Innovative Hole Making Process in Woven Composite Laminates

Abstract This paper proposes an innovative hole making manufacturing method for the composite laminates. The laminates were fabricated using heated vacuum assisted resin transfer molding (HVARTM) technique using plain weave carbon fibers and epoxy resin. Plain weave carbon fabric laminae were stacked together, and five metal pins were inserted in dry fabric at specific distances without causing any damage to the carbon fiber strands. The stacked plies were then infused with epoxy resin to fabricate laminates, which were about 2.6 mm (0.1″) thick. The laminates were cured as per the manufacturer specifications and after curing metal pins were popped out from the laminate. This resulted in holes in the panels without any damage to the continuous carbon fiber strands. The fabricated laminates then were cut into open hole compression coupons using a water jet machine to obtain holes precisely at the center of the coupon. From the remaining panel, ten coupons were machined and half of them were drilled using traditional drilling machine and the remaining half were drilled by nontraditional water jet machining process. The coupons were then tested using ASTM D6484 method to study the mechanical properties of the laminates. The present method shows promising fabrication technique to create holes in the composite laminates without sacrificing the integrity of the continuous fibers.