Method for machining fully wrapped composite foam sandwich rib

Abstract

The invention discloses a method for machining a fully wrapped composite foam sandwich rib. PMI foam is adopted as a sandwich material inside, the outer surface is fully wrapped by carbon fiber woven cloth to form a composite material shell, and a groove is formed in the upper surface of the rib for arranging a solar cell panel. A female mold and a vacuum bag are adopted for vacuumizing curing forming, a rib mold comprises a lower mold body, an upper mold body and an embedded block, the carbon fiber woven cloth is applied to each exposed surface of the PMI foam before curing, and a bundle of carbon filaments is embedded in the lap joint position of the carbon fiber woven cloth so as to guarantee the continuity and lap joint strength of a carbon fiber laying layer, so that the fully wrapped composite foam sandwich rib is obtained. The wing rib obtained through the machining method is light in weight, the weight of a single rib with the chord length of 275 mm is 14.9 g, and the average density is 114.2 kg / m<3>; the strength is high, and the phenomena of layering and fracture are avoided under 10-time aerodynamic force load; and the rigidity is high, and the maximum deformation of the rib is 0.3 cm under the 10-time aerodynamic force load.

Description

technical field [0001] The invention belongs to the field of aircraft design, and relates to a method for processing fully-wrapped composite material foam sandwich ribs, specifically a new type of composite material with high strength, rigidity, light weight, and continuous carbon fibers covering each surface. Foam sandwich rib method. Background technique [0002] Most aircraft use wing ribs to support the skin and transmit aerodynamic forces. For near-space solar-powered drones, composite materials are usually used as wing rib materials in order to reduce the structural weight as much as possible. The pure carbon fiber ribs obtained by the existing laminated rib processing method are thick and heavy, which will lead to serious overweight of the solar drone; the composite foam sandwich rib obtained by the existing sandwich laminate rib processing method , Only the two sides of the wing rib are wrapped with carbon fiber, and the local foam is exposed, with low strength and ...

AI Technical Summary

Problems solved by technology

The pure carbon fiber ribs obtained by the existing laminated rib processing method are thick and heavy, which will lead to serious overweight of the solar drone; the composite foam sandwich rib obtained by the existing sandwich laminate rib processing method , only the two sides of the wing rib are wrapped with carbon fiber, and the local foam is exposed, with low strength and poor stiffness. When subjected to a large aerodynamic force, it is prone to degumming and delamination, which will lead to structural failure of the solar drone under large overload.

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