Evaluating AFP Producibility

With Automated Fiber Placement (AFP), multiple iterations are required between part programming and part design. To be producible, a design must account for the curvature of the surface and the material limits such as drapeability (material steering), ply angle deviation from nominal, and overlap/gap allowance. A reasonable prediction of actual manufacturing results, obtained through programming and design software, can be achieved by creating AFP paths and analyzing how they actually lay on tool surfaces. This information could be subsequently fed back into the part design process. Without these vital software tools, this information would not be available until NC programming creates the actual NC program for the AFP lay-up machine. When a problem is discovered at this late stage, and the design must be modified as a result, significant delays can occur.
 
With programing and design software tools, a composite part designer, mechanical engineer or process engineer can access the necessary information to determine part produceability. By putting this information in the hands of the upstream decision makers time can be saved, resources can be conserved, and more-producible designs can be developed. Using these tools the part designer or engineer can easily create and experiment with various AFP path options and evaluate how AFP lay-up affects a composite part’s design intent. By producing actual AFP lay-up courses that can be used to program AFP fabrication equipment in the workshop, the user can measure and evaluate the effects of AFP path trajectory, material steering, surface curvature, course convergence and other process constraints as they would be applied during the manufacturing process. Simulated fiber path geometry can be written to various CAD formats for further evaluation by the user’s existing analysis methods and tools.
 
Factors that affect producibility:
•    Fiber angle deviation tolerance
•    Course overlap and gap
•    Material conformance to curved surfaces
•    Material steering
•    Ply boundary shape
•    Machine limits and capability