T. Marusich, S. Usui, D. A. Stephenson, L. N. Zamorano, Third Wave Systems, Minneapolis, MN; A. J. Shih, University of Michigan, Ann Arbor, MI
Aerospace manufacturing relies heavily on drilling processes. Aerospace drilling operations focus on holes for rivets loaded in shear in aluminum, titanium and composite stack-ups. Optimal chip flow and tool life are often in competition with burr formation, general hole quality and cycle time. Physics-based modeling of drilling processes can provide insight and information not readily available or easily obtained from experiments, and in a much faster time frame. A three-dimensional finite element-based model of drilling is presented which includes fully adaptive unstructured meshing, tight thermo-mechanically coupling, deformable tool-chip-workpiece contact, interfacial heat transfer across the tool-chip boundary, and constitutive models appropriate for process conditions and finite deformation analyses. Explicit modeling of entrance, steady-state and exit modeling of aluminum and titanium materials, as well as metal stack-ups is performed. Drilling through stack-up layers is also shown. The modeling includes both solid twist and indexable drills. Metal cutting tests are performed and comparison with predicted data is provided.
Summary: Aerospace manufacturing relies heavily on drilling processes. Aerospace drilling operations focus on holes for rivets loaded in shear in aluminum, titanium and composite stack-ups. Optimal chip flow and tool life are often in competition with burr formation, general hole quality and cycle time. Physics-based modeling of drilling processes can provide insight and information not readily available or easily obtained from experiments, and in a much faster time frame.
