Abstract

This work presents the design, development, and analysis of the Fiber Encapsulation Additive Manufacturing (FEAM) system developed at the Laboratory for Additive Manufacturing Robotics \& Automation at the Lyle School of Engineering at Southern Methodist University. The innovation introduced by FEAM is the ability to insert a continuous fiber of different material into the flowing extrudate. Correctly positioning the fiber feed inside the extrudate while turning the fiber in arbitrary directions is a critical aspect of the technology. This will allow for the full exploitation of the capabilities of the FEAM technology to produce robotic components that actuate and sense. Several compensation strategies for fiber placement are proposed and implemented after recording and analyzing data to characterize the FEAM process. The FEAM technology consists of a tube that guides a coaxial fiber underneath the melt flow of a material extrusion based nozzle. The fiber has to be fed into the flow parallel to the path direction that is co-planar with the horizontal motions. To achieve this a the horizontal motion axes are mounted atop a rotary axes and synchronous motion between these three axes is programmed to maintain the direction. Once the fiber is underneath the melt flow, the extrudate flows around the fiber and encapsulates it as part of the freezing process. Due to the behavior of this process the fiber will end up off-centerline during certain printing configurations that include higher planar velocities and small radii of curvature. A procedure to investigate this behavior is developed and used to quantify the phenomenon. The provided data informs several strategies to compensate in effort to accommodate higher process performance and wider range of design parameters in during printing. These strategies involve limiting angular velocity, anticipating the displacement by biasing the guide, and utilizing the rotary motion underneath the planar axes. Of these the most improvement to the FEAM process was observed in the guide biasing strategy, followed by the angular velocity ceiling. The rotary biasing of the guide against the planar direction had mixed results with no clear benefit.

Degree Date

Spring 5-18-2019

Document Type

Dissertation

Degree Name

Ph.D.

Department

Mechanical Engineering

Advisor

Dr. Edmond Richer

Second Advisor

Dr. Paul S. Krueger

Third Advisor

Dr. David Willis

Fourth Advisor

Dr. Xin-Lin Gao

Fifth Advisor

Dr. Thomas Carr

Subject Area

Mechanical Engineering

Number of Pages

122

Format

.pdf

Creative Commons License

Creative Commons Attribution-Noncommercial 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial 4.0 License

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