Justin West, Tony Schmitz
Department of Mechanical Engineering and Engineering Sciences UNC-Charlotte null Department of Mechanical Engineering and Engineering Sciences UNC-Charlotte
Wire arc additive manufacturing (WAAM) uses an electric arc to locally melt and fuse wire to build parts layer by layer. The benefits are a high deposition rate, dense final structures, and compatibility with light metals such as
Emma D. Betters1, Justin West1, Mark Noakes2, Andrzej Nycz2, Scott Smith2, Tony L. Schmitz1
1Department of Mechanical Engineering and Engineering Science
UNC-Charlotte, Charlotte, NC
2Manufacturing Demonstration Facility Oak Ridge National Laboratory, Oak Ridge, TN
In machining processes, the machine structure, spindle, holder, tool, and workpiece collectively compose a dynamic system that defines the ideal cutting parameters when machining. In an effort to improve the stiffness of a machining center or other machine structure, the base can be designed to increase the stiffness and damping. However, traditional casting processes for machine bases are geometrically limited, labor intensive, and expensive to produce. An alternative approach is to use an additive manufacturing process to form a machine base with the design freedom to enable arbitrary internal features. These features can be used to shift the structural dynamics of the system to a desired natural frequency or to minimize the dynamic response at a given frequency, for example.A pair of demonstration components were designed and produced to showcase the ability of the wire arc additive manufacturing (WAAM) process to print internal features which can be designed to alter the structure’s dynamics (e.g., by altering the natural frequency or increasing the dynamics stiffness). The first component was a simple open channel attached to a base. The second component was identical, but contained a dynamic absorber, designed to minimize the displacement response at the natural frequency of the open design, in the open internal cavity. The design and finite element analysis validation of the dynamic absorber, the additive and subtractive manufacturing processes, and a comparison of the frequency responses for the final components have been completed.