model meets the requirements.

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

[0011] Optionally, in the method for determining the force boundary of a tooling flag for assembling a large wing as described above, step one includes:

[0012] Step 1-1: Use CAD software to create a three-dimensional geometric model of the tooling flag in the large wing assembly. In the three-dimensional geometric model of the tooling flag, delete all parts except wing tooling flag 1, bolt hole 2, and tooling flag rib 3 to form a simplified tooling flag model.

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

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

[0015] The simplified model of the tooling flags must have the same length, width, and height dimensions as the tooling flags in the actual wing assembly. Furthermore, the distribution, size, bolt hole position, and bolt hole radius of each tooling flag in the simplified model must be consistent with those of each tooling flag in the actual wing assembly.

[0016] Optionally, in the method for determining the force boundary of a tooling flag for assembling a large wing as described above, step two includes:

[0017] Step 2-1: Based on 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: Set 6-degree-of-freedom constraints at the bolt hole positions of each tool flag in the simplified tool flag model as the mechanical boundary conditions of the simplified tool flag model.

[0019] Optionally, in the method for determining the force boundary of a tooling flag for assembling large airfoils as described above, step three includes:

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

[0021]

[0022] Where u1, u2, and u3 represent the three displacement components of the wing in the heading, spanwise, and gravitational direction, respectively; the superscripts F and w represent the tool flag and the center of mass of the wing model, respectively.

[0023] Optionally, in the method for determining the force boundary of a tooling flag for assembling a large wing as described above, step four includes:

[0024] Step 4-1: Divide the simplified tooling flag model into mesh cells. The maximum dimensions of the mesh cells in the simplified tooling flag model shall not exceed 10% of the length, width and height of the tooling flag.

[0025] Step 4-2: In the finite element software, based on the wing model design results, a concentrated load is applied to the center of mass of the wing model, and the displacement and stress fields of the simplified tooling flag model under the concentrated load are calculated using the static solution method; and the maximum values ​​u of the three displacement components of the simplified tooling flag model in the heading, spanwise, and gravity directions are obtained. 1,max u 2,max u 3,max ;

[0026] Step 4-3, simplify the tooling flag model by calculating the maximum value of the three displacement components u. 1,max u 2,max u 3,max The design stiffness of the simplified tooling flag model is compared with the design allowable values ​​[u1], [u2], and [u3] to determine whether the design stiffness meets the requirements.

[0027] Optionally, in the method for determining the force boundary of the tooling flag for assembling large airfoils as described above, the method for determining whether the design stiffness of the simplified tooling flag model meets the requirements in step 4-3 is as follows:

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

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

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

[0031] Optionally, in the method for determining the force boundary of a tooling flag for assembling a large wing as described above, step five includes:

[0032] Step 5-1: Based on the stress field results of the simplified tooling flag model 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 heading, spanwise, and gravity directions in the simplified tooling flag model. x F y F z :

[0033]

[0034] Where, σ 11 σ 22 σ 33 Let A be the stress component of one of the mesh elements along the x, y, z directions, and let A be the inner surface area of ​​the bolt hole of the tooling flag.

[0035] Step 5-2: Repeat step 5-1 to calculate the support reaction force F for each tool flag in the heading, span, and gravity directions. x F y F z This means obtaining the force boundary of the tooling flag in the assembly of a large wing.

[0036] In a second aspect, embodiments of the present invention also provide a computer-readable storage medium, including: a memory and a processor;

[0037] The memory is used to store computer-readable programs;

[0038] The processor is configured to, when executing a computer-readable program, implement the method for determining the force boundary of a tooling flag for assembling large wings as described above.

[0039] The beneficial effects of this invention: This invention provides a method for determining the force boundary of tooling flags used in large wing assembly. Specifically, it is a method for evaluating the distribution and quantity of tooling flags by calculating the force magnitude of each tooling flag in the wing assembly tooling. The technical solution provided by this invention calculates the force state of each tooling flag in the wing assembly tooling by considering factors such as the tooling flag's geometry, material type, weight, force and moment balance, thus obtaining the force boundary of all tooling flags. Based on the calculated force boundary, on the one hand, it can evaluate whether the number, geometry, and structural form of the tooling flags can meet the deformation requirements at each stage of the assembly process; on the other hand, it can optimize the design of the tooling flag's position, quantity, and material according to the force boundary, further improving the stiffness of the large wing tooling flag structure and preventing the decrease in accuracy caused by tooling precision deformation due to insufficient tooling flag stiffness. The tooling flag force boundary determination method provided by this invention is a fast and effective calculation method. Attached Figure Description

[0040] The accompanying drawings are provided to further understand the technical solutions of the present invention and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of the present invention and do not constitute a limitation on the technical solutions of the present invention.

[0041] Figure 1 This is a flowchart of a method for determining the force boundary of a large wing assembly tooling flag proposed in this invention.

[0042] Figure 2 A schematic diagram of the finite element model of the wing assembly tooling flag and the center of mass of the wing product in the force boundary determination method provided in the embodiments of the present invention;

[0043] Figure 3 A schematic diagram of the finite element mesh model in the force boundary determination method provided in the embodiments of the present invention;

[0044] Figure 4 A schematic diagram of the stress field results calculated in the force boundary determination method provided in the embodiments of the present invention;

[0045] Figure 5 This is a schematic diagram of the heading, span, and gravity-direction support reaction force of each tooling flag calculated in the force boundary determination method provided in the embodiments of the present invention.

[0046] Explanation of reference numerals in the attached figures:

[0047] 1. Tooling flag; 2. Bolt holes; 3. Tooling flag ribs; 4. Tooling flag end face; 5. Wing product center of mass; 6. Grid unit. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

[0049] The background section has already explained the important role of each tooling flag in the assembly of large airfoils, and the necessity of determining the stress boundary of each tooling flag. However, traditional design methods for the stress boundary of tooling flags do not consider the actual spatial distribution of the tooling flags, resulting in significant differences from the actual situation. This leads to inaccurate stress on the designed tooling flags, and consequently, unreasonable distribution positions and quantities of tooling flags.

[0050] To address the aforementioned issues, this invention proposes a method for determining the force boundary of tooling flags used in large wing assembly. By calculating the force magnitude of each tooling flag in the wing assembly tooling, the distribution position and quantity of the tooling flags are evaluated.

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

[0052] Figure 1 This is a flowchart illustrating a method for determining the force boundary of a large wing assembly tooling flag, as proposed in this invention. The method for determining the force boundary of a large wing assembly tooling flag provided by this invention includes the following steps:

[0053] Step 1: Establish a three-dimensional geometric model of the tooling flag in the large wing assembly tooling, and obtain a simplified model of the tooling flag through simplification processing. Determine the center of mass of the wing model in the simplified model.

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

[0055] Step 3: Establish constraint equations based on the simplified model of the tooling flag and the center of mass of the wing model;

[0056] Step 4: By applying a concentrated load to the center of mass of the wing model of the simplified tooling flag model, the displacement field and stress field results of the simplified tooling flag model under the concentrated load are obtained to determine whether the design stiffness of the simplified tooling flag model meets the requirements.

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

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

[0059] Step 1-1: Use CAD software to create a three-dimensional geometric model of the tooling flag in the large wing assembly. In the three-dimensional geometric model of the tooling flag, delete all parts except wing tooling flag 1, bolt hole 2, and tooling flag rib 3 to form a simplified tooling flag model.

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

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

[0062] The simplified model of the tooling flags must have the same length, width, and height dimensions as the tooling flags in the actual wing assembly. Furthermore, the distribution, size, bolt hole position, and bolt hole radius of each tooling flag in the simplified model must be consistent with those of each tooling flag in the actual wing assembly.

[0063] In one implementation of this invention, the process of step two above may include:

[0064] Step 2-1: Based on 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: Set 6-degree-of-freedom constraints at the bolt hole positions of each tool flag in the simplified tool flag model as the mechanical boundary conditions of the simplified tool flag model.

[0066] In one implementation of this invention, step three may include:

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

[0068]

[0069] Where 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 tool flag and the center of mass of the wing model, respectively.

[0070] In one implementation of this invention, step four may include:

[0071] Step 4-1: Divide the simplified tooling flag model into mesh cells. The maximum dimensions of the mesh cells in the simplified tooling flag model 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. Based on the wing model design results, apply a concentrated load to the center of mass of the wing model and solve it using the statics method. Calculate the displacement and stress fields of the simplified tooling flag model under the concentrated load; and obtain the maximum values ​​u of the three displacement components of the simplified tooling flag model in the heading, spanwise, and gravity directions. 1,max u 2,max u 3,max ;

[0073] Step 4-3, simplify the tooling flag model by calculating the maximum value of the three displacement components u. 1,max u 2,max u 3,max The design stiffness of the simplified tooling flag model is compared with the design allowable values ​​[u1], [u2], and [u3] to determine whether the design stiffness meets the requirements.

[0074] In practice, the method for determining whether the design stiffness of the simplified tooling flag model meets the requirements in step 4-3 is as follows:

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

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

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

[0078] In one implementation of this invention, step five may include:

[0079] Step 5-1: Based on the stress field results of the simplified tooling flag model 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 heading, spanwise, and gravity directions in the simplified tooling flag model. x F y F z :

[0080]

[0081] Where, σ 11 σ 22 σ 33 Let A be the stress component of one of the mesh elements along the x, y, z directions, and let A be the inner surface area of ​​the bolt hole of the tooling flag.

[0082] Step 5-2: Repeat step 5-1 to calculate the support reaction force F for each tool flag in the heading, span, and gravity directions. x F y F z This means obtaining the force boundary of the tooling flag in the assembly of a large wing.

[0083] The method for determining the force boundary of tooling flags for large wing assembly provided by this invention specifically evaluates the distribution and quantity of tooling flags by calculating the force magnitude of each tooling flag in the wing assembly tooling. The technical solution provided by this invention calculates the force state of each tooling flag in the wing assembly tooling by considering factors such as the tooling flag's geometry, material type, self-weight, force and moment balance, thereby obtaining the force boundary of all tooling flags. Based on the calculated force boundary, on the one hand, it can evaluate whether the number, geometric dimensions, and structural form of the tooling flags can meet the deformation requirements at each stage of the assembly process; on the other hand, it can optimize the design of the tooling flag's position, quantity, and material according to the force boundary, further improving the stiffness of the large wing tooling flag structure and preventing the decrease in accuracy caused by tooling accuracy deformation due to insufficient tooling flag stiffness. The method for determining the force boundary of tooling flags provided by this invention is a fast and effective calculation method.

[0084] Based on the method for determining the force boundary of a tooling flag for assembling large wings provided in the above embodiments of the present invention, the present invention also provides a computer-readable storage medium, including: a memory and a processor.

[0085] The memory is used to store computer-readable programs;

[0086] The processor is configured to, when executing a computer-readable program, implement the method for determining the force boundary of a tooling flag for assembling large wings as described above.

[0087] The following is an illustrative description of the implementation method for determining the force boundary of a large wing assembly tooling flag provided by the present invention, through an implementation example.

[0088] Implementation Example

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

[0090] Step 1: Establish a three-dimensional geometric model of the tooling flag in the large wing assembly tooling, and obtain a simplified model of the tooling flag through simplification processing. Determine the center of mass of the wing model in the simplified model.

[0091] Step 2: Set mechanical boundary conditions for the simplified tooling flag model obtained in Step 1;

[0092] Step 3: Establish constraint equations based on the simplified model of the tooling flag and the center of mass of the wing model;

[0093] Step 4: By applying a concentrated load to the center of mass of the wing model of the simplified tooling flag model, the displacement field and stress field results of the simplified tooling flag model under the concentrated load are obtained to determine whether the design stiffness of the simplified tooling flag model meets the requirements.

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

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

[0096] Step 1-1: Use CAD software CATIA V5 R28 to create a three-dimensional geometric model of the large wing assembly tooling flag. In this model, delete all parts except wing tooling flag 1, bolt holes 2, and tooling flag ribs 3 to form a simplified tooling flag model.

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

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

[0099] In this implementation example, the method for establishing reasonably simplified mechanical boundary conditions in step two above includes the following steps:

[0100] Step 2-1: Based on 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 instance, the Young's modulus and Poisson's ratio of the actual wing tooling flag are set to 210 GPa and 0.30, respectively, and the material density is set to 7.8 × 10-9 t / mm3.

[0102] Step 2-2: Constrain the bolt hole positions of each tool flag in the simplified tool flag model with 6 degrees of freedom, as the mechanical boundary conditions of the simplified tool flag model.

[0103] In this implementation example, the constraint equations in step three above are established as follows: Based on the position of the centroid of the wing model in the simplified model of the tooling flag, constraint equations are 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 in the heading, span, and gravity directions, respectively; the superscripts F and w represent the tooling flag and the product center of mass, respectively.

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

[0107] Step 4-1: Mesh the simplified tooling flag model. The maximum dimensions of each mesh cell in the simplified tooling flag model should not exceed 10% of the total dimensions of the tooling flag. Figure 3 The diagram shown is a schematic of the finite element mesh model in the force boundary determination method provided in the 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 is applied to the center of mass of the wing product. The load is taken as the wing mass of 1060 kg and the gravitational acceleration as 9.8 N / kg. The displacement and stress fields of the large wing assembly tooling flag under the concentrated load are calculated using the static method. Figure 4 The diagram shown is a schematic representation of the stress field results calculated in the force boundary determination method provided in this embodiment of the invention.

[0109] In step 4-2, the maximum values ​​of the three displacement components u of the wing assembly tool flag in the heading, spanwise, and gravity direction are obtained through the above calculation method. 1,max u 2,max u 3,max The thicknesses 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 obtain the maximum values ​​of the three displacement components (heading, spanwise, and along the gravity direction) of the wing assembly tooling. 1,max u 2,max u 3,maxIf the deformation value is less than the maximum allowable value, it means that the tooling flag design meets the requirements.

[0111] In this implementation example, step five above, which solves for the stress field of the simplified tooling flag model under concentrated load, and calculates the force boundary of each tooling flag in the simplified tooling flag model, includes the following steps:

[0112] Step 5-1: Integrate the contact stress using the following formula (2) to obtain the ground reaction force F between the ground in the ground model and any tool flag in the simplified model in the heading, span, and gravity direction. x F y F z for:

[0113]

[0114] Where, σ 11 σ 22 σ 33 Let A be the stress components of a mesh element along the x, y, z directions, and let A be 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, and gravity-directed support reaction force F for each tool flag in turn. x F y F z ;like Figure 5 The diagram shown is a schematic diagram of the heading, span, and gravity-direction support reaction forces of each tooling flag calculated in the force boundary determination method provided in the embodiment of the present invention.

[0116] While the embodiments disclosed in this invention are as described above, they are merely illustrative of the embodiments to facilitate understanding of the invention and are not intended to limit the invention. Any person skilled in the art to which this invention pertains may make any modifications and variations in the form and details of the implementation without departing from the spirit and scope disclosed herein; however, the scope of patent protection for this invention shall still be determined by the scope defined in the appended claims.

Claims

1. A method for determining the force boundary of a tooling flag used in the assembly of large airfoils, characterized in that, Includes the following steps: Step 1: Establish a three-dimensional geometric model of the tooling flag in the large wing assembly tooling, and obtain a simplified model of the tooling flag through simplification processing. Determine the center of mass of the wing model in the simplified model. Step 2: Set mechanical boundary conditions for the simplified model of the tooling flag; Step 3: Establish constraint equations based on the simplified model of the tooling flag and the center of mass of the wing model; Step 4: By applying a concentrated load to the center of mass of the wing model of the simplified tooling flag model, the displacement field and stress field results of the simplified tooling flag model under the concentrated load are obtained to determine whether the design stiffness of the simplified tooling flag model meets the requirements. Step 5: For the simplified tooling flag model that meets the stiffness design requirements obtained in Step 4, solve the stress field results of the simplified tooling flag model under concentrated load, and calculate the force boundary of each tooling flag in the simplified tooling flag model. Step three includes: Based on the position of the center of mass of the wing model in the simplified model of the tooling flag, the constraint equations for the center of mass of the wing model and the upper surface of the tooling flag are established as follows: ； in, , , These represent the three displacement components of the wing in the heading, span, and gravity directions, respectively; the superscripts F and w represent the tool flag and the center of mass of the wing model, respectively. Step four includes: Step 4-1: Mesh the simplified tooling flag model. The maximum dimensions of the mesh cells in the simplified tooling flag model 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. Based on the wing model design results, apply a concentrated load to the center of mass of the wing model and solve it using the statics method. Calculate the displacement and stress fields of the simplified tooling flag model under the concentrated load; and obtain the maximum values ​​of the three displacement components of the simplified tooling flag model in the heading, spanwise, and gravity directions. , , ; Step 4-3: Calculate the maximum value of the three displacement components of the simplified model of the tooling flag. , , With design allowable values , , A comparison is made to determine whether the design stiffness of the simplified tooling flag model meets the requirements.

2. The method for determining the force boundary of a tooling flag used in the assembly of large airfoils according to claim 1, characterized in that, Step one includes: Step 1-1: Use CAD software to establish a three-dimensional geometric model of the tooling flag in the assembly of a large wing. In the three-dimensional geometric model of the tooling flag, delete all parts except the wing tooling flag (1), bolt holes (2), and tooling flag ribs (3) in each tooling flag model to form a simplified tooling flag model. Steps 1-2: In the simplified model of the tooling flag, set the center of mass of the wing model, and use the center of mass to replace the entire wing model. The spatial coordinates of the center of mass are consistent with the center of gravity of the wing model.

3. The method for determining the force boundary of a tooling flag used in the assembly of large airfoils 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 flags must have the same length, width, and height dimensions as the tooling flags in the actual wing assembly. Furthermore, the distribution, size, bolt hole position, and bolt hole radius of each tooling flag in the simplified model must be consistent with those of each tooling flag in the actual wing assembly.

4. The method for determining the force boundary of a tooling flag used in the assembly of large airfoils according to claim 1, characterized in that, Step two includes: Step 2-1: Based on 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: Set 6-degree-of-freedom constraints at the bolt hole positions of each tool flag in the simplified tool flag model as the mechanical boundary conditions of the simplified tool flag model.

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

6. A method for determining the force boundary of a tooling flag used in the assembly of large airfoils according to any one of claims 1 to 5, characterized in that, Step five includes: Step 5-1: Based on the stress field results of the simplified tooling flag model that meets the stiffness design requirements under concentrated load, integrate the contact stress to obtain the support reactions of a single tooling flag in the heading, spanwise, and gravity directions in the simplified tooling flag model. , , : ； in, , , Let A be the stress component of one of the mesh elements along the x, y, z directions, and let A be the inner surface area of ​​the bolt hole of the tooling flag. Step 5-2: Repeat step 5-1 to calculate the support reactions of each tooling flag in the heading, span, and gravity directions. , , This means obtaining the force boundary of the tooling flag in the assembly of a large wing.

7. A computer-readable storage medium, characterized in that, include: Memory and processor; The memory is used to store computer-readable programs; The processor is configured to implement, when executing a computer-readable program, the method for determining the force boundary of a tooling flag for assembling a large wing as described in any one of claims 1 to 6.

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