The Boeing Company
Ply stackings for solid laminate stiffened panel

Abstract:

A composite panel includes a plurality of segments, wherein each segment includes a plurality of reinforcement plies such as carbon fiber plies. Collimated fiber bands (e.g., carbon fibers) within each reinforcement ply are oriented in a single direction, which can be, for example, 0.degree., 45.degree., 90.degree., and -45.degree.. Each segment can include a stack of reinforcement plies, wherein the collimated fiber bands of each reinforcement ply are oriented in one of these directions. The orientations of the collimated fiber bands that form the reinforcement plies in a stack determine a stiffness of the stack and the segment that includes the stack. The stiffness of each segment is controlled to reduce a stiffness mismatch between adjacent segments that form the composite panel, thereby reducing separation of the segments during use.