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Full-Text Articles in Mechanical Engineering
Trajectory Planning Of Non-Gravity Aligned (Nga) Segments In Arbitrary Directions For Large Scale Additive Manufacturing Of Metals (Lsamm), James Logan Mcneil
Trajectory Planning Of Non-Gravity Aligned (Nga) Segments In Arbitrary Directions For Large Scale Additive Manufacturing Of Metals (Lsamm), James Logan Mcneil
Doctoral Dissertations
Traditionally, slicing and path planning are done along the gravity-aligned direction of a part, causing more complex geometrical shapes to have unsupported overhangs. Wire Arc Additive Manufacturing (WAAM) has typically handled overhangs with a robotic part positioner; but, to extend the current capabilities of LSAMM, a new framework for slicing and building parts out of gravity alignment has been developed. The proposed framework focuses on segmenting more complex geometrical parts into gravity-aligned (GA), non-gravity aligned (NGA), and transition zones to support tool-path generation. GA and NGA segments can be planned with traditional slicing techniques, but the NGA tool-paths must be …
Vibration Behavior In Modulated Tool Path (Mtp) Turning, Ryan William Copenhaver
Vibration Behavior In Modulated Tool Path (Mtp) Turning, Ryan William Copenhaver
Doctoral Dissertations
This project studies the process dynamics and surface finish effects of modulated tool path (MTP) turning. In MTP turning, a small amplitude (typically less than 0.5 mm), low frequency oscillation (typically less than 10 Hz) is superimposed on the feed motion by the machine controller to intentionally segment the traditionally long, continuous chips. The basic science to be examined is the vibration behavior of this special case of interrupted cutting, which is not turning because the chip formation is intentionally discontinuous and is not milling because the time-dependent chip geometry is defined by the oscillatory feed motion, not the trochoidal …
Performance Evaluation Of Polyurethane Composites Using Vacuum Infusion Process, Mohaned M. Mohamed
Performance Evaluation Of Polyurethane Composites Using Vacuum Infusion Process, Mohaned M. Mohamed
Doctoral Dissertations
"Glass fiber-reinforced polymer composites have promising applications in infrastructures due to their low cost, high specific stiffness/strength, and corrosion resistance. The pultrusion process is often used to manufacture glass fiber-reinforced polyurethane (PU) composite. The objective of this study is to use thermoset PU resin to manufacture high quality composites for infrastructure applications using vacuum assisted resin transfer molding (VARTM) process. Using VARTM to fabricate PU resins presents unique challenges. Several modifications however have helped with overcoming these problems. In part I of the research, the mechanical performance of two different PU resin not only evaluated but also compared to one …