Forming stretch broken carbon fiber composites into complex shapes

Substantial process cost reductions have been shown to accrue from application of automated forming techniques to composite components conventionally manufactured by hand lay up. Wide scale application of such techniques to continuous fiber systems has been limited by inprocess laminate wrinkling. Improved formability associated with fiber axis stretch mechanisms allowed in Stretch Broken Carbon Fiber (SBCF) materials may permit extension of proven process economies to fabrication of more complex components. This paper describes a process development and material evaluation initiative that led to successful fabrication of bead stiffened structures normally restricted to metallic materials. Based on a thorough understanding of process physics, as characterized in specially devised deformation tests, a technology was engineered that exploits the unconventional forming attributes of these emerging material forms. The paper concludes with a suggested optimal process sequence and configuration that may provide for application of cost effective forming technologies on a broader spectrum of complex geometries.