Rapid calculation method for wing bending deformation

Abstract

According to the wing bending deformation rapid calculation method, the wing structure can generate bending deformation under the action of the external load. When engineering analysis is carried out, the size of deformation generally needs to be calculated with the help of a finite element technology, but due to the fact that design variables are many, the efficiency of a fine finite element analysis method is low. The design comprises the steps that a cubic polynomial of wing bending deformation in the spanwise direction is constructed based on the assumption that the spanwise total length is not changed after wing deformation; obtaining boundary conditions of a fixed wing root and a free end of a wing tip, and calculating an undetermined coefficient of a polynomial; and substituting the undetermined coefficient of the polynomial into the deflection curve equation to obtain the bending deformation of the wing structure in the spanwise direction. By means of the polynomial fitting technology, the displacement deformation result of the wing structure under the load effect is approximately calculated, bending deformation of the wing structure can be rapidly obtained on the premise that certain precision is guaranteed, and the good engineering application effect is achieved.

Description

Technical Field

[0001] The present application belongs to the field of wing structure design, and in particular relates to a method for quickly calculating wing bending deformation. Background Art

[0002] Since the deformation of the wing after being loaded is mainly bending and torsion deformation, the bending and torsion deformation of the wing will in turn affect the distribution of aerodynamic loads on the wing surface, thereby affecting the lift and maneuverability of the aircraft. At the same time, the change of aerodynamic loads will further affect the deformation of the aircraft wing structure. When performing simulation calculations on the bending deformation of the aircraft wing structure, the amount of calculation will increase due to the large number of design variables and complex parameters.

[0003] Therefore, how to achieve efficient simulation calculation of aircraft wing structure bending deformation is a problem that needs to be solved. Summary of the invention

[0004] The purpose of this application is to provide a method for quickly calculating wing bending deformation, so as to solve the problem of many design variables and complex parameters in the existing simulation calculation of bending deformation of aircraft wing structure.

[0005] The technical solution of the present application is: a method for quickly calculating wing bending deformation, comprising: Based on the assumption that the total span length of the wing remains unchanged after deformation, a cubic polynomial of the wing bending deformation along the span direction is constructed; Obtain the boundary conditions of the fixed wing root and the free end of the wing tip, and calculate the unknown coefficients of the cubic polynomial through the analytical model including properties, loads and constraints; Substituting the unknown coefficients of the cubic polynomial into the deflection curve equation, the bending deformation of the wing structure along the span direction is obtained.

[0006] Preferably, the cubic polynomial is: ;in: are the unknown coefficients of the polynomial, is the spanwise coordinate value of the local coordinate system after the wing is deformed.

[0007] Preferably, the boundary conditions of the fixed wing root and the free end of the wing tip include: ; in, is the boundary condition at the wing root, for The first derivative of is the boundary condition at the free end of the wing tip, for The second derivative of is the wing tip deflection, is the deflection of the wing tip free end.

[0008] Preferably, the bending deformation of the wing structure along the span direction is: , where is the wing tip deflection, is the deflection of the wing tip free end.

[0009] Preferably, the unknown coefficients of the cubic polynomial are , where is the wing tip deflection, is the deflection of the wing tip free end.

[0010] The fast calculation method of wing bending deformation of the present application uses polynomial fitting technology to approximate the displacement deformation results of the wing structure under load, and can quickly obtain the bending deformation of the wing structure while ensuring a certain accuracy, and has a good engineering application effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the technical solution provided by the present application, the following is a brief introduction to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of the present application.

[0012] Figure 1 This is a schematic diagram of the overall process of this application; Figure 2 This is a schematic diagram of the wing structure of this application; Figure 3 An analysis model including properties, loads and constraints for this application; Figure 4 This is a schematic diagram of the bending deformation results of the wing structure of this application. DETAILED DESCRIPTION

[0013] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0014] A fast calculation method for wing bending deformation, such as Figure 1 , including the following steps: Step S100, constructing a cubic polynomial for the bending deformation of the wing along the span direction based on the assumption that the total span length of the wing remains unchanged after deformation ; in: are the unknown coefficients of the polynomial, is the spanwise coordinate value of the local coordinate system after the wing is deformed.

[0015] Wing structure Figure 2As shown, in the local coordinate system, the origin is defined as the outer end point of the previous wing after deformation, and the coordinate axis is parallel to the global coordinate system.

[0016] Step S200, obtain the boundary conditions of the fixed wing root and the free end of the wing tip, and calculate the undetermined coefficients of the cubic polynomial through the analysis model including attributes, loads and constraints. The undetermined coefficients of the cubic polynomial are ; In the formula, is the wing tip deflection, is the deflection of the wing tip free end.

[0017] The boundary conditions for the fixed wing root and free wing tip include: ; in, is the boundary condition at the wing root, for The first derivative of is the boundary condition at the free end of the wing tip, for The second derivative of is the wing tip deflection, is the deflection of the wing tip free end.

[0018] The analysis model including properties, loads and constraints is as follows Figure 3 As shown in the figure, the aerodynamic loads are connected to the analysis model nodes by spatial interpolation, and the ends are fixed.

[0019] Step S300: Substitute the unknown coefficients of the cubic polynomial into the deflection curve equation to obtain the bending deformation of the wing structure along the span direction. ; From the deflection curve equation, we can see that we only need to know the wing tip deflection The bending deformation of the wing structure along the span direction can be calculated, such as Figure 4 .

[0020] In summary, the wing structure will bend and deform under the action of external loads. When conducting engineering analysis on it, it is usually necessary to use finite element technology to calculate the size of the deformation. However, due to the large number of design variables, the efficiency of the method of fine finite element analysis is low.

[0021] The present application uses the polynomial fitting technology to approximately calculate the displacement deformation results of the wing structure under the action of load, and can quickly obtain the bending deformation of the wing structure while ensuring a certain accuracy, which has a good engineering application effect.

[0022] Finally, it should be noted that: the drawings of the embodiments disclosed in the present invention only involve structures related to the embodiments disclosed in the present invention, and other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of the present invention can be combined with each other; Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for rapid calculation of wing bending deformation, characterized in that: include: Based on the assumption that the total span length of the wing remains unchanged after deformation, a cubic polynomial of the wing bending deformation along the span direction is constructed; Obtain the boundary conditions of the fixed wing root and the free end of the wing tip, and calculate the unknown coefficients of the cubic polynomial through the analytical model including properties, loads and constraints; Substituting the unknown coefficients of the cubic polynomial into the deflection curve equation, the bending deformation of the wing structure along the span direction is obtained.

2. The method for rapid calculation of wing bending deformation according to claim 1, characterized in that: The cubic polynomial is: ;in: are the unknown coefficients of the polynomial, is the spanwise coordinate value of the local coordinate system after the wing is deformed.

3. The method for rapid calculation of wing bending deformation according to claim 1, characterized in that: The boundary conditions of the fixed wing root and the free end of the wing tip include: ； in, is the boundary condition at the wing root, for The first derivative of is the boundary condition at the free end of the wing tip, for The second derivative of is the wing tip deflection, is the deflection of the wing tip free end.

4. The method for rapid calculation of wing bending deformation according to claim 1, characterized in that: The bending deformation of the wing structure along the span direction is: , where is the wing tip deflection, is the deflection of the wing tip free end.

5. The method for rapid calculation of wing bending deformation according to claim 2, characterized in that: The unknown coefficients of the cubic polynomial are , where is the wing tip deflection, is the deflection of the wing tip free end.

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