초록 ▼

A tooling concept uses a compliant forming surface for forming composite parts. The tooling concept utilizes a rigid support substructure that has a thin compliant forming surface. In the preferred embodiment of the invention, the tooling concept is used to form a composite sine wave spar. A preferr

A tooling concept uses a compliant forming surface for forming composite parts. The tooling concept utilizes a rigid support substructure that has a thin compliant forming surface. In the preferred embodiment of the invention, the tooling concept is used to form a composite sine wave spar. A preferred embodiment of the tooling concept includes upper and lower tool inserts and side tool inserts. The upper tool insert has a compliant forming surface that is located in between a rigid support substructure and the composite material used to form the composite part. Composite prepreg is laid up over a sine wave contour on the upper and lower tool inserts to form upper and lower U-shaped composite workpieces. The upper and lower tool inserts and workpieces are then brought together to form a sine wave I-beam. Radius fillers are then applied to the intersections between the upper and lower composite workpieces and cap strips are placed over the flanges of the joined composite workpieces. Side tools and end tools are then placed around the joined upper and lower tool inserts. The resulting assembly is covered with a breather cloth, baked in a vacuum bag and cured in an autoclave. During curing, the autoclave applies a hydrostatic pressure on the upper tool insert and thus compliant forming surface. The compliant forming surface in turn applies a consolidation and forming pressure to the composite workpiece within the tools. During curing, the compliant forming surface deforms slightly to account for thickness variations in the composite workpiece in order to produce a better quality formed composite part.

대표청구항 ▼

[ The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:] [1.]1. A method of forming a composite sine wave spar having a central sine wave web having at least one side and opposing spar caps, comprising the steps of:(a) making a female mold ha

[ The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:] [1.]1. A method of forming a composite sine wave spar having a central sine wave web having at least one side and opposing spar caps, comprising the steps of:(a) making a female mold having a forming surface contoured to the desired shape of at least one surface of the sine wave spar;(b) at least partially filling the female mold with an uncured, castable RTV rubber material;(c) lowering a rigid substructure into the female mold to at least partially displace the uncured RTV rubber material so that the RTV rubber material forms to the contour of the interior of the female mold to define the contour of a compliant forming tool mold surface and at the same time forms around at least a portion of the rigid substructure;(d) curing the RTV rubber material to form a compliant forming tool having a compliant covering around at least the portion of the rigid substructure, the covering being a high density elastomer having a durometer hardness of about 75 shore A and being able to withstand elevated temperatures and pressures suitable for curing resin matrix composites in an autoclave supported by the rigid substructure for maintaining dimensional tolerances on the surface of the compliant forming surface;(e) laying up a composite material over the compliant covering of the tool on the mold surface;(f) placing additional tools in a cooperative relationship with the compliant forming tool having the compliant covering wherein the assembled set of tools define the dimensions of the composite sine wave spar; and(g) using the assembled set of tools following step (f) to consolidate and cure the composite material at elevated temperatures and pressures in an autoclave to form the composite sine wave spar to a predetermined dimensional tolerance.