Aircraft plane symmetry double fork beam type wing torsional stiffness equivalent calculation method

Abstract

The application belongs to the technical field of plane symmetric double-beam wing structure strength design of an airplane, and particularly relates to a plane symmetric double-beam wing torsional rigidity equivalent calculation method, which simplifies the plane symmetric double-beam wing into a double-beam with a corresponding cross section, establishes a plane symmetric double-beam calculation model, constructs a calculation formula according to the same torsional angle of the load action point of the double-beam and the equivalent cantilever beam under the action of the same torque load, and thus the torsional rigidity of the equivalent cantilever beam of the double-beam is quickly calculated.

Description

Technical Field

[0001] This application belongs to the field of strength design technology for aircraft planar symmetric double-spandrel wing structures, specifically involving an equivalent calculation method for the torsional stiffness of an aircraft planar symmetric double-spandrel wing. Background Technology

[0002] Torsional load is one of the main loads borne by a planar symmetric double-spandrel wing. The torsional stiffness of a planar symmetric double-spandrel wing is a key aspect of structural strength design. Quickly solving for the torsional stiffness of a planar symmetric double-spandrel wing is a crucial problem that must be solved in the structural strength design of such wings.

[0003] Currently, the strength design of aircraft wings is mostly based on finite element analysis, which is well applicable to the analysis of wing stress, strain, displacement, etc. However, calculating the overall torsional stiffness of a planar symmetrical double-spar wing is time-consuming and laborious, and the analysis is still unclear, making it difficult to meet the need for rapid iteration in the strength design of planar symmetrical double-spar wing structures.

[0004] This application is made in view of the aforementioned technical deficiencies.

[0005] It should be noted that the above background information is only used to assist in understanding the inventive concept and technical solution of this application, and it does not necessarily belong to the prior art of this patent application. In the absence of clear evidence that the above information was disclosed on the filing date of this application, the above background information should not be used to evaluate the novelty and inventiveness of this application. Summary of the Invention

[0006] The purpose of this application is to provide an equivalent calculation method for the torsional stiffness of a plane-symmetric double-spar wing of an aircraft, so as to overcome or mitigate at least one of the known technical defects.

[0007] The technical solution of this application is:

[0008] An equivalent calculation method for the torsional stiffness of a plane-symmetric double-spar wing for aircraft includes:

[0009] Step 1: Simplify the box segment composed of wing panels and beams into a beam and establish a planar symmetric double-forked beam calculation model. The double-forked beam consists of a front beam OA and a rear beam OB. The front beam OA and the rear beam OB are fixed at point O and are symmetrically distributed about the xz plane. The root of the double-forked beam is located on the symmetry plane of the aircraft and is fixedly constrained.

[0010] Step 2: Determine the material parameters and geometric parameters of the double-fork beam: the elastic modulus E of the front beam OA and the rear beam OB, the shear modulus G of the front beam OA and the rear beam OB, the length L of the front beam OA and the rear beam OB, and the included angle α between the front beam OA and the rear beam OB, and solve for the moment of inertia I of the front beam OA and the rear beam OB and the polar moment of inertia J of the front beam OA and the rear beam OB according to the cross-sectional shape parameters of the double-fork beam;

[0011] Step 3: Apply a torque T along the x-direction at point O of the double-fork beam O , and calculate the torsion angle θ at point O of the double-fork beam O ;

[0012] Step 4: Apply a torque T along the x-direction at point O of the equivalent cantilever beam of the double-fork beam O , which represents the torsion angle θ' at point O of the equivalent cantilever beam of the double-fork beam O :

[0013] Step 5: Set θ' O =θ O to obtain the torsional stiffness of the equivalent cantilever beam of the double-fork beam.

[0014] Optionally, in the above equivalent calculation method for the torsional stiffness of an aircraft plane-symmetric double-fork beam wing, in Step 1, the box section composed of the wing panel and the beams is simplified into a beam, with a hollow square-shaped cross section.

[0015] Optionally, in the above equivalent calculation method for the torsional stiffness of an aircraft plane-symmetric double-fork beam wing, in Step 3, applying a torque T along the x-direction at point O of the double-fork beam O and calculating the torsion angle θ at point O of the double-fork beam O is specifically as follows:

[0016]

[0017]

[0018]

[0019] Wherein,

[0020] q is the ratio of the torsional stiffness to the bending stiffness of the front beam OA and the rear beam OB;

[0021] L0 is the length of the equivalent cantilever beam of the double-fork beam.

[0022] Optionally, in the above equivalent calculation method for the torsional stiffness of an aircraft plane-symmetric double-fork beam wing, in Step 4, applying a torque T along the x-direction at point O of the equivalent cantilever beam of the double-fork beam O , which represents the torsion angle θ' at point O of the equivalent cantilever beam of the double-fork beam O , is specifically as follows:

[0023]

[0024] wherein,

[0025] G'J' is the torsional stiffness of the equivalent cantilever beam of the double-fork beam.

[0026] Optionally, in the above equivalent calculation method for torsional stiffness of an aircraft plane-symmetric double-fork beam wing, in step 5, let θ' O =θ O , to obtain the torsional stiffness of the equivalent cantilever beam of the double-fork beam, which is specifically as follows:

[0027]

[0028] According to at least one embodiment of the present application, in the above equivalent calculation method for torsional stiffness of an aircraft plane-symmetric double-fork beam wing, the box section composed of the wing wall plate and the beam is simplified into a beam, with a hollow square cross section. Brief Description of the Drawings

[0029] Figure 1 is a schematic diagram of applying a torque T along the x-direction at point O of the double-fork beam in the plane-symmetric double-fork beam calculation model provided by the embodiment of the present application; O

[0030] Figure 2 is a schematic diagram of the cross sections of the front beam and the rear beam of the double-fork beam provided by the embodiment of the present application;

[0031] Figure 3 is a schematic diagram of applying a torque T along the x-direction at point O of the equivalent cantilever beam of the double-fork beam provided by the embodiment of the present application; O

[0032] To better illustrate the present embodiment, some components in the drawings may be omitted, enlarged or reduced, which do not represent the size of the actual product. In addition, the drawings are only for illustrative description and shall not be construed as a limitation to the present patent. Detailed Description of the Embodiments

[0033] To make the technical solution and its advantages of the present application clearer, the technical solution of the present application will be further clearly and completely described in detail below with reference to the accompanying drawings. It can be understood that the specific embodiments described herein are only part of the embodiments of the present application, which are only used to explain the present application, not to limit the present application. It should be noted that for the convenience of description, only the parts related to the present application are shown in the drawings, and other related parts can refer to the conventional design. On the premise of no conflict, the embodiments in the present application and the technical features in the embodiments can be combined with each other to obtain new embodiments.

[0034] ​​Furthermore, unless otherwise defined, the technical or scientific terms used in this application description shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "upper," "lower," "left," "right," "center," "vertical," "horizontal," "inner," and "outer," etc., used in this application description to indicate relative direction or positional relationship are used only to indicate relative orientation or positional relationship, and do not imply that the device or component must have a specific orientation, or be constructed and operated in a specific orientation. When the absolute position of the described object changes, its relative positional relationship may also change accordingly, and therefore should not be construed as a limitation on this application. The terms "first," "second," "third," and similar terms used in this application description are used only for descriptive purposes to distinguish different components, and should not be construed as indicating or implying relative importance. The terms "a," "one," or "the," etc., used in this application description should not be construed as an absolute limitation on quantity, but should be construed as indicating the existence of at least one. The terms "including," "comprising," etc., used in this application description mean that the element or object preceding the word covers the element or object listed after the word and its equivalents, without excluding other elements or objects.

[0035] Furthermore, it should be noted that, unless otherwise explicitly specified and limited, terms such as “installation,” “connection,” and “linkage” used in the description of this application should be interpreted broadly. For example, a connection can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; or it can be a connection within two components. Those skilled in the art can understand its specific meaning in this application according to the specific circumstances.

[0036] The following is in conjunction with the appendix Figures 1 to 3 This application will be described in further detail.

[0037] The box segment composed of aircraft wing panels and beams can be simplified into a beam with a corresponding cross-sectional shape. In the equivalent calculation method for the torsional stiffness of the aircraft planar symmetric double-forked beam wing provided in this application, the planar symmetric double-forked beam wing is simplified into a double-forked beam with a corresponding cross-section. A planar symmetric double-forked beam calculation model is established. Based on the fact that the double-forked beam and the equivalent cantilever beam have the same torsional angle at the load application point under the same torque load, a calculation formula is constructed. In this way, the torsional stiffness of the double-forked beam equivalent cantilever beam can be quickly calculated. And the torsional stiffness of the planar symmetric double-forked beam wing can be checked and designed according to the magnitude of the torque load. In a specific embodiment, the specific process is as follows.

[0038] Step 1: Simplify the box segment composed of wing panels and beams into a beam with a U-shaped cross-section, and establish a planar symmetric double-forked beam calculation model. The double-forked beam consists of a front beam OA and a rear beam OB, both fixed at point O. They are symmetrically distributed about the xz plane and have the same material and geometric parameters. The root of the double-forked beam is located on the aircraft's symmetry plane and is fixedly constrained. Figure 1 As shown.

[0039] Step 2: Determine the material and geometric parameters of the double-forked beam: Elastic modulus E = 70000 MPa, shear modulus G = 25925.9 MPa, length L = 1000 mm, included angle α = 60°, and calculate the moment of inertia I = 10005.33 mm based on the cross-sectional shape parameters of the beams. 4 The polar moment of inertia of the front and rear beams is J = 25492.97 mm. 4 The cross-sections of the front and rear beams are as follows: Figure 2 As shown.

[0040] Step 3: Apply a torque T along the x-direction at point O of the double-forked beam. O =10 6 N.mm, calculate the angle of twist at point O of the double-forked beam. in:

[0041] q is the ratio of the torsional stiffness of the front beam OA to the bending stiffness of the rear beam OB.

[0042] L0 is the length of the equivalent cantilever beam of the double-forked beam.

[0043] Step 4: Apply a torque T along the x-direction at point O of the double-forked beam equivalent cantilever beam. O ,like Figure 3 As shown, the torsion angle at point O of the double-forked beam equivalent cantilever beam is... in:

[0044] G'J' is the torsional stiffness of the double-forked beam equivalent to a cantilever beam.

[0045] Step 5: Let θ' O =θ O Calculate the torsional stiffness of the double-forked beam equivalent to a cantilever beam. It can be seen that the torsional stiffness of the double-forked beam equivalent cantilever beam is 3.1345 times that of the torsional stiffness of the front beam OA and the rear beam OB.

[0046] Based on the geometric and material parameters of the planar symmetric double-spandrel wing, a finite element model of the planar symmetric double-spandrel wing was established and calculated. The torsion angle at point O was found to be 0.418024°, which is basically consistent with the calculation result in the equivalent calculation method for the torsional stiffness of the planar symmetric double-spandrel wing of the aircraft provided in this application. It can be considered that the calculation using the equivalent calculation method for the torsional stiffness of the planar symmetric double-spandrel wing of the aircraft provided in this application has high accuracy.

[0047] The technical solution of this application has been described in conjunction with the preferred embodiments shown in the accompanying drawings. Those skilled in the art should understand that the scope of protection of this application is obviously not limited to these specific embodiments. Without departing from the principles of this application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of this application.

Claims

1. A method for equivalent calculation of torsional stiffness of a plane-symmetric double-spar wing for aircraft, characterized in that, comprising: Step 1: Simplify the box section composed of wing panels and beams into a beam, and establish a plane-symmetric double-fork beam calculation model, wherein the double-fork beam consists of a front beam OA and a rear beam OB; the front beam OA and the rear beam OB are fixed at point O, distributed symmetrically about the xz plane, and the root of the double-fork beam is located on the aircraft symmetry plane with a fixed support constraint; Step 2: Determine the material and geometric parameters of the double-forked beams: the elastic modulus of the front beam OA and the rear beam OB. Shear modulus of front beam OA and rear beam OB The lengths of the front beam OA and the rear beam OB The angle between the front beam OA and the rear beam OB The moments of inertia of the front beam OA and the rear beam OB are calculated based on the cross-sectional shape parameters of the double-forked beam. Polar moments of inertia of front beam OA and rear beam OB ; Step 3: On the double-forked beam Apply along the point Torque in direction Calculate the double-forked beam Angle of twist at point ; Step 4: Equivalent cantilever beam in double-forked beam Apply along the point Torque in direction This indicates that the double-forked beam is equivalent to a cantilever beam. Angle of twist at point : Step 5, Order Thus, the torsional stiffness of the double-forked beam equivalent to the cantilever beam is obtained; In step three, on the double-forked beam Apply along the point Torque in direction Calculate the double-forked beam Angle of twist at point Specifically: ； ； ； wherein This represents the ratio of the torsional stiffness to the bending stiffness of the front beam OA and the rear beam OB. The length of the double-forked beam is the equivalent length of the cantilever beam.

2. The equivalent calculation method for torsional stiffness of a plane-symmetric double-fork beam type wing of an aircraft according to claim 1, characterized in that in Step 1, the box section composed of wing panels and beams is simplified into a beam with a hollow square cross-section.

3. The equivalent calculation method for torsional stiffness of a plane-symmetric double-fork beam type wing of an aircraft according to claim 2, characterized in that In step four, the double-forked beam is equivalent to a cantilever beam. Apply along the point Torque in direction This indicates that the double-forked beam is equivalent to a cantilever beam. Angle of twist at point Specifically: ； wherein The torsional stiffness is the equivalent cantilever beam stiffness of the double-forked beam.

4. The equivalent calculation method for torsional stiffness of a plane-symmetric double-fork beam type wing of an aircraft according to claim 3, characterized in that In step five, let The torsional stiffness of the double-forked beam equivalent to the cantilever beam is obtained as follows: 。

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