Innovative E-beam cured structures for aircraft

摘要

The use of advanced organic matrix composites is seriously limited by difficulties in producing large complex structures from two-dimensional materials forms such as preimpregnated tape or fabric, and by high costs associated with conventional thermal curing. In a program to evaluate low cost alternatives, Foster-Miller has employed flat intersecting braiding technology in conjunction with E-Beam resins developed by Oak Ridge National Labs (ORNL) to fabricate flat and curved integrally stiffened panels. Preforming techniques and equipment were developed to allow formation of large-scale continuous intersected curved preforms from standard OP sized carbon fibers. Radiative cocure was demonstrated of an F Beam-curable VARTM resin with the YLA 3K prepreg, and a number of alternate routes to integration of the large scale stiffened structures were identified. Two large scale demonstration structures were fabricated by VARTM using low cost polymeric tooling. These demonstration structures were designed by Lockheed Martin Aeronautics Company, Fort Worth (LMA), processed at Acsion in Pinawa, Manitoba, and subsequently characterized by Lockheed. Details of the textile preforming, VARTM, E-Beam curing and mechanical and physical testing are discussed. Results of cost modeling are also presented. These results indicate that significant savings can be achieved using this approach.