Method for determining dimension of rectangular beam section of low-speed flutter main beam model of airplane

Abstract

The invention belongs to the field of structural mechanics and relates to a method for determining the dimension of a rectangular beam section of a low-speed flutter main beam model of an airplane. The method is characterized by adapting to the situation that the half width a of a rectangular section is smaller than the half height b of the rectangular section or the situation that J / Ix<1.69, wherein Ix refers to vertical inertia moment and J refers to polar inertia moment. The method for determining the dimension of the rectangular beam section with a lug piece comprises the following steps of: calculating the half width ar and the half height br of the rectangular section when the rectangular beam without the lug piece has the vertical inertia moment Ix of a preset value and the polar inertia moment J of a preset value; adjusting the polar inertia moment J with the preset value; calculating the half width a and the half height b; and calculating the half width 1 of the rectangular beam section with the lug piece when the rectangular beam with the lug piece has lateral inertia moment Iy of a preset value and the thickness of the lug piece is t. The method disclosed by the invention has the advantages of increasing the rigidity precision of the section of the model, reducing the uncertainty of model design, shortening the time for determining the dimension of the section, and increasing the design efficiency of the flutter model.

Description

technical field [0001] The invention belongs to the field of structural mechanics, and relates to a method for determining the size of a rectangular beam section of an aircraft low-speed flutter main beam model. Background technique [0002] For the flutter model design of aircraft with large aspect ratio wings, the structural form of the single-beam model is widely used in structures such as wings, fuselages, and empennages. In order to meet the design requirements of three-dimensional stiffness, a rectangular section with lugs is an ideal design form. [0003] In the past, it was usually necessary to obtain the required section size by trial and error. The trial and error method has the following disadvantages: First, the adjustment of the section size data requires the experience of the designer, and the size data given by experience often has a large error, and it may even be difficult to adjust the size that meets the design requirements, which affects the model. The ...

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Problems solved by technology

The trial and error method has the following disadvantages: First, the adjustment of the section size data requires the experience of the designer, and the size data given by experience often has a large error, and it may even be difficult to adjust the size that meets the design requirements, which affects the model. Accuracy of section stiffness, increasing uncertainty in model design

Second, to determine the size of the section by trial and error, multiple rounds of manual adjustment and judgment are required, which takes a long time and is inefficient, seriously affecting the model design cycle

When J / I x <1.69, the design error will increase

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