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Full-Text Articles in Mechanical Engineering
Improving Student Learning Experience In An Engineering Graphics Classroom Through A Rapid Feedback And Re-Submission Cycle., Vimal Viswanathan, Maria Charlton
Improving Student Learning Experience In An Engineering Graphics Classroom Through A Rapid Feedback And Re-Submission Cycle., Vimal Viswanathan, Maria Charlton
Faculty Publications, Mechanical Engineering
Improving Student Learning Experience in an Engineering Graphics Classroom through the Mastery Approach Pictorial representation of three-dimensional objects has been one of the oldest forms of communication. Engineering graphics courses deal with the art of documenting three dimensional objects in two-dimensional format. Prior literature shows that graphics communication is a key skill for an engineer to possess. However, students in engineering graphics classrooms struggle to understand the concepts being taught due to a variety of reasons including poor visualization skills, limited class time, huge class sizes and unavailability of simple demonstrations. Most of the schools offer this course in the …
Methods Of Extrusion On Demand For High Solids Loading Ceramic Paste In Freeform Extrusion Fabrication, Wenbin Li, Amir Ghazanfari, Ming Leu, Robert Landers
Methods Of Extrusion On Demand For High Solids Loading Ceramic Paste In Freeform Extrusion Fabrication, Wenbin Li, Amir Ghazanfari, Ming Leu, Robert Landers
Faculty Publications, Mechanical Engineering
Fabrication of highly dense parts with complex geometry by paste-extrusion-based solid freeform fabrication processes requires a precise control of the extrusion flow rate to dispense material on demand, which is often referred as Extrusion-On-Demand (EOD). The extrusion process for aqueous ceramic pastes is complex and difficult to control due to their non-Newtonian behavior, compressibility and inhomogeneity. In this study, three methods of EOD (based on ram extruder, needle valve, and auger valve) are introduced and investigated for the extrusion of high solids loading (i.e., >50%, volumetric) aqueous alumina paste. Optimal extrusion process parameters for these methods are determined through printing …
Optimal Rastering Orientation In Freeform Extrusion Fabrication Processes, Amir Ghazanfari, Wenbin Li, Ming Leu, Robert Landers
Optimal Rastering Orientation In Freeform Extrusion Fabrication Processes, Amir Ghazanfari, Wenbin Li, Ming Leu, Robert Landers
Faculty Publications, Mechanical Engineering
Many researchers have tried to optimize the build direction of additively manufactured parts to minimize the vertical staircase effect. However, the horizontal staircase effect should also be considered when fully dense parts are to be fabricated. In this paper, part inaccuracy due to the horizontal staircase effect is considered in order to determine the optimal rastering orientation in building the part. An algorithm is developed to estimate this inaccuracy and a technique is proposed to minimize it. The effect of rastering orientation on staircase errors is examined, and the particle swarm optimization method is used to determine the optimum rastering …
Planning Freeform Extrusion Fabrication Processes With Consideration Of Horizontal Staircase Effect, Amir Ghazanfari, Wenbin Li, Ming Leu, Robert Landers
Planning Freeform Extrusion Fabrication Processes With Consideration Of Horizontal Staircase Effect, Amir Ghazanfari, Wenbin Li, Ming Leu, Robert Landers
Faculty Publications, Mechanical Engineering
An algorithm has been developed to estimate the “horizontal” staircase effect and a technique is proposed to reduce this type of geometrical error for freeform extrusion fabrication processes of 3D “solid” parts. The adaptive rastering technique, proposed in this paper, analyzes the geometry of each layer and changes the width of each line of the raster adaptively in order to reduce the staircase error and increase the productivity simultaneously. For each line, the maximum width that results in a staircase error smaller than a predefined threshold is determined for decreasing the fabrication time or increasing the dimensional accuracy, or both. …