This dissertation targets the development of the Automated Dry Fiber Placement (ADFP) process in combination with Vacuum Assisted Resin Infusion (VARI), which allows producing high-performance aerostructures (i.e., fuselage panels, etc.) at a reduced cost in comparison with conventional composite manufacturing techniques. Using Vacuum Assisted Resin Infusion (VARI) at high temperature, epoxy resin can be infused into the bed of dry fibers made by Automated Dry Fiber Placement to make the composite laminate.
The resin flow rate depends on the permeability of the dry fiber preform, which is dependent on the preform fiber volume fraction. Automated Dry Fiber Placement (ADFP) allows the capacity to control the fiber volume fraction in terms of gaps between the tows. So, reducing the fiber volume fraction of preforms by introducing gaps into the preform pattern can increase the through the thickness permeability. On the other hand, introducing gaps in the pattern results in a drop in the mechanical properties of the laminate (such as compressive modulus and strength). An optimum gap size may provide a significant gain in the through the thickness permeability with minimum loss in compressive properties.
In this thesis, firstly, process challenges in ADFP and VARI processes, including the formation of various defects, are identified, and solutions to overcome them are introduced. Second, process parameters for ADFP and VARI are introduced. Thirdly, this thesis investigates the effect of the increasing gap size in the preforms layup on the through the thickness permeability of the preform and compressive properties of the laminate. Finally, in this thesis, four fuselage panels were fabricated using ADFP and VARI at high temperature (inside oven), and the quality of obtained laminates was analyzed.