Forming Composite Features Using Steered Discontinuous Fiber Pre-Preg

Abstract

Interlaminar features of a composite structure are laid up by placing and steering individual chopped fiber pre-preg segments onto a substrate.

Description

BACKGROUND INFORMATION[0001]1. Field[0002]The present disclosure generally relates to fabrication of composite laminate structures using fiber pre-preg, and deals more particularly with a method and apparatus for forming composite structural features by steering discontinuous fiber pre-preg onto a substrate with desired fiber orientations.[0003]2. Background[0004]The strength, stiffness and load transfer characteristics of a composite laminate structure may be optimized through control of fiber orientation during the layup process. Conventional composite laminates may be laid up using pre-preg tapes, tows or broad goods, employing either automated fiber placement equipment or hand placement techniques to layup the material. Generally, the resulting composite structure exhibits substantially consistent structural properties throughout. In some cases, however, it may be necessary or desirable to control the thickness and / or fiber orientation in local areas of a composite laminate in o...

AI Technical Summary

Benefits of technology

The patent text describes a method and apparatus for fabricating composite features of laminates that provide increased control over feature thickness and fiber orientation in local areas of the laminate structure. This allows for optimal structural properties in tight contours and transitions in laminate thickness. The amount of composite material required can be reduced by recycling scrap pre-preg, resulting in cost savings. The use of discontinuous fiber pre-preg allows for greater control over laminate thickness variations and smooth transitions between differing features of the laminate structure. It also results in composite features with higher fiber content.

Problems solved by technology

The ability to control local thickness / fiber orientation is limited using current fabrication processes.

For example, automated fiber placement equipment may be used to steer continuous tows onto the substrate, but the radius of curvature that can be achieved is limited, thus making control of fiber orientation difficult in local areas having tight contours.

Achieving close control over thickness and / or fiber orientation in local areas of laminate may also be costly and time-consuming.

Also, the use of discontinuous fiber pre-preg may result in composite features having a higher fiber content.

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