Method for producing structures of complex shapes of composite materials

Abstract

The invention concerns a method for producing a composite material part having a so-called non-strippable shape which consists in producing mold components, or cores, which are to be extracted from the part after the composite material has been cured. The method consists in a first step in producing a core from an elastomeric bladder (21) the desired shape of which is obtained by filling the bladder with a granular solid material (31) and in depressurizing the bladder and in a second step, after setting the core and the composite material (12) in modifying in controlled manner the volume of the core for example by selecting the solid granular material based on its thermal expansion properties or by acting on the pressure in the bladder.

Description

Technical field [0001] [01] The present invention relates to the field of manufacturing complex-shaped components made of composite materials, requiring molds during manufacturing operations. More specifically, the method of the present invention uses a mold element, which is embodied in the member at the time of manufacturing the member, and then taken out so as to be able to manufacture the aforementioned non-moldable member. Background technique [0002] [02] A component made of a composite material that includes fibers in a matrix, such as a resin, is most often manufactured by means of a mold that provides the shape of the component to the material used. [0003] [03] The fibrous, dry or pre-impregnated material of the resin is placed on the mold. The mold must conform to the shape and undergo a more or less complex processing cycle, which may include a resin injection phase and / or application Pressure and / or heating stage. [0004] [04] After the resin is hardened, usually ...

AI Technical Summary

Problems solved by technology

These dimensional changes are generally unacceptable for the manufacture of high performance composite members, such as those with Structural members of narrow (serrée) geometric tolerances for precise assembly, and the dimensional characteristics of the composite member are often as critical as the structural soundness of the material of the final (finie) member, which should not contain air bubbles or Porosity, resin packets, "dry" fibers, the above phenomena can lead to a large production scrap rate, and when the component is subjected to stress in service (sollicitation en service), and they are also a source of delamination, the said Stresses lead to oversizing of members whose structural strength should be necessary

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