초록 ▼

A subfloor structure of an aircraft airframe, particularly of a helicopter, includes longitudinal beams and crossbeams that intersect each other and are interconnected to form a grid that is fixedly attached to the floor and the bottom skin of the aircraft fuselage. Structural elements such as pyram

A subfloor structure of an aircraft airframe, particularly of a helicopter, includes longitudinal beams and crossbeams that intersect each other and are interconnected to form a grid that is fixedly attached to the floor and the bottom skin of the aircraft fuselage. Structural elements such as pyramid frustums and reinforcements are arranged on the beams. The longitudinal beam and the crossbeam have a trapezoidal cross-section that is preferably open on the wider base side, closed by a spine web along the narrow side, and bounded laterally by inclined leg webs that extend downwardly from the spine web at an angle outwardly relative to each other. The subfloor structure grid effectively absorbs the energy of a crash impact having both axial or vertical as well as non-axial or lateral impact force components.

대표청구항 ▼

1. An aircraft floor construction comprising a subfloor structure, a fuselage floor supported and secured on a top of said subfloor structure, and a fuselage outer skin secured on a bottom of said subfloor structure,wherein said subfloor structure comprises a plurality of beams including longitudina

1. An aircraft floor construction comprising a subfloor structure, a fuselage floor supported and secured on a top of said subfloor structure, and a fuselage outer skin secured on a bottom of said subfloor structure,wherein said subfloor structure comprises a plurality of beams including longitudinal beams and crossbeams that are connected to each other, wherein said longitudinal beams intersect and are interconnected with said crossbeams only at respective intersection areas so as to form a grid of said beams with open areas between neighboring ones of said longitudinal beams and neighboring ones of said crossbeams, wherein each one of said beams consists of a respective fiber reinforced composite material, and comprises an upper spine web and two leg flanges extending downwardly from said upper spine web and outwardly non-parallel relative to each other so that each one of said beams has a trapezoidal cross-section that is bounded by said upper spine web and said two leg flanges and that has an open base plane which is opposite, parallel to and wider than said upper spine web, wherein said leg flanges respectively include flange walls and strengthening reinforcements provided thereon, wherein said strengthening reinforcements are selected from the group consisting of corrugations, stamped deformations and stiffening beads on said flange walls of said leg flanges, and wherein said flange walls of said leg flanges are solid, continuous, imperforate walls of said respective fiber reinforced composite material.