United States of America As Represented by the Secretary of the Air Force

Frances L Abrams

Steven R LeClair

Ronald A Servais

Joseph W Hager

John B Park

Patrick H Garrett

C William Lee

Richard B Hall

A new apparatus and method for making a carbon or graphite reinforced composite is described. A rigid carbon foam preform is placed within a sealed flexible bag. A vacuum is created within the bag. Matrix resin is introduced into the bag, through an inlet valve, and is amply impregnated into the preform. The resulting resin-filled preform is exposed to a heat source to cure the preform. The resulting carbon or graphite reinforced composite structure is then removed from the bag.

Carbon or graphite foam reinforced composites

An automated, close-loop system for controlling the autoclave cure of fiber reinforced composites uses multiple expert systems hosted on different microprocessors running concurrently to control the cure process. This qualitative process controller uses sensory feedback to determine matrix material state-of-cure and then makes control decisions and executes control commands to the autoclave to attain desired material properties. The sensory information is interpreted and translated into a qualitative cure-state description by a system known as a parser hosted on a 68000 processor. The cure state description is then analyzed by the expert system known as the thinke hosted on another 68000 processor. The control decisions are determined using symbolic logic programmed as a rule-based paradigm generated from a human expert on the cure process. Once made, these control decisions are then posted to a blackboard hosted on an 80286 processor for execution by the autoclave feedback controller.

Qualitative process automation for autoclave cure of composite parts

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New Carlisle, OH, United States of America

Frances L Abrams