A Calculation Method for the Stiffness Control of Mouth Frame

Abstract

The invention belongs to the technical field of airplane structural design, and relates to a mouth frame stiffness control calculation method. The mouth frame stiffness control calculation method comprises the following steps: calculating a warp value of any angular point of the mouth frame by virtue of a point-surface control theory; calculating the overall warp value of the mouth frame by virtue of a spatial straight line crossing method; calculating an arch rise value of any side of the mouth frame by virtue of the maximum arch rise principle; calculating the maximum warp value of any angular point, the maximum overall warp value and the maximum arch rise value of the mouth frame, and comparing with mouth frame stiffness control indexes. According to the mouth frame stiffness control calculation method disclosed by the invention, control of the mouth frame stiffness is realized by adopting three different calculation modes, the mouth frame stiffness is accurately, effectively and simply measured, design of the mouth frame structure can be intuitively guided, programmed calculation can be passed in the whole process, the method has universality, and the mouth frame design efficiency is improved.

Description

technical field [0001] The invention belongs to the field of aircraft structure design, and relates to a control calculation method for mouth frame stiffness. Background technique [0002] In aircraft structure design, in order to meet specific performance or use requirements, openings of specific sizes need to be made on the skin or airtight partitions. In order to meet the strength and rigidity requirements, a reinforced frame must be arranged around the opening, such as cockpit window frames and various door frames. Due to factors such as the long life requirements of the transparent parts and the airtightness requirements of the door, the reinforced frame around the large opening must have certain rigidity requirements. At present, the stiffness control of the mouth frame is mainly to control the overall deformation ε to be less than or equal to the control value δ. [0003] In order to achieve the above control requirements, at present, the displacement value ε of any...

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Problems solved by technology

[0004] In the design of aircraft structure, if the above method is used to control the stiffness of the mouth frame, when a small control value δ is selected, the mouth frame and its surrounding structures must be designed very strong to ensure that the overall deformation is small, so that lead to increased structural weight

When a large control value δ is selected, the deformation of the mouth frame area will be large. If the deformation trend of the mouth frame is inconsistent, it will cause a large load on the transparent part (window) due to its deformation, which will reduce the service life of the transparent part. Or the airtight performance of the whole machine (door frame area) cannot be guaranteed, etc.

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