Abstract
This paper gives the results of a study aimed at the characterization of the parameters affecting the formability of aromatic polyamide based honeycomb materials. Specifically, panels of 12.7 mm thick Nomex/phenolic honeycomb were flexurally deformed in an oven to produce permanently curved surfaces while still maintaining the structural integrity of the honeycomb material. The forming temperature, pre-forming soak time, and forming rate were varied for two densities of honeycomb in each of two forming directions (parallel and perpendicular to the ribbon). Degradation during forming was rated by the extent of cell distortion, cell wall buckling, and/or node bond failure occuring on the curved surface. Minimal soak time and an oven temperature of 505K resulted in the best quality panels. The optimal forming orientation was determined for each core density and an empirical relationship was developed to relate the forming rate to density and radius of curvature. The results additionally indicate that cell geometry may be a critical variable affecting formability.