Civil aircraft keel beam structure for improving comprehensive performance of structure

Abstract

The invention provides a civil aircraft keel beam structure capable of improving the comprehensive performance of the structure. The civil aircraft keel beam structure arranged in the middle fuselagecomprises a central wing box section structure arranged at the front end, a main landing gear cabin box section structure arranged at the rear end and an H-shaped supporting frame arranged above the main undercarriage cabin box section structure; and the H-shaped supporting frame supports a main landing gear cabin and transmits distributed loads. The undercarriage cabin has a double-closed-chamberstructure formed by an original single-closed-chamber structure, the torsional rigidity of the middle fuselage is improved, deformation at the position is reduced, the area of the undercarriage cabinis increased, and installation space is provided for multiple devices in the undercarriage cabin. The central wing box and the undercarriage cabin section are supported in the normal flight process of an airplane; when the airplane falls and collides, the keel beam makes contact with the ground the structure can be damaged in time, energy generated by collision can be absorbed, so that the overload borne by the body of a passenger is reduced; and thus the survival probability of the passenger in an airplane accident is increased, and the falling adaptability of the airplane is improved.

Description

technical field [0001] The invention relates to a keel beam structure of a civil aircraft, in particular to a keel beam structure of a civil aircraft for improving the comprehensive performance of the structure, and belongs to the technical field of civil aviation structures. Background technique [0002] In the civil aircraft structure, the keel beam is one of the important components of the fuselage structure, just like the "spine" of the aircraft, and its structural integrity directly affects the flight safety of the aircraft. Since the wings are docked through the central wing box in the middle fuselage section, the main landing gear is retracted in the middle fuselage, resulting in a large opening at the lower part of the middle fuselage. The loads of the front and rear fuselages must be transmitted through the keel beam, which is one of the most stressed structural elements in the fuselage structure. It mainly bears the longitudinal axial force caused by the longitudin...

AI Technical Summary

Problems solved by technology

[0005] On the whole, the existing technology mainly has the following defects: The main disadvantages of the keel beams of Boeing Company are that the long flanges have a long force transmission route and are not easy to maintain, and the long flanges need to be replaced as a whole when they need to be replaced, which greatly increases the cost

However, the keel beam of Airbus does not directly support the central wing box, and additional processing parts are required to ensure the connection between the central wing box and the keel beam, which increases the processing and assembly steps and increases the cost.

In addition, the keel beams of the two companies do not support the upper wall in the landing gear compartment. For wide-body passenger aircraft, the lateral span of the landing gear compartment is larger than that of narrow-body passenger aircraft. The lack of support on the upper wall is affected by passengers and Large deformation after equipment pressure

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