Lightweight Integrally Stiffened Composite Structure

Aurora’s Integrally Stiffened SBCF Panel (ISSP) design and manufacturing approach is a replacement for honeycomb panels. It relies upon the unique forming capability provided by Stretch Broken Carbon Fiber (SBCF), which is unidirectional, collimated short carbon fiber filaments in a prepreg tape format. Uncured SBCF is formed through “stretching” similar to plastic forming of metal, allowing complex shapes to be easily produced at significant layup savings. However, after forming and cure, the discontinuous SBCF filaments provide almost the same strength and stiffness as conventional continuous fiber composites. SBCF forming to date is for single surface skins such as shear webs with formed stiffening beads. While significant labor savings result, these configurations are not suitable for external panels, where many honeycomb parts are used. ISSP features a double skin panel –a smooth outer, air passage skin and a beaded inner skin – to provide structural efficiency and light weight of a sandwich panel, but without a core. The ISSP manufacturing process, successfully demonstrated, produces panels in a single cure cycle. A detailed Trade Study to validate weight and cost vs. a honeycomb baseline design will be conducted in collaboration with Sikorsky and Bell to establish weight, quality and manufacturing costs trade.