A calculation method for the hoop stress of fuselage bulkhead under airtight load

Abstract

The present invention discloses a method for calculating hoop stress of a fuselage rib under an airtight load, and belongs to the technical field of aircraft structure mechanics. The method comprises: firstly, allocating a cross-sectional area of a long girder at a fuselage rib onto a fuselage skin, to obtain a combined thickness tx; further, carry out calculation to obtain a radial distribution force T per unit circumference of the rib according to the combined thickness tx; next, calculating an axial stress sigma of the fuselage rib under the action of a pressurization load according to the radial distribution force T; then, by combining a distance e between a cross-sectional centroid after combination of the fuselage rib with the fuselage skin and a neural surface of the fuselage skin, calculating a bending moment M after the combination of the fuselage rib with the fuselage skin under the action of the pressurization load; and finally, calculating a bending stress of inner and outer edges of the fuselage rib under the action of the bending moment M. According to the method, the axial stress of the common frame under the pressurization load of the cabin can be rapidly and accurately obtained, the conventional method of obtaining the stress of the common frame by infinite element modeling and analysis is changed, and the working efficiency is increased.

Description

technical field [0001] The invention belongs to the technical field of aircraft structural mechanics, and in particular relates to a method for calculating the hoop stress of a bulkhead of a fuselage under an airtight load. Background technique [0002] The common frame is a typical structural component in the fuselage structure of transport aircraft. The main function of the common frame is to maintain the shape of the fuselage, improve the compression stability of the stringer and improve the stability of the skin together with the stringer . From the point of view of the loading situation, the ordinary frame does not bear large concentrated loads, and the loads it bears are mainly distributed loads such as airtight loads, aerodynamic loads, and inertial loads. The small concentrated load generated by the system support. Among them, the airtight load is one of the most severe load cases for ordinary frames. [0003] At present, the stress analysis of the common frame of...

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Problems solved by technology

[0003] At present, the stress analysis of the common frame of the fuselage generally adopts the finite element analysis method, and the engineering calculation method is limited to the calculation of the stress of the common frame when the overall bending of the fuselage; there is no effective engineering method for the stress calculation of the common frame of the fuselage under airtight loads. calculation method

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