Low cost composite fabrication methods applied to low observable structure

摘要

McDonnell Douglas Technologies Incorporated (MDTI) is focused on adapting state-of-the-art low cost composite fabrication techniques to high performance, low observable (LO) structure. With increasing emphasis on affordability, future radar cross section (RCS) goals may not be realizable due to the high costs typically associated with LO technology. Much of the cost associated with high performance LO structure is attributed to composite manufacturing techniques that require considerable touch labor and expensive, limited shelf life materials. Rigid foam and honeycomb, for example, require extensive machining to achieve desired final net shapes. The use of a mold-to-net-shape foam core eliminates expensive machining. This paper focuses on the building block approach MDTI used to demonstrate affordable material and process approaches for fabrication of a large LO structure. This approach consisted of simultaneous development of: 1) an MDTI mold-to-net-shape core material identified as thermoplastic syntactic foam (TPSF), and 2) resin film infusion (RFI) technology applied to LO materials and structural configurations. The demonstration article selected for this technology was an eight-foot-long leading edge. MDTI was successful with first time fabrication of the eight-foot-long leading edge because of the building block approach described herein. Developments from this program are applicable to current and future, manned and unmanned aircraft.